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Audi V8 into a Gen2 Toyota MR2

79K views 234 replies 29 participants last post by  cbulen 
#1 ·
01/24/2008 update:

I have launched a new website for this project.

Project MV8R: Sign up for free newsletter

12/11/2008 EDIT:
Announcing the world's first 2nd generation MR2 with a V8 that actually runs/drives! Go to page 6 of this thread for photos: http://www.motorgeek.com/phpBB2/viewtop ... &start=125

UPDATE: also see page 7 for more pix: http://www.motorgeek.com/phpBB2/viewtop ... 992#292992

Original Post:
There is a lot of interest in the MR2 community of putting a V8 into the Toyota Mk2 (mark 2 aka 2nd generation) MR2 chassis (1991-1995 in the USA, and 1991-1999 in the rest of the world).

Bill Strong with his Cadillac NorthStar V8 in the Mk1 chassis, which he calls "ToyStar" www.v8mr2.com has been an inspiration for us for some time. However, he cut the car severely (most of us are not willing to go that far). Additionally, we have working against us, is the fact that the Mk2 have a NARROWER engine compartment than the ealier generation. (Please note that the motor is transverse in all years/gens of MR2).

Back when I bought my car, I had intended from the start to do a Toyota V6 with a Turbo swap. Some others have attempted to use the Toyota 4.0 Liter V8 ( engine code 1UZ-FE) in the Mk2 chassis, but so far, no one has completed a swap. This engine also requires extreme cutting of the unibody subframe and shock towers, due to the engine length.

I decided to take a different approach. I am not so mired in the "keep it in the family" mentality, so I did a survey and search for all compact V8 engines that were readily availble used. The first obvious choice was the Yamaha/Ford SHO 3.4 motor used in the mid-90's Taurus SHO car. However, this motor is NOT much more powerful and torquey than the MR2 Turbo 4 cylinder motor. It would be easier and more cost effective to just hop up our current motors. And that's even before we get to the Cam sprocket issues the SHO had.

Anyway, eventually, I found out about the Volvo XC90 motors, but these are still very rare and very expensive ($4500 to $5000, no accessories).

That led me to the Audi motors.

Hilly's project on this forum with the Audi motor swap into his '81 Esprit gave us a LOT of insight as to what we are up against. http://www.motorgeek.com/phpBB2/viewtopic.php?t=9648

I am starting this project thread, to let you all know what we are up to, and to hopefully, get some technical input on this swap.

I have already outlined the project, and tried to anticipate as many issues as I could. Since Motorgeek members are not able to view posts on MR2OC, without becoming members (Free to do by the way), I have re-posted many things below.

and post your questions or comments to this thread in MotorGeek.

Thank you everyone!

cbulen
 
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#2 ·
Isn't the Mr2 motor mounted transverse? Although the audi V8 engine is a pretty good engine and it's cheap, there are probably better ones out there for what your looking at doing. at 250-300 hp, they aren't the most powerful engines out there so to get some good numbers you need to turbo it, and in that event you can probably get better numbers from a I4 or 3.0 toyo V6.

I recall reading an article where a magazine used a 3.0 V6 from an Avalon and put a supercharger and turbo on it and got some really good numbers (400hp).
 
#3 ·
yes, its transverse. I could not find ANY other V8, besides the new Volvo that is a better fit than the Audi. We only have a total of 21-ish inches of length (see the drawing below) to work with.

Concerning the MR2 V6 swap:
Yes, that was project MR6 by Jeff Hartman. Acutally, he got 600 hp due to being twin-charged (supercharger AND turbocharger), but he spent probably close to 10K for that engine alone, and another 5k for the forced induction, and not sure what else for the EMS, and in the end, he was lifting the heads, and had custom copper HG. He outlines the project in detail in his book: How to Tune and Modify Engine Management Systems.

http://www.amazon.com/Modify-Management ... 559&sr=8-3

The 3.0 V6 that most of the MR2 guys do is only 200hp stock and about the 200 ft-lbs torque. BTW, this is the same numbers as the stock MR2 turbo motor (3S-GTE) that I have, but the V6 has a wider torque curve.

It is definetly the easier/cheaper swap to do. The aluminum V6 (called the 1MZ-FE) is limited by its pistons and crank. Brad Bedell www.bedellracing.com is the guru for the 1mz conversion, and he was breaking cranks at 500 hp (300 hp on a blower, and a 200 hp shot NOS). He WON the Sport Compact Car Magazine Ultimate Car Contest a few years ago, and the advertisers for SCC did NOT appreciate it, because most of them sell parts for much newer cars like the WRX STi and Evo MR's. Needless to say, the following year, another MR2 was entered, and they made sure it would not win. The MR2 is a fantastic car, and performance value for the money, but it is no longer made, and most are 14+ years old.

Some of us use the iron block 3VZ (found in Toyota cars) and 5VZ (found in Toyota trucks) motors. Again, it takes forced induction just to get to the 300 hp mark.

I would rather put a lightweight alum V8 in, starting with 300 HP, and go up from there. Not to mention, the V6 don't have the torque of a V8.

And there is the coolness factor. I want a "manly" motor!
I love the Ascari (esp the A10)
but I can't afford one! I can't even afford an Ultima (not to mention, its ugly), and even if I could, I am too cheap. I want a poor man's Ascari, or Ferrari killer.

If I really wanted to go easy/cheap, i would just buy a used 97-2004 Corvette. But, that's not really the point.
 
#4 ·
BTW, I have a request for some technical info: Does anyone have a dyno printout for the 97-99 ABZ motors (chassis or motor dyno). I would like to know what the redline is, what the torque curve looks like, and where peak HP occurs.
 
#5 ·
I'm not hatin your project, in fact I think it's pretty cool!

The Audi V8 is probably one of the most compact units I've seen, and the chain drive models are even more compact. You might also consider a VR6, its approximatley the size of a 4 cylinder and with displacements from 2.8 to 3.6 liters. With a turbo the sky's the limit! And the VR engines make a ton of torque down low where it matters.

The big prob with the V8 is that your looking at custom internals for low CR pistons, and main bearings cannot be had by the aftermarket, although I did find a set from an RS6 for approx 700 usd.

As Nate can attest to, boosted engines like to drop valves :).
 
#7 ·
Nate didn't tell me about the valve issue. I asked about boosting the 3.6 and 4.2, but in fairness to him, I was specifically asking about cylinder wall thickness issues. What is the dropped valve issue, and is there a solution?
 
#8 ·
cbulen said:
Nate didn't tell me about the valve issue. I asked about boosting the 3.6 and 4.2, but in fairness to him, I was specifically asking about cylinder wall thickness issues. What is the dropped valve issue, and is there a solution?
The dropped valve issue has to do with old heat cycled parts. the portion of the valve stem that is secured by the keeper cracked at the track which caused the valve to drop into the cylinder and.. well.. make a mess.

To avoid it you could either replace the exhaust vales with new replacements or go with something like custom stainless or titanium.
 
#9 ·
a4kquattro said:
scottmandu said:
As Nate can attest to, boosted engines like to drop valves :).
Pretty sure he was running that 4.2 Normally aspirated when it dropped the valve.
I think your right, but it was boosted at one time. I've seen several V8's drop valves, boosted and not, so I'd recommend a valve change before going nuts.
 
#10 ·
scottmandu said:
a4kquattro said:
scottmandu said:
As Nate can attest to, boosted engines like to drop valves :).
Pretty sure he was running that 4.2 Normally aspirated when it dropped the valve.
I think your right, but it was boosted at one time.
not the 4.2, no. That was his 3.6.

I've seen several V8's drop valves, boosted and not, so I'd recommend a valve change before going nuts.
can't disagree there. What are our options?
 
#13 ·
Ford and Rover are both too long by 5-6 inches

Please see posts 8,9 and 10

of our V8 repository of information
Edit: see re-postings below, since you all cannot view MR2OC.com threads

IF we wanted to go V6 with boost we would just use the Toyota V6. Lots of guys have done that swap.

Guys, we have done a lot of thinking and measuring and research into engine choices. The Audi V8 remains the best candidate for a V8 in an MR2. Even Bill Strong's northstar is waaaaay huge, which is why he cut his car up so much.
As of Dec 2008, I no longer believe this. I now believe the Northstar or the older Cadillac 4.9 OHV are the best transverse swap candidates. However, the Audi is the best available (but not ideal) candidate for a longitudinal setup in an MR2.
 
#14 ·
a4kquattro said:
Pretty sure he was running that 4.2 Normally aspirated when it dropped the valve.
I think your right, but it was boosted at one time.[/quote]

not the 4.2, no. That was his 3.6.

Oh okay my bad...

A good stainless valve would be a great replacement. 034 as well as others offer them.
 
#15 ·
cbulen said:
Ford and Rover are both too long by 5-6 inches

Please see posts 8,9 and 10

of our V8 repository of information
http://www.mr2oc.com/showthread.php?t=124095

IF we wanted to go V6 with boost we would just use the Toyota V6. Lots of guys have done that swap.

Guys, we have done a lot of thinking and measuring and research into engine choices. The Audi V8 remains the best candidate for a V8 in an MR2. Even Bill Strong's north star is waaaaay huge, which is why he cut his car up so much.
We aren't knocking you, just trying to make sure you know what your up against. I'd agree the north star engine is way huge for it's displacement.

The BMW 4.0 liter V8 as found in mid 90's 740's and 540's is also a pretty light and compact unit, with better hp numbers than the Audi, and Mercedes also have a V8 of similar vintage with even better numbers. Problem is that all 3 V8 engine have very little support in terms of aftermarket internal parts. (all are considered throw away engines, if something goes wrong in the lower end then give the engine to your dealer as an exchange).

The Porsche 928 motor is massive. The only other smaller engine I can think of is the Lotus Esprit 3.5 twin turbo V8, which would be SWEET, but then why not just keep it in the Lotus I suppose.....
 
#16 ·
No problem, I just wanted you all to know that we tried to think of everything we could have. I admit to not checking into the BMW option. Anyone know the length and width of those motors?
 
#18 ·
What rotation does the mr2 motor turn? I ask cause i have an idiot, I mean friend who thought it fruitful to put a built Honda engine in a pickup only to discover it went very fast going backwards.
 
#19 ·
AFIK, the hondas are the only motors (excepting the S2000 motor) that have reverse rotation.

MR2 are normal rotation. Hopefully, the Pontiac G6 with the 6 speed is normal rotation, as that is the transaxle we plan to use.

I aplogize, I did not know you could not see our posts without being a member.
 
#20 ·
V8 Links:

http://www.britishv8.org/Articles/motors.htm

SIZE / WEIGHT / DISPLACEMENT CHART
In this chart, length is from the bellhousing mounting surface to the front of the water pump pulley, height is from the bottom of the pan to the top of the air cleaner, and width is at the widest point of the engine, including the stock exhaust manifolds. The data supplied by Street Rodder magazine show the Ford engine to be taller than the other two, but most other sources I've seen describe the Chevy engine as taller than the Ford. My own measurements on the Buick V6 (basically the same design as the 215 V8, less two cylinders) indicate that the BOP/R V8 is also taller than the Ford.

Width Length Height Weight
BOP/R 26 28 27 320
Ford 24 29 27.5 460
Chevy 26 28 27 575
Chevy 26 28 27 525
w alum heads

Ford 24 29 27 424
w alum heads

TR6 22 29.5 25 460
Buick V6 26 28 29 412?

The first three entries came from a recent issue of "Street Rodder" magazine, and are reasonably accurate, except for the weights. Without knowing precisely what ancillaries are included, a real comparison can't be made for weights. Length can vary tremendously by the choice of water pump and pulleys, and height will depend on the intake set-up. The fourth entry was obtained by subtracting the weight savings of aluminum heads from the third entry. The last three entries came from my own measurements, and are very precise. The weights given include everything required to make the engine work - starter, alternator, flywheel, clutch, intake, carburetors, exhaust, distributor - everything except oil and water! In this trim, the weight for the Ford in entry two becomes 519 pounds, from actual measurement! The BOP/R and Chevy weights will most likely go up a similar amount in the same trim.
Here's a site devoted to dropping in V8's in cars that never had 'em

http://www.jagsthatrun.com/

Ford engine weights, and external dimensions. About 1/2 down the page: http://www.sullivanperformance.com/YVS4 ... /tech1.htm

Here is some of our thread (my posts)

BTW, Rover V8 overall dimensions: http://www.v8engines.com/engine-4.htm

Found a 6 speed transaxle for V8's by accident:
http://www.v8archie.com/v8Archie/Prod3.htm
I just got back from one of my local wreckers. They had a 1991 Audi V8 (that's the name of the car), and the motor was out. Its a 3.6L V8. From the back of the motor (the bellhousing interface) to the front of the crank pulley, its VERY compact at only 20 inches long (with accessory pulleys about 21 inches). Bear in mind that these measurements eyeballed with a tape measure, and I can't guarantee accuracy.

Unfortunately, the motor is VERY VERY Wide at 28.5 inches if you include the timing belt cover. If you cut the outer most edges off the cover, you are then down to 27.5 inches from valve cover to valve cover. This excludes the large headers the motor comes with, so if you include those, its really wide (I didn't measure that width). So, to fit the Mk2, length wise it might work. I found out how long the G6 trans is, and I am going to go out and jack up my car to see how long the stock turbo trans is.

If you don't mind cutting the car, the older Audi V8 will work. It might only need trunk wall cutting as well. These are very big "mights" by the way.

I also measured a 93 Northstar 4.6 while I was there. Its about 27 wide by 23.75 long.

a 95 Ford 5.0 (mustang) motor is 28 long, 20-21 wide.
if you got a custom or shorter pulley, and eliminated the water pump (go electric), then you can get it down to 24.5 inches long, still not short enough.

A Toyota highlander 3.3 V6 (not sure of year) with VVT-i was 23.5 wide and 19 long

This is interesting: The stock 93 turbo trans (mine) is about 16 inches from the bellhousing mating surface (to engine block) to the rearmost part of the trans housing (extreme driver's side). There is a notch in the MR2 frame that is in the lower 1/2 of the channel, to clear about 1/2" to 3/4" of housing.

The G6 tranny by contrast is 14.25" long according to V8 archie!

Assuming an adaptor plate of about 1/2" thick, this means we might gain another inch of clearance using this tranny. If you are willing to notch the frame even more (this I might be willing to do), then more clearance could be obtained. Axles will need modification, but this may be a non-issue, because modified axles will be needed anyway for the G6 trans. Archie and I talked about combinations of MR2 axles and CV joints and G6 axles and CV joints. All this stuff will need to be figured out at some point.

This might be a good trans to use for V6 swaps. Still need to look into gear ratios and limited slip diffs
Took forever to find this on the internet

2006 GM F40 (Pontiac G6 manual 6 speed, derived from the Saab 9-5 F40 6speed)
1st 3.77
2nd 2.04
3rd 1.32
4th .95
5th .76
6th .62

Final 3.55

Overall gear reduction
1st 13.38
2nd 7.24
3rd 4.69
4th 3.37
5th 2.70
6th 2.20

Kinda short gearing for typical V8. Ideally, we would have around 9.5 to 1 on first gear, if we were using a low RPM V8 (5000 rpm redline small block).

just found this:
http://www.fastfieros.com/tech/2007_f40.htm
2007 GM F40 (weighs 123.5 lbs)
1st 3.77
2nd 2.04
3rd 1.37
4th 1.05
5th .85
6th .71

Final 3.55

Overall gear reduction
1st 13.38
2nd 7.24
3rd 4.69
4th 3.73
5th 3.02
6th 2.52

Comparison: MR2 Turbo tranny (from my 93 BGB):
1st 3.23
2nd 1.913
3rd 1.258
4th .918
5th .731

final 4.285

Overall gear reduction
1st 13.841
2nd 8.197
3rd 5.391
4th 3.934
5th 3.132

Comparison: Pantera ZF transaxle (just happened to have these numbers--must be for later Panteras because it has 6th)

1st 2.23
2nd 1.47
3rd 1.04
4th .846
5th .705
6th .609

Final drive 4.22

Overall gear reduction
1st 9.41
2nd 6.20
3rd 4.39
4th 3.57
5th 2.98
6th 2.57

Note how the GM F40 from the G6 is very similar in overall reduction (this is all that counts) to the ZF 6 speed, from 3rd through 6th. If you had a torquey v8 and were not looking to launch hard, as in everyday driving, you could start out in 2nd each time.

By the way, V8 archie says he supplies an adaptor plate, carrier bearing (for the jackshaft), and carrier block that attaches to the side of the motor (like the MR2). He says that the trans requires a 9 1/8" clutch. He also said the flywheel has to go pretty far inside the housing, so his Chevy small block adaptor plate is 1" thick. So a lot of careful measuring will be required to determine how thick an adaptor plate will need to be to fit another motor to this tranny.

Another technical hurdle: The G6 trans has no provision for the starter motor. The starter is mounted on the engine in the G6 application. Whatever motor is mated to the G6 will need the starter mounted to it, or alternatively, the adaptor plate made for the motor/trans will need a spot for the starter (depends on flywheel diameter).

Another MR2OC member asks:
What about a Volvo V8. I know the engine is a little longer than that but it is very narrow and with the Volvo transaxle maybe it could fit? It was at least designed to be installed transversely and 311hp.
my response:
the new Volvo 4.4 would be GREAT, and would probably work. The cars it comes in cost $60 or $80 something thousand. If you buy me a motor, I will put it in my car
:-D
While I was at the wrecking yard today, I looked at a Ford 4.6 DOHC V8. The thing was friggin' HUGE. It was about the size of my Ford 460 BIG BLOCK that is in my truck.

Here's a comparison between the 4.6 and the old skool 302
http://www.automotiveforums.com/vbullet ... stcount=23
Cutaway of the Volvo V8
http://www.ultimatecarpage.com/pic.php? ... arnum=2078

Block and heads. note the open deck design, and siamesed cylinder bores.
http://www.ultimatecarpage.com/pic.php? ... arnum=2078

Quote:
The new V8 engine marks a new turning-point in Volvo Cars' history. It is the first V8 the company has produced since it was founded in 1927, and the Volvo XC90 is the first model to be powered by the new engine.

In order to maintain overall compactness, all the ancillary units such as the alternator are fitted directly onto the engine itself without any space-stealing brackets. The starter motor is fitted above the transmission for the same reason. What is more, the exhaust camshafts are driven by secondary chains running off the inlet camshafts, saving additional space. The left-hand cylinder bank is offset half a cylinder ahead of the right bank, contradicting normal practice in the automotive world - so the engine can slot neatly into the structural beam network of the XC90 and thus enhance collision safety.

The Volvo XC90 V8 produces 315 horsepower and its torque - the most important characteristic of a V8 engine - is a massive 440 Nm at 3900 r/min. And at the sort of revs at which most driving takes place, around 2000 r/min, no less than 370 Nm of torque is at the driver's disposal. To increase the low end torque, the Volvo V8 has a valve in the inlet manifold that is closed below 3200 rpm. In this mode the air flow between the two cylinder banks is cut off, which creates a broader and more even torque curve.

Engine 60º V8
Engine Location Front , transversely mounted
Displacement 4.400 liter / 268.5 cu in
Valvetrain 4 valves / cylinder, DOHC
Fuel feed Fuel injection
Aspiration Naturally Aspirated
that's 324.5 lb-ft of torque @ 3900 RPM and 273 lb-ft @2000 rpm to us ******* 'mericans
 
#21 ·
Continuing my post above. here are more posts to the MR2 thread:

I contacted about half a dozen engine resellers, and no one has a volvo V8. One guy told me to give him a year!

I contacted lowboost to find out if the 1UZ-FE toyota V8 fit in the Mk2 without cutting the front and rear firewalls. It required cutting the shocktower(s) or frame, because its too long with the adaptor plate and E153.
The 1UZ is 25.8" long (about like a Chevy or Ford small block)
The 1UZ is about 26" wide.

mmmmmm.....possibilities....audi.....
Quote:
Originally Posted by Turbomits95
The 4.2 audi motor is smaller than it appears in that photo. I think it would fit sideways in an mk2.
My response:
Nope, not the newer version of the 4.2 (2003- current). I just got back from my local Audi dealer. I measured a 2004 A8 motor, 4.2L. It is 33 inches wide timing cover to timing cover (or valve cover to valve cover, because unlike the ealier motors, this one has the timing covers flush with the cam covers).
Ok, to summarize:
3S motor + E153 tranny = 36" long

a 1UZ is (conflicting info on this item) 25.8" long + GM F40 = 40" long not including adaptor (add 1") = 41"
= frame/shocktower cut

a older Audi V8 (20.25" long) + GM F40 = 34.5" + adaptor (add 1") = 35.5"
I will have to try very hard to get the adaptor thickness down to .5" This is because about .5" or so of the turbo tranny fits in a notch in the Mk2 frame. I am pretty sure the GM F40 won't go into this notch.
= maybe possible with no cutting

older Audi V8 + E153 = 36.25 + 1" Adaptor = 37.25"
MAY be possible to get this down to a .5" adaptor, 36.75" long.
= frame/shocktower cut

So, the only real question now is can the width of the older Audi V8 be accomodated by the front and rear firewalls?

I have a plan, I am building mockup Audi V8 out of cardboard boxes that is the rough size/shape of the motor, and the trans. I will go down to my local wreckers, where they have a 93 MR2 NA with no motor in it, and stick the mock up in there.
Here is my response to some questions from Mike H, the other MR2OC member I am collaborating with. I am posting it to keep my thoughts on track:

Prior e-mail:
I am trying to locate pictures and gear ratios for the V8 audi box. I am surprised the kit car guys are not using it (or maybe they are). So far, most of those guys are using the smaller lighter box with shorter ratios. http://pr0nsessd.dyndns.org/audi/Audi_01E_trans.html

Current e-mail:
I haven't had a chance to decipher that guy's site. Its very hard to understand, and it appears to be geared (pun, HA!) towards Audi car owners looking for Quattro versions of the Transaxles.

There's two ideal scenarios I am trying to start from and work my way towards what is actually possible. Usually it ends in a situation where we have to cut the car severely. Far from ideal

1) motor mounted longitudinally, coupled with the original trans it came with.
Ideal because: better cooling for the motor, no danger of the engine hitting the car due to engine shake and torque loading of the motor mounts. Possibly easier to work on. No special clutches, flywheels, or adaptors required. This is cheaper for us.
Modified axles still required. Special shifter cables or modified cables needed. Custom motor mounts needed. Possibly a new custom crossmember or severely modified MR2 crossmember is required, if the trans sticks out too far and/or upwards behind the axle centerline..

2) Motor mounted transverse, as in the original MR2. Ideally, it would mate up to the Solara 5 speed, and still fit in our engine compartments. This is where I originally started. Special clutch/flywheel/adaptor plate needed. No special axles or shifter cables. I no longer think this is possible without cutting the car severely, even if the shorter Audi V8 is used (see my thread).

To make scenario 1 possible, the Audi transaxle + V8 motor is the possible answer. EDIT:I no longer think this is possible.
The question is where the axles are in relation to the engine. We can't set the motor/trans back at all or forward either, because CV joints have a lot of friction, and will burn themselves up in no time if we put any angles on them besides what they see when the suspension moves. The outputs of the trans must line up with the center of the wheels. So, does this force the motor beyond the front firewall? I need to measure to find out. Based on the photos of the car that has an Audi inline 5 cylinder in it longitudinally, http://www.cardomain.com/ride/449196
I think the V8 will require firewall removal as well.

To make scenario 2 possible, the G6's GM F40 might be the answer, as its 1.75" shorter than the MR2 or Solara tranny. Special clutch, adaptor, motor mounts and shifter cables (and possibly a shift pattern reversing bellcrank or other mechanism) are required. The only question is engine width, and will it hit the front and rear firewalls.

I am not settled on any trans yet, as I want to explore this longitudinal option.

I was going to go to the wrecking yard today with my cardboard mockup, but I just came down with something, and had to put a few hours in at work this afternoon, so I opted to take a nap instead.

I am hoping to get over to the yard tomorrow. I will try the mockup in the longitudinal as well as transverse.

I believe the Toyota V8 will be too long in either configuration. We are stuck with the Audi motors because Audi worked so hard to make them so short (but apparently didn't worry about going wider!)

I am thinking the older Audi V8 (4.2 liter) will be our best bet, in either configuration. Its easier to find, and cheaper as well. I don't know if it has variable valve timing or not. Maybe you could look into that, while I keep exploring the Audi transaxles

BTW, I have known for a long time that a lot of the Kitcar guys were using Renault transaxles, but these are pretty light duty. I also knew they were using Audi trans from the 4 cylinder cars, but what I did not know was that Audi made a V8 car back in the 90's and that they had 5 and 6 speed manual 'axles.

http://www.lambolounge.com/

BTW, everyone that talks about trans keeps talking about horsepower limitations. This is BS. You can have a motor that spins 10,000 RPM and makes 200 hp (a motorcycle engine), but it can have a light transmission and live a long time, due to low engine torque. This is sort of the thinking behind the stock 3S-GTE and E153 with its very short ~4.28 final drive, and short overall ratios in the lower gears.

The 3 key factors in trans strength are the torque of the motor and the weight of the car, and how hard you launch. Heavier cars, harder launches, and torquey engines all require stronger trans.

If this is what the Audi V8 transaxle looks like (in two wheel drive versions, aka non-Quattro) then it will require extensive cutting of the rear most frame rail of our cars, cutting of the trunk firewall, and trunk floor, and possibly heavy modification of the crossmember http://www.lambolounge.com/Chassis/Tran ... 0/5000.asp

After studying Daniels http://mr2oc.com/showthread.php?t=205536 NorthSouth inline 5 powered MR2 photos, I don't think Longitudinal using Audi trans and V8 is an option.
 
#22 ·
Just thought of another thing I have to figure out: the output axle location relative to the engine centerline on the GM F40 tranny.
I really need a dimensioned or scale engineering drawing of this trans.
Another MR2OC member says:
If the goal is to get 8 cylinders in an MR2 with minimal or no cutting, two more engines to consider:

1) The VW W8. Incredibly short, not too wide, but a bit tall. Rare as hen's teeth, but 4 liters and ~275 HP.

EDIT:

"THE MOTOR
Weighing just 190 kg and measuring only 420mm in length, 710mm in width and a mere 683mm in height, Volkswagen's W8 is two 15 degree V4 engines fused together with staggered cylinder bores and offset at an angle of 72 degrees. However because the 15 degree angle is so narrow, a weight saving has been delivered by using a single cylinder head cover for all four cylinders in each V4."

from: http://www.gizmag.com/go/2082/

That's 16.5 inches long and 28 inches wide...a bit wider than I thought. But this picture:

...makes it look like the widest part may be the accessories, which perhaps could be relocated to narrow it a bit.

2) The Yamaha 3.4l V8 from the last Taurus SHO. I think it was a 60 deg. block. Problem is that you're down to 235 hp and no more displacement than you can get with a more straightforward V6 swap. Still, it's a V8.

-Stephen M
__________________
91T 187k Bone Stock except for audio
MR2 How-To Guides/Last MR2 Road Trip

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My response:
We considered the SHO V8, but decided it wasn't worth the effort due to low power and torque. It would be easier to go toyota V6 turbo.

I didn't know too much about the W and VR6 engines from VW, like the VR6 and W8, etc. After reading about how they solved the DOHC problem for thier VR6, I have to say I am impressed at VW's cleverness.

http://www.autozine.org/technical_schoo ... kaging.htm

It would also explain why I had trouble keeping up with a VW hatch back before I tore my motor down (back when my 3S was still bone stock). He must have had a VR6 in his car, and probably modded. I saw some VR6's at the wrecking yard. I don't know if they were the newer DOHC motors. Anyway, this is a V8 thread, so I will check out the V6 thread and see if anyone is swapping a VR6 into the MR2.

The W8 is very intriguing. But, VW sold 10,000 units per year world wide, from 2001 to 2005. I think its to rare to be practical. http://en.wikipedia.org/wiki/W8_engine

i might have better luck getting the Volvo V8 --in a year or so, HA!
 
#23 ·
Another member comments:
It might not be of much help, but since I've gotten my MR2 a V8 was all I could think of cramming into it. A mini supercar/deathtrap for sure, but could be a hell of a lot of fun. So I set to work trying to find out what I could fit into it. The 1UZ-FE was my first thought like everyone else, but I read it was 6-7 inches too long with transaxle. I ran across an unlikely solution. Ford's 1996+ Taurus SHO model comes with a transverse mount 3.4l V8. Being .6 liters smaller than the Toyota motor I assume it would have far less of a problem being shoe-horned in. The only thing I'm unsure of us is the width fit, because the V8 uses an unusual 60 degree V design. That, and they had a catastrophic failure in the cam design, but it's permanently fixable with some welding. This motor is light with a high red-line potential, so it wouldn't take much modding to get the MR2 to really launch like a bullet. Maybe forged aluminum pistons, ported and polished heads with performance valve-springs, and some exhaust work would open it up nicely.
My response:
You might want to see what develops in this thread with the Audi V8. You can get early 90's 4.2L with 276hp and 295 ftlbs of torque, and the motor is CHEAP to buy.

The SHO made 235 hp and 230 ftlbs of torque. We all can get that EASILY from the 3S all day long. IMHO, the SHO is not worth the trouble. Yes, you could go turbo and get more power, but another problem is availability of these motors used.

Also, what if you started with the Audi with close to 300 hp and 300 ftlbs and THEN :-D went turbo :-D ?
 
#25 ·
MOre research on my part:

I went back to the wrecking yard to get some more measurements.

The question is: will the 90-94 Audi 3.6L fit into the Mk2 chassis transversely without cutting? The short answer is maybe.

I know, not the answer you all were doing the pee-pee dance for.

Here's the gory details

Lengthwise coupled with the Pontiac G6 GM F40, it will fit. Width wise, it fits, but has no room to shake (rock saideways, and there is no space between the firewall and the trunk wall where the headers will be. So, if you are willing to cut the trunk wall out near the top, and box it back in about an inch into the trunk, this motor just might work.

So, physically putting this motor in is possible.

Now for the bad news

The starter is mounted on the motor rather than on the tranny (like the MR2 turbos). The starter is mounted right where the Jackshaft needs to go. There is some other stuff on that side of the bock as well, like the alternator, oil filter, oil cooler. These items are all easy to relocate, I think. The alternator can fit on the other side of the block (just like the guy who did the Lotus Esprit conversion I linked to above) where the AC compressor is--we lose AC of course.

The F40 is not setup to mount the starter either.

Some measurements:

From V8 Archie: G6 F40
As viewed from the rear of the motor
distance from centerline of crank to centerline of jackshaft is 7.75 inches. Archie tells us we need no more than 5.5 inches of engine block between the centerline of the crank and the side of the block in order to mount his jackshaft bearing support. (personally, I think we could work around this).

As viewed from the side of the motor:
The distance from the center of the jackshaft bearing to the edge of the bellhousing is 13.5 inches. Not sure if this includes the adaptor plate

Mike H asked me to measure some Audi transaxles while I was there.

The distance from the edge of the bellhousing to the centerline of the axle output flange is about 7~7.1 inches. The axle flange is located about 3 to 3.5 inches below the centerline of the input shaft where. Sorry for the imprecision. I was on a ladder, using a drywall straightedge, but this should give you an idea about trying to go North-South.

If someone has a REALLY GOOD idea about how to solve this, I am ALL ears.

Here is a picture of the starter problem, and a picture of the F40:

BTW, I have since figured out that the starter actually needs to be lower, at about 7 or 8 o'clock, and the jackshaft will be at 4 or 5 o'clock


 
#26 ·
a post by Mike H:
Here are some numbers that hilly gave me

The approx sizes of the Audi ABZ V8 engine and gearbox are: -

Total length (Audi ABZ engine + 01X gearbox) = 1200mm (47 1/4")
Length of engine (front pulley to bellhousing face) = 490mm (19 3/16")
Length of 01X gearbox (bellhousing to rear casing) =710mm (27 15/16")
Max width of engine (across exhaust manifolds) = 760mm (29 15/16")
Max height of engine (sump to idle air valve) = 660mm (26")
Drive shaft position (front pulley to centre of drive flange) =690mm (or from gearbox rear casing = 510mm) (20") (27 3/16")

Hope this helps

Andy

_________________
2002 A4 1.9 TDi Avant
1981 Lotus Esprit S3 with ABZ 4.2 V8, 01X 6 speed (now)
 
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