Automobiles Forum banner
1 - 20 of 230 Posts

·
Registered
Joined
·
6,501 Posts
Discussion Starter · #1 ·
Well, in the interests of getting this project off the ground sooner rather than later I'm going to opt to go the stock NG bottom end route. I did the CR calculation just to prove to myself that it would work (if anybody thinks some of my constants are incorrect such as 10v or 20v combustion chamber volume PLEASE correct me):

<Warning: math!>

constants:
10v combustion chamber volume: 29cc
20v combustion chamber volume: 38cc
NG bore: 8.25cm
NG stroke: 8.64cm
NG CR: 10:1

now the math:

cylinder volume @ TDC = Vo (volume created by gasket thickness, small area around piston bore above top ring, others(?))

cylinder volume @ BDC = ((pi * (bore / 2)^2) * stroke) + Vo = (3.14 * (8.25 /2)^2) * 8.64 = 461.63cc + Vo

so now I gotta figure out what Vo is...

compression ratio = cylinder BDC volume / cylinder TDC volume

so for the NG:

10 = (461.63 + 29 + Vo) / (Vo + 29)

490.63 + Vo = 10 * (Vo + 29)

490.63 = 9Vo + 290

9Vo = 200.63

Vo = 22.30cc

Sooooo, with the 20v head bolted onto the NG bottom end we get:

20v CR = cylinder BDC volume / cylinder TDC

= (461.63 + 38 + 22.3) / (22.3 + 38 ) = 521.93 / 60.3 = 8.66

</math>

So as others have mentioned, bolting the 20v head onto an NG short block gives you a nice ~8.7:1 CR. Given the fact that I only spent $300 for the head and I can pick up an NG/NF short block for ~$100... who CARES if/when( :D ) I blow it up? I know the rods and pistons might not be as stout, but I think knowing how Audi builds the rest of the 10v motors I can expect at minimum 350hp out of this setup.. maybe more? :p When it finally goes, I'll spend the time/money and build it up using custom pistons/rods and whatnot.. and the best part is that I can just throw it in the car as it will already be setup for the motor.

Thoughts? I'm pretty psyched about the idea of getting this thing running for under $1k in parts, which is beginning to sound totally possible! :woowoo:
 

·
Registered
Joined
·
8,121 Posts
These guys are so wacked. :bump:
I LOVE IT!!!!!thought noone was crazzier than me :bashtard:
love youyr equations though...learnt that in shcool and i thought solving compression ratio was a big problome
thanks much guy!
qustion...why dont you set up your 90quattro frame? or your justa 4K die hard fan?
 

·
Registered
Joined
·
1,063 Posts
Yea,

Funny thing is I posted the 20v,NA block 2 months ago with no response.
We've been running it in the rally car for 2 years now. Marc you may recall
seeing it at MT W with 2 fuel distributers and the rad in the trunk.
I think you gave Paul "A for effort" in the pits.

Aaron
 

·
Registered
Joined
·
1,063 Posts
Actually I'm in the process of helping a friend build one for his 80Q.
What are you using for a headgasket? Thats been the tought part of the combo. We use a NG/NF head gasket with ARP headstuds. I'm sure you figured it out allready.
 

·
Registered
Joined
·
6,501 Posts
Discussion Starter · #6 ·
Wizard-of-OD said:
qustion...why dont you set up your 90quattro frame? or your justa 4K die hard fan?
My 90 is very high mileage (300k) and isn't anywhere near as cosmeticly nice as my 4ktq. ONE of my cars has gotta be a winter beater ya know :) Feature wise the 90 is a better car to turbo, but the 4ktq is already setup as my "toy", so I'll keep goin' with that :p
 

·
Registered
Joined
·
8,121 Posts
mileage is nothing guy
like i say,if your building a performance car,you mjight as well go all out with suspension etc etc
leave the 4k
put the 20V in the 90Q
please?
for me?
Paint it metallic silver...18 inch black wheels, Black bonnet and 20V turbo!
pleasE? :eek:
 

·
Registered
Joined
·
6,501 Posts
Discussion Starter · #8 ·
iduaobrut said:
Funny thing is I posted the 20v,NA block 2 months ago with no response.
I think I saw it but hadn't done any other research on it so I wanted to do some of my own digging before making comments.

iduaobrut said:
We've been running it in the rally car for 2 years now. Marc you may recall
seeing it at MT W with 2 fuel distributers and the rad in the trunk.
I think you gave Paul "A for effort" in the pits.
Yes, I remember seeing that car.. but when I brefely talked with Paul about it I thought he said it was an MC bottom end?? I think he was upset about how the car was running that day ( :curses: ) and seemed a little upset at me asking questions so I didn't bother pressing for any further detals :)

Did you guys do anything to the bottom end at all (different bearings/etc)?

How much power do you think you are currently running through it?

I was pretty amazed lookin at his dual CIS setup, definitely, uh, interesting? :wtf: I have no doubt you guys are pleased with the decision to go with 034efi :woowoo:

as far as what I'm going to do about a headgasket, as I recall, the diameter of eacy cylinder ring on the 3B/AAN HG is 82mm, so I'd only have to take 1/4mm off the outside edge to make it fit perfect. There is plenty of meat on the reinforced ring around each cylinder to take off that small amount of material.

Failing that, I'd explore other OE gaskets (7A maybe?), and as a last resort I'd just o-ring the block and run a copper gasket I suppose. One way or another I'll come up with a gasket that works :p

How did the NG gasket hold up for you?

Oh yeah, and do you know if the 20v studs are longer than the 10v ones? I imagine that they are... bummer since I already have a 10v set of ARP studs :frustrated:
 

·
Registered
Joined
·
6,501 Posts
Discussion Starter · #9 ·
Wizard-of-OD said:
mileage is nothing guy
like i say,if your building a performance car,you mjight as well go all out with suspension etc etc
leave the 4k
put the 20V in the 90Q
please?
for me?
Paint it metallic silver...18 inch black wheels, Black bonnet and 20V turbo!
pleasE? :eek:
Nah, the 90 is staying stock and boring. At least one of my cars has to be reliable :)

As much as none of us like to admit it, pushing the tuning envelope on these cars WILL result in breakdowns. It doesn't make us bad mechanics, (well maybe it just makes me a bad one :tard: )...

Anyway, if I'm going to mod any other car it wouldn't be the 90.. Sometime in the near future I'm going to pick up an UrS4 for daily driving duties, parts runs, etc. Maybe when I mange to pay off Mr. Mastercard and Sir. Discover :frustrated: ?
 

·
Registered
Joined
·
6,501 Posts
Discussion Starter · #10 ·
Nothing in this post, just wanted to be "chirping second" like the rest of you :bump:
 

·
Registered
Joined
·
8,121 Posts
URS4?
what avout a UR quattro..sorry but the URS4 too big...it looks like a limo.
I like 90's cuz i think there sexy
especially with stock bumpers rolling on 18"!
do you have your 90 up and running or your abandoned that?
 

·
Registered
Joined
·
6,501 Posts
Discussion Starter · #12 ·
Wizard-of-OD said:
URS4?
what avout a UR quattro
cool car, but in a toy kind of way. I drive a lot, and things like 3" exhausts and stiff suspensions are great for the track and zooming around for fun, but on long trips something a tad more comfortable is nice to have.

..sorry but the URS4 too big...it looks like a limo.
big, yes.. but it is more of a luxury car while still maintaing serious performance with the AAN motor. Seems like a good choice for a daily driver. I make lots of trips between CT and NH, so a nice comfy sport-luxury ride would be cool.

do you have your 90 up and running or your abandoned that?
of course, I drive that car every day into work. Dead nuts reliable.
 

·
Registered
Joined
·
17,178 Posts
yesterday i was doing my regular drive from oregon to cali and at one of my regular stops the was a urs4, not sure what year it was, but the guy driving it noticed (and seemed surprised!) that i knew what i was looking,so after he finished filling up with premium, he kindly paraded around the station over in front of me, so's i could get a better look see and also noticed his 2bennett license plate frame on the front.
it was nice red red, with stock wheels, but still a very nice car.
not that anybody was asking me,but my dream "limo" as some have put it would be a s55 amg ,I love audi's the more I own and get into them, but I still am most impressed with the engineering and performance of the big benzes.
i just recently downloaded video of a 2002 s600 (twin turbo v12) that ran a 11.62, dead stock, how impressive is that. he beat out a souped up late model supra (with slicks no less), haha, i bet that supra guy was ashamed.
 

·
Registered
Joined
·
1,063 Posts
Hey,

Paul did nothing to the NG lower. He uses the the stock headgasket with the ARP headstuds. The only problem we had was overheating. He melted a head at Maine last year because of a hole in the radiator. After the rally we pulled the head we and found the head melted up real bad. The lower was still good
though and is still in use today. Without the resticter in the turbo (SCCA rule)
we got 500 hp. We calibrated his G-tek with a stock 4kq and got 115 hp so I think its close enough. That was with an RS2 turbo by the way. The dual CIS system made really good power. You can Laugh all you want but he was 4th
on the hill that day. I think Chionere was 1st,Sprongle 2nd (S2 rally car),Gerry Driscoll,3rd,and then Paul. Not bad in my book. I see alot of people dumping alot of cash.. powder coating,shot peening,line boring,
re-ringing,magna fluxing,and for what?To take a drive down main street and sit in the burger king parking lot? Do a quick drag race with a Honda?
The old rally car had an JT lower end with 250,000 miles on it when he started. He raced it for 2 yrs and then put the motor in his street car
for another year. It finally tossed a rod not to long ago. I use the KISS method with my cars "Keep It Simple Stupid". If you plan on abusing the car non stop Spend the money,but if you plan on tearing around on a friday night, why not save your money? You will love the 20V trust me.
You will love it more knowing you only spent $1000 installing it. The rally car is so brutally fast that it makes my guts ache. Its actually really hard to hold the steering wheel when you dump the clutch.

Goodluck,
Aaron
 

·
Registered
Joined
·
6,501 Posts
Discussion Starter · #16 ·
iduaobrut said:
The only problem we had was overheating. He melted a head at Maine last year because of a hole in the radiator. After the rally we pulled the head we and found the head melted up real bad.
bummer! Are you guys still running a trunk mount radiator or did you go with something up front after the melt down?

Without the resticter in the turbo (SCCA rule)
we got 500 hp.
:eek:

Hot damn!

Guess I should stop worrying about breaking the motor, then???

Have you guys ever taken the car to the drag strip or a dyno?

We calibrated his G-tek with a stock 4kq and got 115 hp so I think its close enough.
I love that thing, if nothing else to go and MAKE the HP test runs :woowoo:

That was with an RS2 turbo by the way.
I thought you were running some kind of Garrett based turbo at Mt. Washington.. why the change?

The dual CIS system made really good power. You can Laugh all you want
I actual have to give you guys major props for having the balls to try such a setup. Anybody can go down a path that others have followed, it's always the people trying something new that are the real innovaters.

All that said, I'm sure you are happy with the switch to 034 EFI, yes? :)

but he was 4th
on the hill that day. I think Chionere was 1st,Sprongle 2nd (S2 rally car),Gerry Driscoll,3rd,and then Paul. Not bad in my book.
The fact that you raced at Mt Washington (a road I'd piss myself doing over 60 on in most places) is impressive enough. Placing 4th? Kick ass!

I see alot of people dumping alot of cash.. powder coating
hey hey! I resemble that remark :p

,shot peening,line boring,
re-ringing,magna fluxing,and for what?To take a drive down main street and sit in the burger king parking lot? Do a quick drag race with a Honda?
I actually built my car up that way for the fun of it more than anything. I didn't know nearly as much about building high performance Audi motors when I started my 4ktq project as I do now. I certainly wouldn't have bothered spending money building up the already very robust MC bottom end. I may still have done the P&P work on the head but probably would have done it myself to save money. As far as the powdercoating goes I love the look and will continue to make pretty parts for my motor. In fact I'm throwing a used kitchen oven in my garage so I can start doing it myself 8)

The old rally car had an JT lower end with 250,000 miles on it when he started. He raced it for 2 yrs and then put the motor in his street car
for another year. It finally tossed a rod not to long ago. I use the KISS method with my cars "Keep It Simple Stupid". If you plan on abusing the car non stop Spend the money
even then, maybe not. Definitely learned that I'm better off starting with a setup on the cheap. If it blows up, build it better!

but if you plan on tearing around on a friday night, why not save your money? You will love the 20V trust me.
Can't wait. Just finished watching some vids of highly modded 20vts.. definitely a slightly different tone than the 10vt. I dig it. As it is I often roll my windows down and nail the throttle for no reason in particular just to hear my turbo make music. Passengers think I'm wierd.

My name is Marc, and I have a problem.

You will love it more knowing you only spent $1000 installing it.
hells yeah! I'm all about bang for the buck these days.

The rally car is so brutally fast that it makes my guts ache. Its actually really hard to hold the steering wheel when you dump the clutch.
mmmmmm 4 wheel burnouts.. mmmmmm

Thanks for the info Aaron, I'll try to make it up to some rallies to check out the car/chat/etc.

Later
 

·
Registered
Joined
·
1,063 Posts
Hey,

He had the hybrid for MT W ( ceramic BB),but it ate some dirt so he put the RS2 on for Maine. The radiator moved to the front after MT W when we converted to 034 for Maine. He's almost done with the tube frame 20VT
hillclimber. That car will be super sick! I wish we had a four wheel dyno up here in the great white north. We are lucky to have phone service up here.
If you want a thrill try driving up Pikes Peak. Its crazy at 30 mph. I'm going for the hillclimb this summer with a subie team I crew for. I might drive the 4kq for some fun runs.

Aaron
 

·
Registered
Joined
·
2,351 Posts
Let me get this straight:

You can use the entire NG bottom end? Pistons and all?

This seems way to easy and cheap :D

Steve
 

·
Registered
Joined
·
1,063 Posts
You are very right it is easy and cheap! Thats why nobody does it.
For some reason we think if something is cheap and easy its not going to last.
30psi of boost in a hillclimb on a bone stock lower end is proof enough eh?

Aaron
 

·
Registered
Joined
·
2,351 Posts
Yes, way to easy :D

I think I may have a new project to save up for!

30 psi on stock bottom end and hard rally driving? Wow.

Steve
 
1 - 20 of 230 Posts
Top