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Advice on building a 7A race engine

7.3K views 30 replies 12 participants last post by  ShavedQuattro  
#1 ·
Here's the facts, just the facts:

1 year into building a 4000q racecar for NASA's "GTS" series
Have a huge amount of suspension work done: B4 front struts, B3 rear (both modded for camber) race bushings/mounts, bearings, CV's, rear brakes done,master cyl. upgrade.
Car is stripped w/ basic cage, cleaned up and partialy prepped.
Currently working on dash, gauges and underhood/dash wiring.

Now to be clear, THIS IS A BUDGET BUILD (I know, you can't build a cheap race car!), so no $15k engine build!

I'm looking for advice on the engine: this will be an E85 engine
7a, stock bottom end, maybe basic refresh with hone, bearings and rings
Head; rebuilt with some moderate port work (geared toward exhaust efficiency)
TURBOCHARGED: I got the inspiration from 034's 7A turbo kit:

http://www.034motorsport.com/www.03...chargers-and-accessories-turbo-kits-turbo-kit-7a-audi-20v-cylinder-p-19679.html

I'd like to run moderate boost 7.5-15psi, stock 10:1 comp and tune the engine for maximum torque (and maximum response/no lag), keep the revs below 7k to save the engine.
A small inter-cooler (possibly from a 5k), water injection and E85.
I have a 034 1C ready to go for engine management.
I want to see 300lbs ft. at the crank and close to the same amount of horsepower.
Question is, what turbo do I use?
What will give me the least amount of lag?
What port work will give the best mid range power?
What else needs to be done to improve drive-ability? intake ports? intake manifold? exhaust manifold??

I've planned to spend 2013 on the engine, 2014 on development, driving non competition track days,
late 2014,early 2015 competition!

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#2 ·
I run a gt28rs on the s4 that I've been hillclimbing. should suit your power levels and I have no complaints in the spool dept. Also, that is a lot of gauges that you will never have time to look at. Two simple red lights in the dash are what I consider ideal. One for oil press and one for temp.

I run a stock Exhaust mani, and stock intake for an AAN. No porting needed. If its a budget build, run stock AAN manifolds, a reasonable intercooler (not a 5k intercooler) and spend the savings from port work on track time. I also cannot stress how much fun hillclimbs are. I do have a pretty good sized oil cooler and oil temps get excited pretty quickly.

Test fit some seats, I think you'll find that the stock front seat mount gets in the way pretty quickly. Might want to cut it out now before you get too far.

The main hoop is interesting... any particular reason for bending the feet in so far?
 
#4 ·
I would think that you should at least go with some nice forged pistons like what yodasfro had for sale a while back. Just to help with longevity. Also, with the b4 front hubs and b3 rear hubs your front wheels will stick out a little further.
 
#6 ·
The 07k could easily reach your goals almost in NA trim. People are getting 200whp NA. Because the engine is littered with audi rings, and is made by VAG, it would be swapable and still stay in NASA rules. It would be lighter, shorter, package better, offer a cheap replacement and not need a built motor to reach your goals and be reliable. The 07k is going to flow more in stock form than most heavily modified 20v heads on this site. IT will rev to 8500 without modifications.

Just another option
 
#7 ·
ShavedQuattro said:
The 07k could easily reach your goals almost in NA trim. People are getting 200whp NA. Because the engine is littered with audi rings, and is made by VAG, it would be swapable and still stay in NASA rules. It would be lighter, shorter, package better, offer a cheap replacement and not need a built motor to reach your goals and be reliable. The 07k is going to flow more in stock form than most heavily modified 20v heads on this site. IT will rev to 8500 without modifications.

Just another option
07k
What engine is that??
 
#11 ·
Hank, it's hard to see the life of a race car exceeding 5 years. i think he'll have more issues finding body panels in 10 years than replacement engines.

On the flipside, 07k is on my upgrade list.

End of the day quickest way to get on the track. a motor swap is peanuts when you have a completed car.

Also if the cage is legal, run it. I'd seriously consider some rethinking for the next main hoop. ACQ on this board has some great pictures in his thread as to why a well done/overdone cage is imperative.
 
#12 ·
ShavedQuattro said:
If you look really hard, but most are in that 400-650$ range with under 50k miles. Question is, will you be able to find a 7a for 200$ in 10 years?
Yeah, I have to depend on my local pick 'n pull... they're starting to get new VW bugs and A4's with tons of V6's..
I'm hoping they'll get some of the new 5cyls soon...
 
#14 ·
With over 70% of all jettas being sold with 2.5L engines, and the sales figures for the Jetta in North America being around 125,000 per year since 2005, It is safe to say there won't be a shortage of 07k's in the upcoming years. Wish I could say the same for hte roughly 8000 20v aan, 3b or 7a's in the country.
 
#21 ·
ShavedQuattro said:
With over 70% of all jettas being sold with 2.5L engines, and the sales figures for the Jetta in North America being around 125,000 per year since 2005, It is safe to say there won't be a shortage of 07k's in the upcoming years. Wish I could say the same for hte roughly 8000 20v aan, 3b or 7a's in the country.
OK Mr. Hank!

Here's some questions about the swap:

Is this engine ever used in a "longitudinal" configuration"??
What flywheel/clutch do I use?
Will the 4000 "016" input shaft fit in the 07K's pilot bearing??
what about the throw out bearing and slave cyl?
Will the bell housing bolt up?
Will the oil pan clear the subframe?
What do I use for engine mount brakets (I assume I have to make my own)?
Is this engine easy to convert to 034 1C EFI??
Does it have any kind of variable intake or variable cam timing I have to control...?
 
#22 ·
Is this engine ever used in a "longitudinal" configuration"?? ---No, but that doesn't mean it isn't possible
What flywheel/clutch do I use?---- we have a flywheel that accepts 7a clutch kits
Will the 4000 "016" input shaft fit in the 07K's pilot bearing??-------- yes, but i would strongly recommend a torsen based trans for any road racing anyway(01a or 01e)
what about the throw out bearing and slave cyl?-------plug and play using 016 or 01a/01e stuff
Will the bell housing bolt up?-----yes
Will the oil pan clear the subframe?-------we have an oil pan
What do I use for engine mount brakets (I assume I have to make my own)?------have you covered
Is this engine easy to convert to 034 1C EFI??----------Yes, the motor has an internal 60-2 wheel built in and vr sensor, just need to wire it up
Does it have any kind of variable intake or variable cam timing I have to control...?----Yes, has Variable intake. You can control it with a GPO, or mechancially ditch the VVT by choosing which one you want, low end or high end. You can do anythign inbetween if wired via a GPO

Hope that helps.
 
#24 ·
ShavedQuattro said:
Is this engine ever used in a "longitudinal" configuration"?? ---No, but that doesn't mean it isn't possible
What flywheel/clutch do I use?---- we have a flywheel that accepts 7a clutch kits
Will the 4000 "016" input shaft fit in the 07K's pilot bearing??-------- yes, but i would strongly recommend a torsen based trans for any road racing anyway(01a or 01e)
what about the throw out bearing and slave cyl?-------plug and play using 016 or 01a/01e stuff
Will the bell housing bolt up?-----yes
Will the oil pan clear the subframe?-------we have an oil pan
What do I use for engine mount brakets (I assume I have to make my own)?------have you covered
Is this engine easy to convert to 034 1C EFI??----------Yes, the motor has an internal 60-2 wheel built in and vr sensor, just need to wire it up
Does it have any kind of variable intake or variable cam timing I have to control...?----Yes, has Variable intake. You can control it with a GPO, or mechancially ditch the VVT by choosing which one you want, low end or high end. You can do anythign inbetween if wired via a GPO

Hope that helps.
I thought this was 01E only. You really have my attention now... 250-300 HP N/A seem reasonable?