7A w/ 034 turbo kit or 20VT swap?

10283 Views 40 Replies 17 Participants Last post by dzynda, Oct 17, 2014

drdds

Discussion Starter · Jun 19, 2013

Does anyone here have the 7A with the 034 motorsports kit? I'm curious how it is. Seems like you don't get full boost until higher RPMs, I always really liked that Audi managed full boost under 2,000 RPMs on their stock motors. No lag and lots of bottom end torque make it an easy city driver. Anyone have experience with the 034 kit?

1 - 20 of 41 Posts

Ruyck

· #2 · Jun 20, 2013

I've got it on my daily driver coupe quattro. I've been running it for 10,000 miles or so. Definitely livens the car up. It feels like what the car should really have had from the factory. Makes me wish the rallx car had a bit more power. I'll agree that there's a bit lacking by the way of low end torque. And 7psi leaves you wishing for a bit more up top. But for a daily driver it ramps up the fun factor ten fold.

I helped a friend of mine install it while he owned the car. He also installed a 3 inch exhaust at the same time. This created a flow issue with the wastegate. The internal wastegate wasn't able to hold 7psi (overboost). I've since installed an external wastegate and open dump tube (lazyness and lack of room), as well as a factory s2 intercooler. I still get the occasional CEL when cruising down the highway. Pulls timing, which is very annoying, but I've been too busy to look into it.

That said, I've also got a 3B swapped car. Having experienced both worlds, I'd say go 20vt if you're in it for the long haul. And if you're looking for easy install and just a much better than stock driving experience, I'd go 7A turbo.

What are your goals?

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Peter Rsa

· #3 · Jun 20, 2013

What about throwing forged rods and pistons in the 7a and really boosting it or is there something else thats not gonna hold up.
I am asking cos I am considering the same thing for a coupe a wanne buy.

Edit:Sorry for the Hijack

drdds

Discussion Starter · #4 · Jun 20, 2013

Edit:Sorry for the Hijack

Don't worry about it

We are looking for similar answers so any info is good for me.

My goals would be a very fun street car that could keep up with similar vintage M3's and the like. I *might* occasionally go for a track day, but since I never have, it's pretty unlikely. I'm looking for a fun daily driver, reasonably reliable to commute in. I would want to keep A/C working and all the creature comforts. For me, I'm not really looking to do a super high performance build. If we had them here, I would have just bought an S2 and made light mods to it.

What about taking the components from a 3b motor and adapting to 7A? Anyone done that? I might have an avenue to pursue that pretty easily. If I had all the components from a 3B motor, how would I get the correct software? I would still need a head gasket to reduce compression, right? What else?

Thanks guys keep the ideas coming.

death 4kqt

· #5 · Jun 20, 2013

i think a straight 3b swap is the best bet. Can be done to be totally oem and as reliable as the 7a.

varia

· #6 · Jun 20, 2013

death 4kqt said:
i think a straight 3b swap is the best bet. Can be done to be totally oem and as reliable as the 7a.

+1 and its cheaper. and at the end you are not limited to 7psi

drdds

Discussion Starter · #7 · Jun 20, 2013

Looks like the only real down side to the 3b swap is the amount of work involved then, correct? I lean more this way since it is sort of a "factory" equivalent. Just fear the amount of labor involved :frustrated: Not only the labor for the swap itself, but all the gremlins that will need attention when I uncover them. Something about the unknown. Then again, just because you don't see them now doesn't mean they don't need fixing!

Seems like many people delete the A/C for one reason or another when doing the swap, I definitely want working A/C when it's done. Anybody here successful with that? And frankly the whole wiring harness thing intimidates me. I re-did most of the wiring on my Ducati last year (charging circuit, starter circuit, adapted a Mosfet R/R etc) but that MUCH less complicated than a factory wiring harness for an Audi! I think I would be capable (particularly with other motorgeekers ;-) ) but the whole prospect is intimidating to me.

death 4kqt

· #8 · Jun 20, 2013

that turbo kit looks like a PITA to me. 3b swap is only a bit more complicated than an engine replacement.

varia

· #9 · Jun 20, 2013

drdds said:
Looks like the only real down side to the 3b swap is the amount of work involved then, correct? I lean more this way since it is sort of a "factory" equivalent. Just fear the amount of labor involved :frustrated: Not only the labor for the swap itself, but all the gremlins that will need attention when I uncover them. Something about the unknown. Then again, just because you don't see them now doesn't mean they don't need fixing!

Seems like many people delete the A/C for one reason or another when doing the swap, I definitely want working A/C when it's done. Anybody here successful with that? And frankly the whole wiring harness thing intimidates me. I re-did most of the wiring on my Ducati last year (charging circuit, starter circuit, adapted a Mosfet R/R etc) but that MUCH less complicated than a factory wiring harness for an Audi! I think I would be capable (particularly with other motorgeekers ;-) ) but the whole prospect is intimidating to me.

Of course it can be done, fairly easily. Hint: very early CQ ac line that runs outside of the engine bay.
And you think the turbo kit will install itself? Maybe an engine swap a bit more work.

The kit is 3K, with shipping and other things. so $4K, 7psi, approximately 200 wheel HP.
Complete 3B/AAN cost $1200-1500, machine shop $300 to refresh the head, $140 head gasket set, $300 new clutch kit, $500 euro LHD harness, ABY oil and air cooler and pipes, hoses $450 from UK. Stage 1 chip $200 = 3.2K this config is more HP, more fun, more boost, less money.

But its your choice

death 4kqt

· #10 · Jun 20, 2013

good post above, a straight healthy 3b swap can be done for much less. And you can modify a 3b harness to work for even more savings.

drdds

Discussion Starter · #11 · Jun 20, 2013

Well it's settled then. I already was leaning toward the 20VT swap and I think I've had enough convincing now that it is the way to go for me.

Now, 3B or AAN? Pros and cons for each? ;-)

varia

· #12 · Jun 20, 2013

drdds said:
Well it's settled then. I already was leaning toward the 20VT swap and I think I've had enough convincing now that it is the way to go for me.

Now, 3B or AAN? Pros and cons for each? ;-)

3B intake fit, AAN wont, while AAN has no distributor ignition.

Toph

· #13 · Jun 20, 2013

The AAN has a more modern ignition system (no distributor), but the 3b has the intake and water manifolds that you will want for an easy swap. I have a 3b in my CQ now, but the AAN I have will be the one I build for more power. I completely changed the intake path (front facing IM), so the 3b isn't really providing any benefit over the AAN, I just didn't have the AAN when I started the project.

Chris beat me to it, but I'm posting this anyway lol

elaw

· #14 · Jun 20, 2013

varia said:
Complete 3B/AAN cost $1200-1500, machine shop $300 to refresh the head, $140 head gasket set, $300 new clutch kit, $500 euro LHD harness, ABY oil and air cooler and pipes, hoses $450 from UK. Stage 1 chip $200 = 3.2K this config is more HP, more fun, more boost, less money.

Also, the head work+gasket and the clutch are things you probably should also do on the 7A unless it's in unusually good shape or that stuff has already been done. So that's either 750 bucks in favor of the 3A or against the 7A.

gh_jeremiah

· #15 · Jun 3, 2014

So you can't really build up the 7a much past 200hp and 7psi without dumping major money into the internals and etc? I love my little 7a and don't really have the place and time to swap the motor and splice harnesses and was trying to figure out the most I could do with my 7a

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audidrums

· #16 · Jun 4, 2014

Here's another scenario, sort of on topic to the OP's question. Suppose you had both a spare AAN and 3B in your possession, and planned to go 20vt a B3 Audi with a 7A engine. To those of you who've completed swaps, what would be your ideal combination of components if you had to do it over again? (Assuming all parts from all three engines are fair game.) Let's also assume Motronic engine management is desired. Go...

paradox11235

· #17 · Jun 4, 2014

AAN engine with 7a valve cover, oil pan, and oil pickup, and 3b intake and water manifolds. AAN makes more power stock and has many more tuning options, 3b intake is easier with the side mount radiator, and you could run 1.8t coils on the 7a valve cover with a little work. Then use the euro goodies to make it all play nicely with the car.

Oh, and a 4000 fan shroud modified to fit the 200 fan.

varia

· #18 · Jun 4, 2014

paradox11235 said:
AAN engine with 7a valve cover, oil pan, and oil pickup, and 3b intake and water manifolds. AAN makes more power stock and has many more tuning options, 3b intake is easier with the side mount radiator, and you could run 1.8t coils on the 7a valve cover with a little work. Then use the euro goodies to make it all play nicely with the car.

Oh, and a 4000 fan shroud modified to fit the 200 fan.

Its a good shopping list, I have a very similar mule but i started with 3B.

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dzynda

· #19 · Jun 4, 2014

Ok the aan makes more power stock, what about machining the block and head, bore it? Port it? Crank, rods, Pistons? I've heard of people using a 2.5 block or are they boring out a 7a/3b/aan and any other machining that would be recommended on the block? Is it cheaper/better to have the 7a head machined for the water manifold? What about valves? cams it seems like the 7a cams are the desirable ones to have?
I hope I'm not off line with questioning this but if I'm going to build a motor I would like to do it right the first time. I own a coupe that some company in Jersey built, not for me. I purchased it without a motor, I called them and was told it had a 650hp motor in it. 2.5 block, dahlback head, and big turbo that's all I was told no clue what happened to the engine but I would be ok with that kind of power. Building a strong reliable motor with as much hp as I can push out without having to continually tune and tweak if that is possible.

paradox11235

· #20 · Jun 4, 2014

2.5 eurovan motor is a taller block so you can get more displacement, but you gotta do internals. I believe the biggest you can go on a Aan/3b/7a is right around 2.3-2.4 liters. Bang for your buck is 20vt motor with forged rods, that should be good to 700 horsepower or so, from what I've heard anyways. 7a head is better because they see less abuse, but if you have a turbo head in good shape then that's fine. I wouldn't really bother too much with head work except bigger/undercut valves, and maybe some polishing. There's a really good thread somewhere here about porting the 20v head, and there's not a lot to gain. The 3b intake supposedly flows the best, then you'd probably want a good equal length tube header. 7a cams are slightly more aggressive and flow better up top, particularly with a big turbo.

The numbers I've heard for limiting factors in the stock motor are as follows:
Rods: 400 hp
Pistons: ~700+hp
Crank: don't think I've seen anyone break one from too much power
Head: 1000+
Crank thrust bearings: 1300

If you really want to go all out I'd do the stroker block since they're cheap, he pistons/ie rods, coated bearings, arp hardware all around, polished head with lightweight valve train and oversized and or undercut valves, custom manifolds.

For the power you mentioned I'd just do rods, bearings, arp hardware, and whatever you feel like doing for flow. Basically as long as the bottom end can handle it, the rest of the motor can be pushed. Head work just means running less boost for the same power.

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