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7At capabilities

Posted: Thu Jun 25, 2015 2:30 pm
by type85
Ok, I have some questions for the hardcore 20VT crowd:
For my 4000q racecar/track car project: I have a 7A that I'm "freshening up", 3B intake, 034 1C EFI (running E85) AND a K26/GT28RS (not purchased yet) on a "log" manifold, intercooler yet to be determined.
I know the 7A rods can't handle a ton of torque, what can I expect power/torque wise for a track car running E85 only (stock 10:1 comp), max boost?? I can also run water inj. if need be.
I'm looking for good torque and fast throttle response, as close to a N/A engine as possible, the car should weight about 2400bls. dry..

thanks

Dan

Re: 7At capabilities

Posted: Thu Jun 25, 2015 4:22 pm
by Mcstiff
I'd skip the "log" manifold, or at least stay IWG.

Here's my 7at thread for the CQ I bought from Nate@034. It made 180WHP on their dyno with no intercooler and had a very linear power delivery.

Re: 7At capabilities

Posted: Thu Jun 25, 2015 6:04 pm
by type85
Mcstiff wrote:I'd skip the "log" manifold, or at least stay IWG.

Here's my 7at thread for the CQ I bought from Nate@034. It made 180WHP on their dyno with no intercooler and had a very linear power delivery.


180whp=" 225 crank hp?

I've got the stock 3B manifold and k24:

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Re: 7At capabilities

Posted: Thu Jun 25, 2015 9:16 pm
by Mcstiff
Ok, stock manifold, cool.

Difficult to estimate CHP but something like that.

I'm currently running, well it's been parked for a while for a clutch and stuff, an H1C/HX35 @ 15psi on E85 and a stock 7a. Guessing WHP is high 200s but need to get it on a dyno. It probably does not give much up to the T3-60 but full boost comes later.

Re: 7At capabilities

Posted: Fri Jun 26, 2015 5:30 pm
by type85
The goal is to get a 10:1 power to weight ratio, I figure the car will weigh about 2,800lbs. with fuel and driver, so I'd need to see 280whp. wich by my calculations would be close to 350 crank hp.
Question is, is that possible with a stock 7A, EFI and E85?

Re: 7At capabilities

Posted: Fri Jun 26, 2015 5:39 pm
by PRY4SNO
If you have standalone, you should be able to tune the boost onset and prevent any big torque spikes that typically noodles the rods.

Re: 7At capabilities

Posted: Fri Jun 26, 2015 5:48 pm
by type85
PRY4SNO wrote:If you have standalone, you should be able to tune the boost onset and prevent any big torque spikes that typically noodles the rods.


I have an 034 "1C" ECU, the only available driver is used for idle control. I was going to run an Innovate stand alone boost controller.
I have to figure out what size and where to put the intercooler, space is pretty limited....

http://www.innovatemotorsports.com/xcart/product.php?productid=16351&cat=276&page=1

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Re: 7At capabilities

Posted: Fri Jun 26, 2015 9:38 pm
by deaner
Have you read through this build?

http://www.motorgeek.com/viewtopic.php?f=6&t=36744

Put out some impressive figures for what it is. Want to say he ran an 11.7 or something like that, in a coupe. Puts him over 300 I reckon?

Re: 7At capabilities

Posted: Sun Jun 28, 2015 5:00 pm
by SEStone
Pavel's run up to 20psi on his car, at which point it was basically dead equal with mine running a 3B-piston built 2.2L with a GT30R. It's done a track day with the boost turned down to 12 or 14psi, at which point it was plenty fast and very linear. He is running either stacked MLS gaskets or the 034 compression dropping gasket.

Re: 7At capabilities

Posted: Sun Jun 28, 2015 5:06 pm
by type85
SEStone wrote:Pavel's run up to 20psi on his car, at which point it was basically dead equal with mine running a 3B-piston built 2.2L with a GT30R. It's done a track day with the boost turned down to 12 or 14psi, at which point it was plenty fast and very linear. He is running either stacked MLS gaskets or the 034 compression dropping gasket.


So my question is: same 1C ECU, keep stock comp. 10:1, run it on E85 only with a K26/GT28RS, would I be able to get those power levels?

Re: 7At capabilities

Posted: Sun Jun 28, 2015 11:39 pm
by SEStone
type85 wrote:
SEStone wrote:Pavel's run up to 20psi on his car, at which point it was basically dead equal with mine running a 3B-piston built 2.2L with a GT30R. It's done a track day with the boost turned down to 12 or 14psi, at which point it was plenty fast and very linear. He is running either stacked MLS gaskets or the 034 compression dropping gasket.


So my question is: same 1C ECU, keep stock comp. 10:1, run it on E85 only with a K26/GT28RS, would I be able to get those power levels?


He's running a Ic as well, works great but he's had some annoying issues related to the distributor ignition--random cuts if the hall sender isn't working well, etc.. I would try to drop the compression. It may live with the higher compression and good fuel, but you put a lot more stress on the pistons and rods running the extra compression even without detonation for almost no payoff when running at the track with a little turbo like that.

Also, he is running a fairly large turbo...Holset something. It's very responsive for the size, much moreso than my GT30R, and he is likely making the power you're looking for at relatively low boost...<20psi vs. the 20+ you'd have to run those smaller turbos at to make 350whp. Having driven his car I would be totally comfortable with the response and powerband on the track.

Re: 7At capabilities

Posted: Mon Jun 29, 2015 2:39 am
by type85
Thanks for the info, I got the option of doing the comp reducing gasket.
Do you think the GT2871R with the stock 3B manifold is a good choice, or should I look at other manifolds, I know the Motorgeek guys had good success with the Ebay "log" manifold....

Re: 7At capabilities

Posted: Mon Jun 29, 2015 10:30 am
by PRY4SNO
You should be fine for the time being. I've read/heard a few times that the limit of the OE manifold is about mid300s at the wheels. Basically to the limit of a billet k26 or similar.

Here's some good info:

http://forums.quattroworld.com/s4s6/msgs/196904.phtml

Re: 7At capabilities

Posted: Mon Jun 29, 2015 11:23 am
by deaner
It's an HY35 on Pavels car. I've been daydreaming about the same turbo for some time.

http://www.motorgeek.com/viewtopic.php?f=4&t=70713
Buy this manifold and a $200 HY35 from goldfarb and you're into the guts of the system for $400.

If I didn't have more pressing parts purchases, Hans's manifold would be mine and it'd be sitting on a shelf next to an HY35.... Just waiting lol.

Re: 7At capabilities

Posted: Mon Jun 29, 2015 11:32 am
by dana
i ran the hy35 on my car and liked it a lot. I never tracked it, but it did seem pretty responsive for being as big as it is.

Re: 7At capabilities

Posted: Mon Jun 29, 2015 11:47 am
by Mcstiff
deaner wrote:It's an HY35 on Pavels car. I've been daydreaming about the same turbo for some time.

http://www.motorgeek.com/viewtopic.php?f=4&t=70713
Buy this manifold and a $200 HY35 from goldfarb and you're into the guts of the system for $400.

If I didn't have more pressing parts purchases, Hans's manifold would be mine and it'd be sitting on a shelf next to an HY35.... Just waiting lol.



I don't want to be too mean about it but the 034 Log with external WG is a pain. Hank dealt with the brunt of the frustration for me, and I'm pretty sure he would not want to do it again ;) It is a bit of a PITA to install/remove when necessary.

Here's what he did:
Hank wrote:That manifold is a piece of shit to deal with in a small chassis car. It is an eternal struggle to manage clearance to the frame rail, tie rod and transmission. Thank heaven it is out of my life forever.

Hank


Mcstiff wrote:So here is an update!

Hank had to do quite a bit of effing around to get the 3" downpipe to clear the chassis, subframe, transmission and still connect to the downpipe! But he managed to figure out a solution:

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I may shave a bit off a fin on the case and make a bit more space on the chassis but everything bolts up without any major interference!

I need to hunt down some oil lines (-3&10 or -4&12) and finish wiring (wanted to make sure everything fit) then I can fire it up!

Re: 7At capabilities

Posted: Mon Jun 29, 2015 2:18 pm
by type85
This was the Ebay log manifold I was referring to:

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Re: 7At capabilities

Posted: Mon Jun 29, 2015 3:29 pm
by audifreakjim
Dan, I think you have a solid plan. I would use that ebay manifold over the stock 3b. That turbo with E85 and ~15 psi will be a riot on the track. Keep it out of detonation and high revs and the bottom end should be fine.

Re: 7At capabilities

Posted: Mon Jun 29, 2015 3:55 pm
by type85
audifreakjim wrote:Dan, I think you have a solid plan. I would use that ebay manifold over the stock 3b. That turbo with E85 and ~15 psi will be a riot on the track. Keep it out of detonation and high revs and the bottom end should be fine.


Thanks big fella!!
It's gotta be ready by Nov. 21st: http://www.motorsportreg.com/events/socal-audi-driving-school-buttonwillow-raceway-club-na-southern-california-760216#.VZGwiflVhBc

Re: 7At capabilities

Posted: Mon Jun 29, 2015 5:44 pm
by audifreakjim
Sweet! I'll be there.