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Discussion Starter · #1 ·
hey, i was wondering how much difference there is in total power output and any other issues might be between the two butterfly,non turbo TB and turbo TB might be.

and in jims case, did you go with the 4kq manifold just for that TB or because your I/C plans or what?
having the plumbing setup like jims and mykes, seems like a ton of piping running everywhere. and how would you guys say that having all that piping affects performance and turbo lag. i don't imagine that once under boost you would notice it that much, but, on the other hand I've read in turbo books/articles that more bends is not good.

jim and myke seem to have about as much plumbing as you can get,but they both have #'s to prove they're fast.

this is just a topic i've wondered about since i first got into turbos and such.
soon i'll have pics of my intercooler (now finally completed) and KH intake mounted and the plumbing is about as short as it could ever get, unless my I/C outlet came up as far as javads. the i'd have about a foot of total pipage. :)
 

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Reasons behind moving the TB,

1. Makes for much better fuel rail access

2. Makes more room on the pass. side of the engine compartment.

3. You get rid of the funky inlet of the turbo manifolds, which to me just doesn't look like it flows all that well.

4. Makes more room on the pass. side of the engine compartment.

5. Makes more room on the pass. side of the engine compartment.

Bottom line, is you're going to have a large crossover pipe somewhere.

I personally don't buy the "you loose spoolup time with lots of pipes" Maybe on a stock car that can't breath worth a sh*t anyways, but not on a car with no cat, full 3" exhaust, header, 2.5" mandrel bent intake tubing, and well, my intercooler. I'll admit, I'm not the biggest fan of the big J bend before the TB, but to me it's better than having a sharp silicone 90 on there. I've driven my car with about 3' of tubing running strait from the turbo to the intake expecting a huge increase in response. Not the case. No difference at all. All I say is, if you've ever stood 15' behind a car with 300+ hp on the dyno, you'll know it's like being in a hurricane, I don't think people really know how much air motors pump out at full tilt. I think they picture themselves pressurizing the intake with a garage air hose and that since it's bigger and takes longer there, it must suck in the road.

Ok, rant off, this isn't aimed at you Derrek, I've argued about this in the past with people and I just don't buy it for cars like we drive.

Short piping does have it's place though, races where you may have to run a restrictor or something. Then you start trying to get every once of energy you can out of equal length headers, and other tricks that just aren't practical to us.

How would I do it ideally? Move the IC endtanks up, and make the TB at a better angle. The second one I already tried, and it just screwed up air distribution, so obviously Audi has done their homework on IM's.

It's one of those things people put to much though into, go find yourself a nice IC, and just install it. It's way more important to have a nice IC over short piping.
 

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Jim, thanks for writing the email I didn't feel like typing, I agree 100%.

Its one of those esoteric things that many turbo people freak out about that just really doesn't matter too much in practical use.

Make everything fit best you can, clean, securely, reliably, tidy it up, try to make it look somewhat factory, and run it. Practically speaking, getting the motor tuned properly is probably going to have the biggest effect over any of this stuff, that and the right components, right turbo, big IC, etc. If the crap is always breaking/melting/rubbing, that will shut your car down quicker than a little extra intake plumbing.
 

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Discussion Starter · #5 ·
hey guys, thanks for the input. i value your knowledge greatly.
my intake plumbing is planned out of simplicity, I really don't like the I/C sitting on the bumper like someguys have done, but, hey, to each his own. it's really a challenge to fit stuff behind the factory grille on my car.

and yeah, i've stood next to plenty of cars on the dyno (there is one about 500 feet from my dad's shop) and i was there when a guy ran his 440 twin turbo 73 charger, man, talk about a racket. i couldn't hear for a bit after hearing the turbos spooling up on that thing. and it made 820hp to boot and he didn't ring it out to 6500 rpm like when he races. he shut it down at 5200 on the dyno, so he still had more to go. the print out showed his power climbing pretty fast then drop right off when he shut down. pretty impressive for a car with only 6 psi and no intercoolers. plus he runs 7.20's at the strip.....what a rush that must be.

:)
 

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Good topic Derrek.

I was just about to bring this up. I really like you setup Jimbo. I think it looks super clean. Manderal Aluminum isn't cheap though. That intake looks like Benji's lined up :) It such a rad setup for a big IC.

I want to expand upon your "changing the TB location" Ideas.

Now keep in mind that my Pops just got a 280 AMP Spoolgun im droolin to use, but anyone everthing of bringin the IM over the top of the valve cover? I know the volume of the IM would increase, but you would get a TB that is pointed down in the right spot. Sure it would be a pain the the butt to have to access a Valve cover, but i was thinking of making things easier but making the IM a 2 piece.

Aw probly more work that its worth.

Thanks for that Rant Jim, It make my mind work.

Maybe i'll strum up a MS pic

Hank
 

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Discussion Starter · #8 ·
one day i'd like to toy with an intake that has individual TB's and runners for each cylinder. it sounds a good idea if ever there was one :wink: . naw, just kiddin' i know they're already used on plenty of high performance cars. I think it might be better suited to an N/A application, but i'm still curious. i also would like to see how the 10v responds to shorter runners.
 

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Honestly, I question whether the 10v has a problem with the intake, the 20v head I just had flowed made identical #'s with and w/o the 7A manifold attached, my guess is that the 10v is the same way. Unless you seriously increase the flow through a 10v, I'd say the IM is fine the way it is.
 

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I'd agree with Javad on this one. I've thought about ITB's also, but they really aren't necessary on a turbo car. They mostly come into play on NA motors with wild cams. The ITB's keep the intake pulses out of the other runners. But they would be cool! Someday when I get bored and actually have a TIG welder I'll probably brew one up.

If you were to make a custom IM, Definitely use two pieces, the last thing you want to be doing is having to remove the entire IM just to get to the injectors, or head. Once you get a header on there, you'll know what I mean.

Oh yea, for the intake pipes, if you're like me, cheap, just use plain steal. I got some 18 ga. U bends from Summit, welded them with a little 110v Mig, ground down the welds and coated them inside and out with POR-15. So far so good.
 

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Thats what i did. For 12.99 a U, you can't beat it. Im not familiar with the paint you used though...just an anti rust? WHats out of control is the price of manderal SS 3'' bends. I nearly had to take out a lone to make a DP. :frustrated: Aw oh well.

Hank
 

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Sorry so late to find this post. (I found it google search my name DOH) I used mild steel mandrel bends. My 5000 had almost no plumbing very short there is a lot more in my 90 since the intercooler is so much bigger. The funny thing I haven't noticed any change in spool time at all?? Maybe cause I still have the heavy flywheel or something...
HTH
 

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so our best bet for a throttle body is the 7A or VR6? what are the differences between them? the v6 audi one is the one that seems "filled in" where as the ng/7a one's are nice and big. anyone have a pic of the vr6 tb?
 

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I have a VR6 throttle body on the shelf it's huge well good size anyways bigger than the V6 audi's way bigger than the NG/7A. Hey don't spend to much time online don't want to hear your in the dog house like adam or something.
 

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Cool, this discussion has motivated me to change my IC setup. I currently have a URQ IC in the stock location on my 4kq....not much airflow...but I've been reluctant to go with a front mount because of the lengthy plumbing....I should probably reconsider..!?
 

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Yes, the VR6 is a single plate throttle body using an almost-square, slightly rectangular flange. The throttle plate measures real close to 65mm. The housing is kind of... crooked. This is so that the throttle plate doesn't need that wedge-restrictor to smooth out airflow at small throttle inputs. The inlet to the VR6 throttle is nice and round, easy to get a hose on there.

The 7A/NG throttle body is the progressive twin-plate design with a 38mm primary and a 52mm secondary... which together equal the area of a 64mm single plate. Naturally there's a little loss due to the thickness of the throttle plates and the shaft in which they reside, but the point is that they are comparable in size to the VR6 unit. Which you use is more a personal preferance than anything else.

There's one throttle I have been kind of toying with - the 80-83 turbo used a progressive 2 plate throttle, but what is special about it is that the flange where the intake boot meets up is a separate piece. This would make it easy to A)weld on intake piping, fixing the possibility of blown-off hoses or poor seal at high boost pressure and B) put the throttle itself in a mill and enlarge the secondary, then of course machine a new throttle plate. Of course this is academic - how much throttle body do we really need? Wouldn't the turbo outlet be the most restrictive point in most of our intake tracts?

Want to see a scary throttle? Check the twin-plate throttle on the later 4.2 32vs - 50mm primary, 70mm secondary. Also, other OEM big throttles (for you junkyard dogs like me) - Infinity Q45: 85mm single, Alfa Romeo V6 65mm single, Jaguar XJ6 65mm single, Mercedes V8s (from the 80s) 65mm single (IIRC, its been a while). Those Merc's have pretty nice oil coolers too. I digress!

Continued Digression: the Audi twin-plate throttle has the same bolt pattern as many carburetors from the 70s, including the awesome Weber 32/36 DGV. The very same bolt pattern can be found on many foreign and domestic cars all the way back to the 20s! You know, the good old days of an 8 liter V12 with a tiny 1-barrel carb :)

Ok I'm done.
 
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