3l turbo bottle neck???

[BurritaSVT]

Personally, if your running the NPG kit, I think the bottleneck is the FMIC and not whether your running a 2.5" or 3" catback.

Actually the bottle neck is the exhaust the exact same size setup I did here not one thing different made 40whp more at the same boost level if you look at the dyno pulls the intercooler is not the culprit it keeps the power throughout the rpms band. 355whp 360wtq moving over 43 lbs/min is no way suffering from air getting the motor. I was running 10 psi whcih should meake 375whp on the same intercooler IAT stayed lower than 110 on a 100 degree day. It seams most people concentrate way to much on the intercooler size and less on what the exhaust is setup as. You can put in as much air as you like but rememeber you have superheated gases expanding which take more area and volume to release then what piping you put it in with. You intake piping should not be larger than your exhaust piping simple math. The intercooler we sell the first one has 5.25" sq/in of area and the second one has 7" sq/in (425hp/43lbsmin) and I have another one that has 11" that will do (600hp/59lbs/min) the reason factory setup gain more power when they swap intercooler is because the turbo they use are so inefficent and small for the setup. So that when you push these small snails hard you need more are on the cooling surface (not the air flow) to draw down the temps which give more power for the buck. We don't suffer heat issues at all our turbo stay well within there 70% range ask anyone here of their datalogs none of their setup go over 110 degrees before the TB IAT even Vegas BADSVT can show you logs of that.

I would be willing to bet some money that I could go over 400whp on the 26" x 6.5" x 3.5" core the one we used on our last test. If the car was mine I would have most definitly turned up the boost to make 400whp on a stock block.

Bad SVT will go back to the dyno to prove the gains I am sure he will pick up 15-20whp with the exhaust but he also has a CAT too so I think it will put him at 335-340whp because of the CAT. We shall see I wish he would have just dropped the downpipe at the dyno to see. Joey

 

[BAD SVT]

Personally, if your running the NPG kit, I think the bottleneck is the FMIC and not whether your running a 2.5" or 3" catback.

i dunno. i've got the larger one. my IATs were low when i dynoed. it was an airconditioned shop. trust me when i say this. if u drove this car b4 and after this exhaust upgrade, u would have to be either a complete idiot or not living not to notice the difference that was made. i'm not sure if ryanblacksvt did his dyno yet. but am willing to bet if he stays at the same boost and runs the car on the dyno again, even with his much larger intercooler, he doesnt get more than 10hp.

Bad SVT will go back to the dyno to prove the gains I am sure he will pick up 15-20whp with the exhaust but he also has a CAT too so I think it will put him at 335-340whp because of the CAT. We shall see I wish he would have just dropped the downpipe at the dyno to see. Joey

i know han. wouldve been hecka loud tho. at that point, i didnt even know my exhaust was causing problems.

 

[2000ZxT]

I don't see how this exhaust size issue is being argued. The best setup for a turbo? Absolutely nothing after the turbine.

The bigger the better no matter what HP your going for, this is not a N/A car.

 

[SicSE]

*waits patiently*

 

[Harrry]

*waits patiently*

This newbie has the right idea :laugh:

 

[SicSE]

This newbie has the right idea :laugh:

You're slippin' Harrry... not even the slightest rebut to 2000ZxT's post. :nonono: :laugh:

 

[Harrry]

You're slippin' Harrry... not even the slightest rebut to 2000ZxT's post. :nonono: :laugh:

lol....i knew you were waiting for me. Of the irony :laugh:

 

[gotapex]

Agreed. This is why a larger downpipe is often one of the first performance mods that people do to a factory-turbo'd car. What good is an adequately sized cat-back exhaust if there's a bottleneck betwen the turbo & CAT? Not very much good.

Exactly. Also, exhaust gasses cool and condense as they get further and further downstream. There's definitely less need for muffler end diameter than downpipe diameter.

I would be willing to bet some money that I could go over 400whp on the 26" x 6.5" x 3.5" core the one we used on our last test. If the car was mine I would have most definitly turned up the boost to make 400whp on a stock block.

I wouldn't bet against you.


BTW, I definitely noticed a difference between 2.5" dual and 3" dual, even with a very short exhaust.

 

[morbid]

So with the ADC kit, it has a 2.5" SS down pipe that is about 3' long. Do you think there could be gains from going with a 3" down pipe? Just theoretically... I'm not sure about the clearance with that. But.. there's always ways to do that... like dual pipes (ala Joey's design), or an oval pipe under the tranny.

 

[BurritaSVT]

So with the ADC kit, it has a 2.5" SS down pipe that is about 3' long. Do you think there could be gains from going with a 3" down pipe? Just theoretically... I'm not sure about the clearance with that. But.. there's always ways to do that... like dual pipes (ala Joey's design), or an oval pipe under the tranny.

We change our design on the SS piping we did 2.5" under the tranny due to fabrication cost was 10% more than now and we still made 350whp at 8.5 psi so I am guessing you could maybe pick up a few ponies if any but seriousily the car at 350whp was hard to control at this level. joey

 

[RawBurt]

FWIW, my old SVT (high mileage 2.5L) put down 295 fwhp @ 11psi on STOCK exhaust piping

 

[SicSE]

FWIW, my old SVT (high mileage 2.5L) put down 295 fwhp @ 11psi on STOCK exhaust piping

At 11psi, I'd bet you were losing at least 10hp over even just a decent 2.5" setup.

I'm really surprised you guys boost these things without upgrading the exhaust.

 

[Harrry]

FWIW, my old SVT (high mileage 2.5L) put down 295 fwhp @ 11psi on STOCK exhaust piping

So did you modify any thing on the exhaust? headers? main Cat? resonators? mufflers?

 

[RawBurt]

The piping was stock.
MSDS jet hot coated headers, magnaflow mufflers / resonator, no main cat with npg piping.

 

[BAD SVT]

well I already had put a 2.5" trubendz exhaust on my car, I was kinda thinking ahead as I knew about the turbo kit before I got it. will see what it puts down on the 27th.

keep us updated on that bryan

At 11psi, I'd bet you were losing at least 10hp over even just a decent 2.5" setup.

I'm really surprised you guys boost these things without upgrading the exhaust.

:laugh: am not sure why. it seems the stock exhaust has always been able to handle anything thrown at it. looks like now we're starting to get a very good sense of what its limits are.

 

[BrApple]

keep us updated on that brian

will do .... and fixed that


and according to joey the maf on my car is reading 40#/min which he said would be around 400 hp ... so account for 18% driveterrain power lose and I should be around 330 @ 8 psi ...

 

[BAD SVT]

will do .... and fixed that


and according to joey the maf on my car is reading 40#/min which he said would be around 400 hp ... so account for 18% driveterrain power lose and I should be around 330 @ 8 psi ...

:laugh: sorry, somehow i missed that. u guys are fortunate tho. the dry and hot air out here wont let me get the sorta numbers that u guys in the east and south get. its all good tho. i'm not all that hung up on dyno numbers. but 330 @ 8lbs? wow. thats around what i expect to get at 10psi.

 

[gotapex]

:laugh: sorry, somehow i missed that. u guys are fortunate tho. the dry and hot air out here wont let me get the sorta numbers that u guys in the east and south get. its all good tho. i'm not all that hung up on dyno numbers. but 330 @ 8lbs? wow. thats around what i expect to get at 10psi.

Dynos vary quite a bit from machine to machine.

http://www.turbomagazine.com/tech/0306tur_dynodash/

 

[Harrry]

The piping was stock.
MSDS jet hot coated headers, magnaflow mufflers / resonator, no main cat with npg piping.

The only thing stock was the 3 ft of tube you had. :shrug: The rest was opened up. Size of pipe vs flow is tooo completely different things.

You can still flow 300cfm from a 2 1/2 pipe with a free flow mufflers/resonators like you had.

And flow 300cfms with a 3 inch exhaust having a stock like set up with 3 cats crappy y-pipe resonator and stock mufflers.

See what i mean

 

[BAD SVT]

At 11psi, I'd bet you were losing at least 10hp over even just a decent 2.5" setup.

I'm really surprised you guys boost these things without upgrading the exhaust.

besides, only about a year ago, u could probably count on one hand how many boosted cars we had on here. now, there are quite a few of us with FI, thanx to joey(burritasvt). so naturally, knowlege of the way these cars respond to forced air will only get better.