Any gains with shorty headers and Twin turbos?

[Whorable MPG1975]

Looking at twin turbo kits and was wondering if the shorty headers would work well with them instead of the stock manifolds? I was thinking my 1st wave of mods being an after cat exhaust upgrade and shorty headers than later putting the turbo's on. The final push would be a matching cam. Who has done this?

"Feel free to chime in if the designers ill-advice this!"

[Z_Rocks]

After watching this video, I learned more about back pressure and how it can be solved. http://www.phastekperformance.com/20...ders-s/324.htm
So, I'm sure there will be more benefit to having shortys before turbos and a free flowing exhaust after the turbo. This will really help boosting the turbo faster. Couple of points come up, but you should really talk to the turbo kit vendor to get the answer.

a) Can Shortys handle the weight of the turbos? Remember the heavy turbos are mounted to the manifold and the manifold is strong. Most of these shortys will crack and/or break due to heat and the weight and bouncing.

b) the TT kits are designed to hookup to the manifold where it leaves off. Your shortys must be ending the exact position as stock manifold.

If you can't get a guaranteed solution to the manifold issue, I'd stay with stock, but get a 3" exhaust right after the turbo. This way the hot side releases fast and turbos will spool quicker and keeping them cooler.

There three good TT kits out there, call them up and see what they say. I'll bet you they'll say leave the stock manifold alone.

Oh btw, do the TT and exhaust all at the same time, makes your life easier.
Good luck.

[AdamCzap]

Slapping on a 3" exhaust AFTER the turbos will do just like Z_Rocks says. My car picked up a ridiculous 27rwhp going from a restricted airflow to unrestricted (via my exhaust cutouts). I have youtube videos of back to back dyno runs closed vs. open:

dumps closed, stock exhaust:
dumps open, "free flowing" exhaust:

[Z_Rocks]

Originally Posted by AdamCzap

Slapping on a 3" exhaust AFTER the turbos will do just like Z_Rocks says. My car picked up a ridiculous 27rwhp going from a restricted airflow to unrestricted (via my exhaust cutouts). I have youtube videos of back to back dyno runs closed vs. open:

dumps closed, stock exhaust:
dumps open, "free flowing" exhaust:

Hey Adam, how is the car running? I bet with the cooler air, you're getting more boost now.

When the cutouts are open, does it get loud inside of the car? How much were those cutouts $$$? I liked the opening/closing motors but weren't they expensive? Almost cost of full exhaust?

[SRT10KLLR]

Originally Posted by Z_Rocks

Hey Adam, how is the car running? I bet with the cooler air, you're getting more boost now.

When the cutouts are open, does it get loud inside of the car? How much were those cutouts $$$? I liked the opening/closing motors but weren't they expensive? Almost cost of full exhaust?

I'm pretty sure his boost will not go up because it i regulated by his waste gate and/or boost controller. But, his hp might go up as the cooler air is denser and the intake air charge temp will be lower.

[Z_Rocks]

Originally Posted by SRT10KLLR

I'm pretty sure his boost will not go up because it i regulated by his waste gate and/or boost controller. But, his hp might go up as the cooler air is denser and the intake air charge temp will be lower.

You're right, mentally I was thinking more power, but I wrote more boost
I love turbos, especially during cooler weather!

[AdamCzap]

Originally Posted by Z_Rocks

Hey Adam, how is the car running? I bet with the cooler air, you're getting more boost now.

When the cutouts are open, does it get loud inside of the car? How much were those cutouts $$$? I liked the opening/closing motors but weren't they expensive? Almost cost of full exhaust?

The car is running awesome. The noweeds.net diverters are what I have. I think I paid $900, which is expensive, but the quality is top notch and definitely better than QTP's cutouts. And no, don't even think about listening to your radio or having a phone conversation in the car with them open .

My current problem is that my rear tires need replacing. I have 23k miles on them and the wear line is getting down to the limit.

[AdamCzap]

I occured to me that I never answered the question in the OP. I asked Hellion about getting shorty headers when I installed my kit, and they said you could do it and it would fit, but you would NOT get any power gains. The big 3 system builders for TT all made them to work with stock manifolds. You would, however, benefit from a 3" exhaust in a big way as my dyno videos show.

[Whorable MPG1975]

Nice numbers Adam! My L99 is going to do the same thing one day!

I was planning on doing the exhaust cut outs too, glad to see it picked up some horsepower too! I can't wait to do that on the 75' I got (with matching Mad Max style switch on the shifter, brar har har).

What system are you using after the turbo's than? I am planning on one of the big 3 TT kits out there right now. It is hard to beat a good cast iron exhaust manifold for strength, thats for sure. Hmmm, better use the money on a cam than.

The wife won't understand at first...

[Whorable MPG1975]

... and was hoping the vendor's would jump in...

[xxlbeerz]

I'd rather hang a turbo off the cast part due to heat/weight.

[speedster]

It is very true about the restriction with the exhaust especially after the turbos. Many people put on great kits and then kill a good percentage of power with insufficient exhaust. On one particular high HP turbo motor (not mine) it pretty much put a ceiling on the motor at 1,500 HP. Removing the exhaust let it climb to roughly 2,000 HP. This is an extreme example, but it shows you how severe an exhaust restriction can be.

[AdamCzap]

Originally Posted by Whorable MPG1975

What system are you using after the turbo's than?

stock exhaust system. it's restrictive, but when i'm not standing on the gas pedal it plays nice with the neighbors. been thinking about a 3" though...