ok how much would i benefit with a cutout right after the down pipe? my exhaust is 3.5 all the way just barely over the axle with a 3.5 spiral flow. would it be worth puttin a cut out right after the dp? if so how much?

 

46.84rwhp based on ALL that information you gave with your post.

 

 

ok *** what else you need to know?

 

I would start with the motor......

 

what do you have to know bout the motor to figure out if running a cut-out after my dp would make a noticable diffrence or not? just wondering if anyone ever dynoed back to back with exhaust then cut-out, and to see the results. on the other forums no one needed any other info! and people like 1982z28pieceofcrap is one of the reasons i quit posting over here! oh and please stay out if you dont have any usefull info!

sorry for the rant, and sorry to anyone else reading this post, i would still like to know.

 

The reason the turbine wheel spins is because there is a differential across the wheel. High to low. Post-turbine being the 'low' side. So make the low side as low as possible to induce flow. Run a large diameter down pipe/exhaust with a low restriction muffler and be done.

Or, unbolt your exhaust and see how it runs.


Edit: Well...... what did the other boards say?


-Scott.

 

Well if you had a 200 hp motor and were running 3.5 inch pipe and a straight threw muffler you wouldnt pick up anything. is that spiral flow a straight threw? if so even if your 500-600 hp you probably wouldnt pick up a whole lot. now if it is chambered of some sort i would deffently put in the cutout. But nobody can tell you how much power you would gain with no info posted about your car.

 

Your asking a blind question without any information. It's like saying, "how many hairs does a cat have".

I've personally seen right at 9-12rwhp from a stock catback to cutout on 3 of my vehicles, n/a and nitrous cars though.

What motor setup, turbo setup, power range, tranny, etc.

 

Not a good way to get people to answer your posts. Try being more descriptive with the motor. What heads/cam/c.i. you running? Tough to know how much air you would be pushing out without some info.

 

people that make coments like his i dont want to answer my post, i got some info over on ls1tech of some people that have tested back to back, but my setup is a lt1 filled with, cola 4340 forged 3.75" stroke crank, Eagle H-beam rods, JE .040 over pistons, 4 bolt splayed billet mains, LPE cnc heads that have been reworked by Yelvi, flow around 275 on the intake and 218 on the exhaust (LT1 castings). Also has head studs, cometic gaskets, Crower hydraulic lifters with the block modified to use them, had to mill the lifter bores slightly, 76mm turbo, kit is simular to the tti but most the problems fixed, huge intercooler with 3" piping, 3.5 dp and 3.5 all the way back with a spiral flow, or bullet (have one of each this is my delima), its a 6 speed, with a mcleod twin, s60 with 3.50 full spool, it just has a street tune on it now making bout 5-6 psi and spining my 335 nittos till bout 65mph. not sure on the power but it sure feels good!

 

Well, I know Justin, and his comments were light hearted and he was trying to point out the fact that you told us nothing about the setup.

Now, moving onto your combo, I may have missed it, but what cam you running? If you are running a mild cam, not sure how much power you will gain with a cutout versus the 3.5" DP, but the spool time should change with the cutout open.

 

How much higher you plan on turning it up(boost). I don't think you'll gain much at your power level with those muffler choices.

 

It will make a marginal difference with your street tune/setup. It will make a huge difference once the boost is turned up. Trust me, I know.