SStroked 410

I was talking to a friend today about my exhaust set up. And he said I might have too much back pressure from the stock cat back? Causing my car to not idle and stall?

I was planning on running my 1 7/8" Kooks race headers with QTP 3" electric dual cutout y-pipe into a stock cat back to keep it kinda quite when driving through town (cops). So when I race I can just flip a switch to open the dual cut outs.
what do you guys think... can I pull it off with the stocker and not have idle problems? I know I will need some good tuning with a cam as big as this 248/252 .610/.614 113lsa

maddboost

iTrader: (11)

Try using a SLP Dual-Dual Exhuast they work great for keeping quite and not choking the motor.

SStroked 410

but what about the stock cat back? Would it be too much back pressure

I think I might try the stocker but what could happen from too much back pressure?

Nickn20

SS catback? either way id say that putting a stock anything catback on there that restrictive would change your tuning completely, for example stock catback you would most likely detonate as oppose to uncapped, becuase of the restriction. get a good flowing catback like the magnaflow its not too loud..... or the SLP D/D SLP D/D will cost you about 20 rwhp or so closed, IMO I think dual cutouts are so loud I don't enjoy going WOT with them open, its just freaky, I mostly just like to listen to it idle with them open lol.

Worm

iTrader: (2)

You might wanna get some chambered mufflers. I dont think the car will have a problem idling, but it might detonate a little bit under 40%+ throttle. I've had my stock cat-back forever and I just have the weld-in tube mod with QTPs. The exhaust gases usually cool enough by the time they get to the mufflers it shouldn't affect things tooo much. No cats right?

SStroked 410

thanks for the info guys

I guess I will just try to pick up a dual/dual
I am not too worried about losing power with the cut outs closed since I will only race with them open

Pro Stock John

iTrader: (34)

It's not the backpressure that causes your idle to struggle, Autotap your IAC counts they are probably thru the roof. You want them to be in the 30 range to be like stock.

That cam is big but it should idle at 1000.

Jammer

iTrader: (1)

Not for nuttin but... I ran a cartek stage 2x package last year...had 427 rwhp and 396 TQ... through stock cat back and muffler. Did 20 runs on a track rental day. I gained absolutely nothing with my cut-out open. So my WS-6 cat back did not effect my traps with a 224/228 cam and 2x heads, headers and pully.
BUT THAT WAS A 346.

SStroked 410

I think it would be alittle different on this size of a motor... I cant see how you didnt gain anything with the cut out open with a stock cat back? I would think atleast 10-15rwhp

Got Me SOM

iTrader: (2)

WS6 exhaust is actually a pretty good exhaust system.

SStroked 410

update and question...

I now have the same headers 1 7/8 Kooks, gonna goto QTP 3" dual cut out y-pipe and then to a SLP dual/dual catback.
I know with this set up I will be ok with one tune for running with/without the cut outs open.

My question is
is there a 3" cat I can put in the I-pipe thats very free flowing that wont require me to have another tune set for when the cut outs are open and closed? I have a friend that will pass my smog but have to have atleast 1 cat

thanks