matt3383

iTrader: (3)

Alright car specs are:

228/230 cam
bolt ons
n20

Car puts down roughly 400rwhp 380 tq no spray
Have yet to have the car dynoed on spray however setup is
HSW plate kit
150 HP jets

I read the stickies and in one of them it stated above 500 3 inch might be better. Now since im only going to be above the 500 mark for say 11 seconds, will not having 3 inch be a restriction on the car? Or would the impact of having 3 inch when not spraying be more?

5.slow99

its not really going to make a huge diff except when your on the street its just the back pressure build up of having 500 is big and you might feel maybe a tad of dragging when you WOT, but with 3 youll be able to rev up a little faster

matt3383

iTrader: (3)

Yeah kinda what I was thinking. Not really worth it for the money. 10 bottles filled or 3 inch exhaust hehe. ( guessing 500 bucks from TSP )

5.slow99

i think youll find more intrest in filling up 10 bottles LOL

teke184

iTrader: (5)

i assume you're talking about a true duals setup??

cause if you're running a single 2.5" exhaust


but yeah, you may gain a little in peak power, but not enough to warrant the $$ for the swap.
best thing would be to keep an eye out for a really cheap used set.

other option is to run 3" off the collectors into some cutouts, then the rest is 2.5"

minimal expense, but you can benefit from 3" at the track.

matt3383

iTrader: (3)

Yeah its a x piped dual system.

I know TSP sells a 3 inch system, which is why I was asking. The car is lowered so I know 3 inch is going to be even more of a pita driving around than my 2.5 is now. I just wasnt sure if the current setup was going to be a huge restriction, or enough for me to warrant looking into a 3 inch setup.

MeangreenHD

iTrader: (6)

oh boy he said the "back pressure" word............

theory would say you should gain a few ponies up top and loose a few down low. an ls1 especially with a cam doesnt make any power down low and your never gonna be in those rpms at the track anyway.

matt3383

iTrader: (3)

hehe. well you said it better than I can. Basically it sounds like a few HPs here a few gone there = spend money on bottle fills instead.

bluehawk2

iTrader: (74)

dual 2.5's is still better than a single 3'' I pipe.

NC98Z

iTrader: (1)

Throw you an 3" electric cutout on it. That will get you 10+rwhp at WOT and get rid of your back pressure at the same time.

matt3383

iTrader: (3)

How can I throw a 3 inch on a 2.5 inch dual setup?

bluehawk2

iTrader: (74)

I'm gonna say he aint got much back pressure as it is........................I ran a bunch with a 100 shot H/c and I didn't see any difference when I uncapped the cutout. I have magnaflow.

teke184

iTrader: (5)

"its not really going to make a huge diff except when your on the street its just the back pressure build up of having 500 is big and you might feel maybe a tad of dragging when you WOT, but with 3 youll be able to rev up a little faster"

i'm curious what you mean by "dragging" at WOT?

2.5" is more than sufficient to allow 500hp to breath. you'll never feel the 10hp difference.

backpressure is minimal assuming you have halfway decent mufflers.


and how the hell would it make a difference more on the street? the power to be gained by going to a dual 3" setup would be all top end. how much time do you spend around town >5000rpms?


only reason i have dual 3" is because i found a killer deal on the parts...1/2 price was too much to save compared to the small ground clearnce i was going to sacrifice (i'm not lowered).
besides the mufflers are what scrape...not the pipes. so going 2.5" wouldn't have mattered much for me.