well i am having true dual built for me 88 camaro, umm its a t-5, 3.42s, 70s 350 truck block that is being bored next size over, zero decked ARP bolts installed and such, but whats going on/in it is;
induction- http://www.azspeed-marine.com/chvofuinsy.html
heads- http://www.compperformancegroupstore...ry_Code=VORTEC
headers- http://store.summitracing.com/partde...5&autoview=sku
cam/lifters- http://www.flatlanderracing.com/compcams-sbc01e.html (its the last one at the bottom in the green shaded area part #SK12-268-4)

now i now im going with true dual but should i go with 2.5 or 3in? i was told 3in before, but i wasnt going true dual then so now im thinking 2.5in, pros? cons?

and then cats, well its simply should i or not? i dont now a lot about them so any suggestions that that would be very welcomed.
thanks for the help.

 

I made 1K bhp using the stock 2.5" mid pipe and cat back on my C5. I think with a 350-383cid NA that a dual 2.5" exhaust system will support any hp goals you may have. I have a 91 Bird, I put it on my lift today to check out if I want to fab up some duals.....I came up with two options one would be to run 2 2.5" pipes close together and run them in the stock location or to run my dual cat setup into a single. But since the stock single (stick) appears to be barely 2.5" I am going to replace the stick between the cats to the muffler with a section of 3" or as large as I can fit to take advantage of running headers.

I don't think you need to run a dual 3" system unless you just want to say you have one. On my old 97 C5 I did Heads and Cam and TPIS LT headers....it put down 430/400 rear hp/tq.....and I retained the stock 2.5" plumbing....ran an 11.7 easy with that car.

 

ok cool, thank you. but what is the use for cats? is it just for sound?

 

Actually the Catalytic Converters are a Federal Emmission Standard.

What I found about cats is that they also really do about 70% of the muffling. When my 97 C5 (first C5) was Naturally Aspirated I tried a few variations to see what gave me the best performance.

Best performance was headers, off road mid pipe (catless) and straight pipes (no mufflers). But that was too obnoxious both inside and outside the vehicle. Then I went to Headers, and just mufflers (Magnaflow 4" rounds...check my sig pics) and that sounded badd *** but was still pretty loud. The next try was putting back on my mid pipe (with cats) and straight pipes (no mufflers) this was a good setup as the car had the smog equipment on, but the straight pipes made it sound better then the mufflers...with headers this was my favorite setup.

I am going to put on headers (Dyno Don's) with some C5 cats (smaller dimensions..higher flow) and straight pipes on this car. I expect it to perform and sound way better. Sticking a Flowmaster on a stock (anything) has close to no performance gain....it only sounds better. I just have to decide whether I want to run duals all the way back or merge them via a Y pipe into a new 3" stick over the axle. Since there are guys on here that have made over 400 rear hp/tq with a single 3" stick...I will probably go with that for simplicity and space.

I have settled on my build for this car (91 Formula) for the most part and it will be.

TPIS Miniram (HSR will not fit without cutting...FIRST doesn't appear to rev as high as I want).
Dyno Dons Headers
AFR 195 Heads, 1.6 RRs
Comp Xer 22x/22x 112-114lsa cam
2800 Stall Converter


I am doing the Mini and Headers first just to see what the difference is over stock...should be interesting.

 

Yes, cats are required by federal law on a street vehicle in all 50 states. They are the best as cleaning up the exhaust from your engine and reducing the fuel smell on you and your interior.

What are you doing for a y-pipe with those headers? The y-pipe for those 2460's is known to be not as good as the y-pipe that comes with the Hooker 2055's.

What are you doing for an induction system? An 88 Camaro base model would have TBI on it, and you're not going to get a TBI computer to run very well with a 224/230 camshaft in it.

 

wow...ok im dumb i thought cats meant something else other then the Catalytic Converters...but thank you.
kevin- actually im not sure how i ended up with 2460s...mayb bc of price but i dont know lol. and for the induction i am using the vortec system, 5.7L. the kit comes with a computer and everything i need. which would be better for true duels tho? 2055s or 2460s?
and i am running true duel 2.5" from headers back. i have seen it done with h and x pipe. correst me if im wrong but i need a h or x pipe bc it evens out the back pressure? or is it just for sound?

 

this is not entirely true, maybe in a certain application, but i added cats to my car and it didnt get noticeable quieter at all.

However, these were aftermarket high flow cats, not factory. When i had to gut my original cat after i bought the car because it clogged, it did make the car louder.

 

Yes aftermarket high flow cats like Random Tech and others will sound lounder because they don't muffle as much. I was making 430/400 rwhp through the C5 stock catalytic converters and straight pipes (no mufflers). It was much louder then having no cats and mufflers.