Hey guy's I got a 89 Formula 305TPI and want to completely upgrade the whole exhaust system on a budget of maybe $500. I think I may be able to get some headers for like $80 too. But What would you say would be my best bang for the buck. I'm talking 3inch all the way through, Headers+y-pipe+highflowcat+catback. I'm hoping to add about 20-30hp. I plan on doing this mod after I get a V6 3.43 rear end in first though. What do you guys reccomend for a complete system.

 

20-30hp is a big stretch dude.

Expect 15hp at the most IMO.

 

Which car is this going on? If you are putting the entire exhaust from headers all the way back I would say 30 hp actually seems a bit conservative. The stock exhaust is pretty damn restrictive, especially on the L03.

 

Flowtech headers and y-pipe, Catco Cat, and Dynomax cat-back. You should be under your budget limit, however, this doesn't include good bolts and gaskets. Don't be cheap on these parts, otherwise you'll be under the hood everyweek tightening things down.

You might me able to find another brand of headers for about the same price, but Flowtech was the first one to pop in my mind.

-The Gunny

 

Where did "LO3" come in? He said "TPI".

Flowtechs are 1-1/2" primaries, 2-1/2" y-pipe at the cat. Might be okay for a relatively-stock 305, but may not be any improvement over the stock exhaust. $211. Might be better off with Hedman shorties w/1-5/8" primaries ($120) & y-pipe ($100) - as I understand it the y-pipe is as small as 2-1/2", but mates to a 3" cat. If you need A.I.R. on the headers and want 1-5/8" primaries, you'd be better off moving up to Hooker 2055's - $360.

Catco direct-fit high-flow cat, $120. Don't go thinking a universal cat will save you money - by the time you get it hooked up to the rest of the system, it will have cost you more than $120.

Flowmaster American Thunder cat-back is $325, Hooker slightly less at $265. Either would be a good system. I'm having difficulty getting the application chart on the Dynomax site, but the only listing Summit has for them is 2-1/2" I-pipe - again, probably more restrictive than your stock system.

Those $80 headers will probably cost you more than buying a set new. Most likely, you'll have to have a shop hook them up to your exhaust system (even if it's your new exhaust system), which will probably cost you more than buying a set which is made to go to the cat.

I doubt you're going to get there with $500. Especially if the emissions people look under the hood for A.I.R. to the headers.

 

Well I'm not worried too much bout emmissions. I'm moving to florida in August to finish up my degree at Saint Leo University. How come nobody is saying FLowmaster is a good Cat back system. I've heared from alot of people that it is the only true 3" setup all the way through. Where dynomax shirnks up at the muffler.

 

Well, I can't speak about the possible problems with universal cats, but I think any system is better than the stock set up. According to Jegs website, there is a 3" Dynomax system. At least it better be, because I ordered it 4 days ago.

So you're looking at $175 for the cat-back, $236 for the headers and y-pipe, and $120 for the Carsound direct fit cat. Which totals $531. Of course you could still spend $50 for aluminum gaskets and Grade 8 bolts.

-The Gunny

 

I didn't see the TPI, I only read his sig. I'm pretty sure the non G92 305 cars had the same exhaust as the L03, but I'm not absolutely sure. Anyways, everything you said was once again very true. Five7kid knows his stuff when it comes to exhaust. I think of you as the Hooker header master, lol.

 

Exhaust was based on the engine (LB9, LO3, etc.), except dual cats starting in '89 w/G92.

A complete aftermarket exhaust is hard to do on our cars for $500. If you skip anything, skip the cat.

 

Five7 mentioned Flowmaster, personally I would get the Hooker one for $70 cheaper. It's 3" all the way back.
Sound clip in sig, but if you want a Flow get a flow.