I was wondering if I should get a Cat Back Exhaust system or headers first. I don't have that much money, so I really can't afford both. Which would be best?

Also, my setup must be emmisions legal.

Thanks,
Tony

 

I guess with money being an issue I would go for the catback first and headers second. Think you would be happier with the catback.

 

I think having a "plan" is a good idea, and whatever you do, do it right the first time (and save yourself some money and time). I'd go with the Hooker catback first, then eventually a Catco hi-flow cat (or if emmissions isn't a problem, perhaps a straight pipe), and Hooker headers. This system is high flowing and aggressive sounding--at least at WOT.

JamesC

 

Why not get both as you can pay for them, and then when you have all the parts, do it all at once. Thats what I did... I bought the headers, then the Y-pipe, then the catback, then tips... then over one weekend, me and my cousin installed the whole system all at once.

 

What would be the best cat back system to get at a decent price? Also, after that, what would be good headers to get?

 

So you're suggesting to wait until I can afford it all then just buy it all at once and then do it all in one weekend? How much would a decent setup cost?

 

Aren't Catco hi-flow cats rather expensive?

Also, how much would a stock cat obstruct the flow of a good cat back exhaust system?

So far from what people are suggesting, the best thing to do would be to get a Cat back exhaust first, then a hi flow cat, then headers, or wait and get it all at once.

Anybody have any ideas and prices they could throw out there?

 

If you don't need an exhaust right now save up and do it all at once. You will spend less money this way. You can then buy a cat-back and cat tailored for a TPI car. You wouldn't have to cut any reducers off and do unnecessary fab work. That will take time and could cost you a lot of extra money if you don't have it. There are other high flow cats out there but I think Catco and possibly Random technology sell a direct fit 3" TPI cat.

 

Well, thats one way to do it, but what I did is save up a little money and buy headers, save up again for the Y-pipe, save up again for the catback... etc etc... over the winter, and then installed the headers, Y-pipe, catback and tips all at once in a weekend.

The setup I have cost something like this:

Hedman shorties - $130
Hedman Y-pipe - $90 (?)
Hooker catback for '83-85 HO - $215
3"x16" exhaust tips - $15x2

I also had it to an exhaust shop later to have a peice made to fit where the cat was, and to weld the whole system together. That cost me about $100. Different shops will charge differently.

 

Does it matter that my car is TBI? Also, what would it cost right now if I got some headers, a hi flow cat, a cat back system, and everything needed to connect it all? Also, I would like a 3" system.

If somebody had a good setup in mind (cost effective, as well as high quality) that would be great.

It would be sweet if somebody could point me in the direction of something that might work well for me.

Overall I am looking for something that will obviously help on HP a bit, as well as make is sound deep and good.

Thanks guys,
Tony

 

By the way, I am looking for Dual 3" and it all has to pass emissions as well.

 

It doesn't matter that you have a TBI car.

The reason there are different headers/catbacks sold for TPI/HO and regular 305 and TBI engines, is that the TPI/HO stuff is all better (performance wise) than the reg 305/TBI stuff is.

A good example: A typical catback for a base 305/TBI Camaro or Firebird will be made up of 2.5" pipes all the way through.

Now... buy a catback for an HO/TPI car, even if its made by the same manufacturer, 99% chance its made up of 3" pipe and dual 2.5" outlets.

Basically, the HO/TPI exhaust system parts are MUCH more performance oriented than those made for the TBI/base 305 engines.

There are absolutely no fittment or installation differences between TBI and TPI exhaust parts, because both are still SBC engines. They all bolt on the same, they ae all routed (more or less) the same, and they will all fit your chassis, regardless of what engine is in there.

When you buy exhaust components for your car, even though you have a TBI motor, buy parts intended for a 5.7 TPI. Those are the best parts you can get for a 3rdgen.

 

TBI cat-backs are 3" as well. The TBI and TPI cat-backs are the exact same except for the reducer/mating flange at the end of the I-pipe that mates to the cat. I believe only one certain = flowmaster kit and the dynomax kit are 2.5" for both TBI and TPI. Everything else on the market is 3" with a 2.25" reducer for TBI applications and no reducer for TPI.

Without buying used you are looking at a solid $1000 to buy a complete quality exhaust system.

Air_Adam is right about fitment. The routing between the TBI and TPI set-ups are the same and the same hangers can be used. There were changes in the cat mating flanes over the years which warrents the need to offer mutiple kits. Since you want to replace the entire set-up right now you can bypass the reducer plagued TBI kits in favor of the TPI kits. If you just want to do one piece at a time than buy a TBI cat-back and it will hook right up to your stock cat. When you get a 3" cat later on you can cut the reducer off the cat-back and fab up the new cat.

 

I was thinking about getting this setup:

Hedman Headers: HED-68470 - $135.88
Hedman Y-pipe: HED-17470 - $98.88
Catco Direct replacement converter: CTO-9118 - $127.99
3" Flowmaster Force II Exhaust: FLO-17151 - $239.95

They are all out of the Summit Catalog. What does everybody think about this combination? Will the cat be a good selection for not restricting the flow for that price? Or would it be better for me to get a hi flow cat from elsewhere? Also, would it be best for me to go with this exhuast or something similar with dual outs instead. I think I want to have 3" for sure though.

And for the headers and y pipe, would you recommend me going with the ceramic coating or no?

Anybody have any ideas if this will all be emissions legal? I am in Milwaukee Wisconsin. I was told that these headers are not A.I.R. compatible, but as long as I am running an EGR and a cat I should be covered and I should pass. Is this true???? Also, what is EGR?

Thanks guys,
Tony

 

Your list seems fine. There are cheaper cats out there but they are often the universal type that will require more fab work on your behalf. If you do not have a means to accomplish that yourself it could cost you more in labor in the end.

Ceramic coating is very valuable. It extends the life of the header and keeps underhood temps down. Plus they look nice for a long time!

 

So the stock catbacks are 3"? Then why bother getting a catback?

 

Oh no.. just the aftermarket ones. The stock systems are a lame 2.25". I believe they were refering to TPI cat-backs being better than TBI cat-backs. Perhaps I missunderstood them

 

Doh, I read your post wrong. I see what you were saying. Sowwy

 

does your car have 3 inch pipe or a 3 inch cat?

if not, take it from me, DO NOT get a catback before you get headers. You will spend money getting a reducer put on there only to hack it off later when you want to get headers. Get headers with 3 inch y-pipe and buy the catback at the same time

 

I need this info in a hurry. I have the option toget a used 3" Flowmaster Force II Exhaust system for $125 shipped to my front door. It is FLO-17151 in the summit catalog.

My question is, would it work with my stock system if i dont get headers, y-pipe, or a new high flow cat yet?

Or would it just be wise for me to get this right away and then just get the headers and stuff as soon as possible.

 

no it will not fit unless you have a 3in cat. dont make the same mistake i did...get it all at once or get a reducer welded in and end up tearing it off when u want headers.

force II will be very quiet though, i would suggest getting the american thunder kit. How used is this kit?

 

You don't want that stock cat anyways. A nice high-flow will make your system sound better.

 

The exhaust has been used since March of this year.

So you say it will be much quieter, how about performance? I just dont know if I should get it or not. I mean if it is a good deal i'd take it, but if it isn't, obviously i dont want to take it.

What exhaust would you suggest then? And something reasonably priced as well.

Or should I just wait until I get the money and get a Borla?

But if I were to get it, would a new 3 in cat fit my stock exhaust? (will it basically replace my old cat?)

 

no it will not fit

i have the american thunder kit (flowmaster, 3 inch, mandrel bent, 80 series muffer) and its kind of quiet. Its loud enough to get your point across though. I havent ever heard the force II muffler. I would wait untill you have all the money to do it right. Or cut off your muffler after the axle if u want sound now...

 

so what did you end up doing?

 

I ended up not getting an exhaust yet, I am going to save up to get it all at once. But I am leaning towards an american thunder dual cat back when i do get one.

I think I am going to get a new posi rear end first with 3.23 gears.

I don't have posi now and I want it. I just dont know if i should go with 3.23 gears or higher.

Anybody know how bad it effect gas milage?

 

I'm running stock 3.23's with a new motor, 350ci/330hp, and I'm getting between 18 and 19 on the highway. I hope to do a bit better once everything is properly adjusted. At 70, I'm doing 22-2300 rpms. The cost of gas at three bucks + should perhaps be a consideration these days. As a consequence, your current highway gears and an exhaust mod would probably save you money. On the other hand, a hotrodder is a hotrodder is a hotrodder

JamesC

 

keep in mind your gonna need to recalibrate your speedo....



good decision about doing the exhaust all at once

 

I agree that you made a wise decision to do the exhaust all at once. Since you have a T5 you will need to buy the drive and riven speedometer gears to make it read correctly. I am not sure what DanTheMan posted but you do not need that for your T5 and a gear swap. Going from a 3.08 to a 3.73 in a TBI car could net you roughly a 5%+ loss in mileage. That is around 3mpg (give or take a few depending on a multitue of road conditions) at 65mph. There isn't much difference between the 3.08 and 3.23. I would go with the 3.73's or 3.42's. It is hard to beat a 3.42 gear for daily street use.

 

In order to show the correct speed, you'll need to swap out the drive/driven gears in the transmission if you have anything less than 3.08's--I believe that's correct. At any rate, check out jmd on this site for advice and proper gears.

JamesC

 

whoops, what i posted is a digital speedo calibrator. It was done by the previous owner i guess cause they didnt want to get speedo gears....

it comes with the most difficult to understand directions but it was done by a technician and the speedo is correct. The car had a posi and 2.73 stock....im not sure yet what the aftermarket gears are

 

So what you guys are saying is that if you get higher gears, you need to get a device to adjust your speedometer? How much does something like that cost? Is it easy to install?

Also, I think I am understanding to either go with 3.42's or 3.73's?

And how does that work, would I get a whole new rear axle, or would I get a kit that would turn it into a posi?

Also, I heard that it would be better to let a shop do it instead of me if it is a kit.

How much is a reasonable used rear axle? It would be nice if i could get a nice used axle with disc brakes and either a 3.42's or 3.73's.

Also, how much would a good kit cost with estimated shop labor as well?

And how much would 3.73's destroy my gas milage? I am just curious.

 

it will probably raise your rpms 500

disc brakes would require you to mess with the brake lines i think

jusding by your skill level you might want to leave it to a pro. If this isnt your daily driver, you can probably do it and we can help. Do you have tools?

 

I have some tools myself, but my cousin and buddy have a bunch of tools, as does my dad. I would also have at least one other person to helpe me with whatever I am doing.

Now I just need to find a decent priced rear axle, or go with a good kit.

 

First before I do any of that, I need to change my tranny mount. I haven't looked under the car yet to find out for sure, but I will tonight. My tranny bounces up when I give it a little gas. The harder I hit the pedal, the more it bounces. I am fairly certain it is a tranny mount.

I will be getting a new tranny mount, a polyurethane type, but not sure which one exactly.

Anybody have any suggestions on which tranny mount to get? I was thinking of getting one off summit for around 20.

 

Any poly one will suffice. I wouldn;t go with another GM rubber one.

You can do either. Some people find it easier and cheaper in the long run to replace the whole rear end if they get a good deal on one. The 4th gen rear is a poular swap because you could get a 3.23 posi or 3.42 posi and have disk brakes. The rear bolts right up except for the fact that you will have to do some work and buy/make some brackets to hook up the ebrake and your stock wheels will now stick out due to the 4" dimensional width between the 3rd gen rear and the 4th gen rear.

You can also just change the rear carrier and gears in the rear end you have now. This can be expensive ($500 at the minumum to have it installed with parts at a reputable shop). You can however, retain all your normal hookups this way. Check out Randy's ring and pinion for some of the cheapest and well put together differential kits on the web.

Since you have the T5 transmission you will need to replace the drive and driven speedometer gears. They are located inside the transmission and are accessable with the rear extension housing removed from the tranny. Check out this link to show you what is involved. I got my speedo gears from a GM dealer since I went with an LS1 rear with 3.42's. I just told them that I needed the gears for a '91/'92 TPI car with 3.42's and the T5. I think it cost me around $50 for both.

T5 speedo gear swap

Here are what speedo gears for the T5 look like. I would use the search function and read up on them more to have a better understanding of a rear gear swap.

 

How much wold a good 4th gen rear cost? It seems upgrading the gears may be a bit more pricey and possibly not as good as a rear from a 4th gen.

It almost seems that no matter what i do, either put a rear end in, or put a whole exhaust system, it will probably run me around at least 500 dollars if i want it done right. Exhaust would probably run me around 800, bc i want my headers ceramic coated and I want a 3 in y pipe and 3 in all the way back.

I don't know what I should do, this is getting depressing.

Previously I was under the impression that I could get a posi rear end installed for around 300 to 350, is that just not possible?

 

they dont make too many RWD passenger cars anymore for a reason..... i really love RWD and dont want to go back to a FWD car ever

whatever you do man, tell us how it works out

 

A good 4th gen rear will run you anywhere from $250 ro $300. I opted for the LS1 rear because the cheapest quote to have a ring and pinion set-up with all of the parts I had was $250. I had already spent over $300 for all the parts needed for the install. I also wanted to get rid of the crappy drum brakes in favor of the large LS1 rear disks. I still need to hook up the Ebrake cable but that isn't to hard and there are a few ways I could go about that. The increased width of the rear didn't both me either because I needed to replace two new rims due to an accident. I can now get two new rims with a 4th gen backspacing/offset and be on my way for $400. Some guys still run the stock wheels with a 4th gen rear end but they are awful close to the outside lip of the rear fender. If you are not planning on running different wheels I would just rebuild yours. You then know exactly what goes into it and you know eveything will hook back up when you are done. Some people choose to not get the speedo gears but they have to live with a speedometer that is inacurate from then on out. $300 for a rear install seems about right if you include the parts yourself. The only other option would be to find a used posi 3rd gen rear or do a lot of learning to attempt it yourself.

 

doesnt someone make aftermarket rear ends for 3rd gens?

 

Yes, but they are far from economical if you need them for a stock type application.

 

How much do you think it would cost if I got a kit to get posi and higher gears and had a mechanic or garage install it? And get the stuff for the speedo fix and have them install that too. Any ideas on what that would be?

 

You can get a 4th gen take out posi for $100 (you may still find some new for this price) and the ring and pinion intall kit will run you about another $100. I haven't priced new gears lately but I think they are just under $200 if not much less. You can go with a set of used gears but it isn't recomended. Too much risk. I would call around to your local transmissions and speed shops. Just ask for a quote telling them what you want to do. I have been quoted anywhere from $200 to $500 for labor and anywhere from $50 to $150 for the speedo gears. That was way back when when my wrenching experience was limited.

 

Ok, I think I am understanding a bit now. The 4th gen take out posi, is that just the casing with the gears in it that has posi? And is there a difference from the ring and pinion install kit and new gears? I thought they were the same thing.

And are you saying then, the speedo gears were 50 to 150, or that was the speedo gears and labor?

 

The take out posi is the carrier and a single part. It is called a take out posi because if you got an SS or firehawk (built by SLP) you could order an aftermarket differential as an option. They would then take out the stock posi and sell them for $99. They are considered used but only really have 2 or 3 miles on them if not less. You could also get a used one from any 4th gen if any of the take outs are not still available. The gears are the ring and pinion and nothing else. They are two hunks of steel with teeth in them. The install/rebuild kit has all the shims, bearings, seals, and marking compound that need to be replaced with a gear swap.


That 50 to 150 was for labor on the speedo gears. The gears were roughly $50 on top of that.

You can do a gear swap for much less if you use used parts and only buy a partial rebuild kit. Some people also have the know how to do it themselves and or know someone that will cut them a deal. For everyone else a rear end rebuild with new gears and speedo gears is pricey. The rewards are great but it comes at a cost. Doing somthing the right way isn't the cheapest thing. The best thing to do would be to shop wisely and call around to your local shops. You may even get lucky and find a good used 3rd gen rear. Check out the classifieds section as well as ebay. The only thing with that is you don't know if those rears need to be rebuilt. Sometimes it is more comforting in the end to know you bought new parts.