I need to get/make/buy a new exhaust system for my TGP. The old system isn't so hot anymore. I need some facts and opinions here. What are some good setups? I know some people are running with no cats, some with no mufflers, some with both and/or a combination of those. What size piping should I run? Good materials to use? Mufflers: yes or no? If yes, what are some good brands and models of mufflers that you guys have tried and liked? Any other general information, facts, and opinions are greatly appreciated.
Now, some info about what I would like: I will be getting new exhaust from the downpipe to the exhaust tips. I would like to keep the stock exhaust tips. I don't NEED to run a cat. The two states it will be run in is Minnesota in the summer and Florida during all other seasons, and neither state has safety checks, so I don't NEED a cat, unless there are any benefits to running one (doubt it). I'm looking for above all something that sounds good and performs well. As long as it isn't rattling windows loud, I'm okay with dealing with a little noise. And finally, durability: I want the exhaust to be durable and not rust out. It would be nice if it looked decent and didn't rust up and look nasty. Should I go with stainless steel or.... recommendations??
Everyone feel free to post your thoughts and opinions here; I want to have an AWESOME exhaust!!! :icon_twisted: :icon_cool:
As of right now, I'm looking at a stainless steel, mandrel bent exhaust. I still need some input. :icon_neutral:
Why not aluminumized 2.5 mandrel bent with high flow cat and some magna flows?
What will hold up better: stainless steel, or aluminized? Any benefits to running one or the other? What would pricing be between the two? One more expensive than the other? Thanks for the reply BTW.
Nick, in Minnesota, all motor vehicles after a certain year, and I think it's like 84ish, need to be equipped with a catalytic convertor. That being said, I tore that bastard out lol. Like you said, we don't have checks. My setup is real simple and cheap: Deleted Cat, new pipe to the mufflers (which play a vital role in the cops NOT pulling you over for a loud exhuast and writing you a ticket for not having a cat), the mufflers I use are two Raptors...Raptor is a cheaper brand...like $26 a muffler, and you can get them at NAPA and Advance Auto...Probably more places. They are cheap and they give me that beautiful low rumble, like a muscle car, I have desired for my car...no cat and $52 worth of mufflers...only thing is, you need to know someone who will remove the cat; even my best buddies at Tires Plus wouldn't because they know it means BIG consequences for them.
just gut the cat converter. In NY you are required to have one in place, but it does not have to be functioning, unless it is a 1995 or newer.
Previous owner already gutted my cat and did a horribly shitty job on it. Also I NEED a whole new exhaust system from the downpipe back. The only things I will keep are the headers, downpipe(maybe), and exhaust tips, otherwise, EVERYTHING has to go for a new system. In the 2 states I will be running it in, I don't need a cat.
cats FTL. i hacked that off mine and put a cutout in its place. soon to change to 3" piping all the way though
2.5 inch mandrel bent from the stock DP all the way to the tips
Magnaflow SS Mufflers
NO CAT
SLP Tips
thats how i roll dawg......
hahahaha
yeah, 2.5" mandrel bent all the way back, no cat, no resonator, and either Magnaflows or Dynomax Ultraflo mufflers (i think they are really the same thing). if you had an upgraded turbo with a larger turbine i'd say 3" but what's the point with that T25 bottleneck (i'd also recommend a custom mandrel bent 3" V-band downpipe starting at the turbine going all the way back). as far as stainless steel versus aluminized steel...they have thier pros and cons. stainless is alot heavier but it will last forever. if you live in an area that uses salt i would go stainless. if not i would just go with aluminized steel.
a highflow CarSound cat isn't that much, and i doubt it hurts flow. i'd at least consider one. i'm defintely going to use a cat in my GS since i don't want it to sound raspy. if only it was turbo'd instead. LG5 with no cat or resonator = no raspy exhaust. L67 with no cat or resonator = sounds like total ASS.
Right now, it has all stock exhaust with NO resonator and a gutted cat. I think I will go with a 2.5" mandrel bent exhaust from the DP back to the Y split. At the Y, I'm thinkin of going 2.25" to each Magnaflow muffler. I would LOVE to use stock tips, but I've been told that they're only 1 and 5/8 inch diameter :icon_eek: Are there any tips out there that look the same, but have bigger diameter? I want to use stock or stock looking tips if at all possible.
What do you guys think so far?
Thanks
Nick
Stock, TGP's don't have resonators. Ractive makes some nice oval tips that fit nicely in the bumper cutouts. Jeff (kuntzie) has them on his car.
Quote from: TGP Nick on February 21, 2007, 11:27:26 AM
Right now, it has all stock exhaust with NO resonator and a gutted cat. I think I will go with a 2.5" mandrel bent exhaust from the DP back to the Y split. At the Y, I'm thinkin of going 2.25" to each Magnaflow muffler. I would LOVE to use stock tips, but I've been told that they're only 1 and 5/8 inch diameter :icon_eek: Are there any tips out there that look the same, but have bigger diameter? I want to use stock or stock looking tips if at all possible.
What do you guys think so far?
Thanks
Nick
oh that's right, i think the resonator thing started with the 3100s in '94.
the diameter that far back doesn't really matter as much, ecspecially when you consider there are two of them. and for that matter, going with 2.25" pipe after the Y would probaby be fine as well as the mufflers. i think some '04+ GTP tips would look pretty good on a TGP.
Quote from: TurboSedan on February 21, 2007, 01:24:49 PM
the diameter that far back doesn't really matter as much, ecspecially when you consider there are two of them. and for that matter, going with 2.25" pipe after the Y would probaby be fine as well as the mufflers.
I guess I didn't consider that there are two tips.... then I WILL run the stock tips. Okay then 2.5 inches DP back, do you guys think I should run 2.5" piping from the Y to the mufflers, or step down to 2.25" for the Y?
Thanks
Step down to the 2.25. I'd see how much the "Y" cost comparing the 2.5 "Y" vs the 2.5 to 2.25 "Y".
Post pics when you do the system.
lets do some basic high school math. 2.5 inch piping has an area of 4.90625 square inches. dropping to 2.25 piping at the Y is 3.9740625 square inches for each pipe or a total of 7.948125 square inches for both tail pipes. The stock tips at 1 5/8 inches equals 2.072890625 square inches each or 4.14578125 square inches total for the 2 tips. So your flowing just under 5 square inches back to the Y where it gets bigger at a total of just under 8 square inches then come the OEM tips at just over 4 square inches total. The bottle neck would be the tips. Dropping to the 2.25 at the Y flows just fine even dropping to 2 inch at the Y would still give a total of 6.28 square inches for the Y section of the system. I would get bigger tips of at least 2 inch to stop the bottle neck at the tips.
Tim
I will DEFINITELY post pics when I get this done. Sounds like running a 2.25" Y will work the best. Undecided on the tips... I am considering cutting the tips and welding a larger piece of pipe onto where they attatch to the mufflers. What would be the best size to run for the tips? You said I should run AT LEAST 2" on the tips, but ideally, what would be the best size? You seem to know what you are talking about with exhaust.
i left my stock exhaust size on from the subframe back, which is 2". its WAAAAY too small and it restricts the hell out of the engine. can't boost past 9psi without the whole car sputtering and puffng out black smoke
On the W-body forum, someone is suggesting that I run a 3" exhaust.... should I?? Why or why not??
http://www.w-body.com/forum/index.php/topic,54852.0.html
This is what is going on over there... I have suggestions from running 3" exhaust to all kinds of crazy sh**. Any suggestions for exhaust size?
As I posted on the other board, 2.5'' is adequate. 3'' would not hurt anything though, I'm not sure how much(if at all) it would help with a relatively stock engine & the T-25 still in place though. As far as I know, only one person has done a 3'' exhaust, and that was Jason(eclipse5302). He had a LG5/getrag 282 swapped Cutlass with custom tuning, alcohol injection(not sure if he used it though?) etc. so there's no good comparison of his car vs. a similarly modded one to compare it to(his car dyno'd 202hp and 275 ft lbs) as we don't know what tuning he had done, what type of dynomometer that was on, etc.
Again, look at what Josh's Cutlass made on the dyno with a stock TSTE exhaust(minus the cat I believe, he can answer that for us). The stock exhaust piping is what, like 2.25'' and then necks down near 2'' at rear from what I remember(I never measured it, but it seemed smaller than the other piping by a bit, it's been 3yrs+ since I've seen the stock TGP piping though...)
Quote from: mfewtrail on February 22, 2007, 06:59:47 AM
Again, look at what Josh's Cutlass made on the dyno with a stock TSTE exhaust (minus the cat I believe, he can answer that for us). The stock exhaust piping is what, like 2.25'' and then necks down near 2'' at rear from what I remember(I never measured it, but it seemed smaller than the other piping by a bit, it's been 3yrs+ since I've seen the stock TGP piping though...)
yeah, stock '91 Cutlass exhaust with the exception of the obvious TGP downpipe and a test pipe in place of the cat all the way back to below the rear seats. that's where i welded on the exhaust from my old Turbo STE (which is the same size pipe). not only that, but this was all going into two VERY rusty stock 160,000 mile mufflers that i'm sure flow like dogshit and i really think i lost out on a few whp there.
while i do think larger exhaust would help (sounds like you're on the right track), the bottleneck is really the turbine. like Matt said, 3" won't hurt anything and might be a good idea if you plan on upgrading the turbo later on, but for a stock TGP i think 2.5" mandrel bent exhaust going into 2.25" mandrel bent pipe at the Y would be great. just make sure you use straight through mufflers and mandrel bent pipe not crush bent.
Okay yeah I'm still undecided on the exhaust size... I know with our turbos, the less backpressure the better, but would 3" have TOO LITTLE backpressure? Possibility? Also, do you guys think I could/should make a bigger downpipe as well? At this point, I'm leaning toward having 2.5" exhaust from the DP to the Y, with a 2.25" Y.
I know TGPvsTIII, you were comparing the 2.25" Y versus the 2.5" Y... I'm a little confused with what you wrote.... would the 2.5" Y flow much better than a 2.25" Y?
Thanks for all your help guys!
Nick
Quote from: TGPvsTIII on February 21, 2007, 07:35:43 PM
lets do some basic high school math. 2.5 inch piping has an area of 4.90625 square inches. dropping to 2.25 piping at the Y is 3.9740625 square inches for each pipe or a total of 7.948125 square inches for both tail pipes. The stock tips at 1 5/8 inches equals 2.072890625 square inches each or 4.14578125 square inches total for the 2 tips. So your flowing just under 5 square inches back to the Y where it gets bigger at a total of just under 8 square inches then come the OEM tips at just over 4 square inches total. The bottle neck would be the tips. Dropping to the 2.25 at the Y flows just fine even dropping to 2 inch at the Y would still give a total of 6.28 square inches for the Y section of the system. I would get bigger tips of at least 2 inch to stop the bottle neck at the tips.
Tim
Just doing the math and making the numbers easier to read the 2.5 pipe is about 5 square inches to flow. The Y section with 2.25 pipes is a total of about 8 square inches. So as the exhaust hits the Y the Y is actually bigger and should have no issues flowing. I also said if you did the Y in 2 inch pipe the 2 would flow a little more then 6 square inches 1 whole inch more then the pipe feeding it. The restriction would be using the factory tips. With them at 1 5/8 inch the 2 only flow a little over 4 square inches thats less then any other part of the system.
Personally I don't think a 3 inch system would be a bad idea if you can get it done. A 3 inch pipe is 7 square inches. My only thoughts would be is if the turbo is to small for 3 inch. I don't think the engine is too small. I would have to go look and see what the dodge guys issue was with too big of a pipe on the cars running the small mitsu turbos. Turbosedan might know. I run a 3 inch mandrel bent system with 3 inch cat and no muffler on my T3 turboed TIII 2.2.
Tim
Ok thanks for clearing that up.
How big is the stock downpipe?
Well I found a thread: http://www.tgpforums.com/index.php?topic=852.0 That told me that the stock DP is only 2.25"! :icon_eek: That NEEDS to be made bigger... does anyone with experience here know if I can cut the stock DP, use teh stock flange/mounts/coupler, and as you go further down the DP, I was thinking of cutting it there, and welding a 3" pipe onto there. Could I do this?
Also, in that thread, they talk about certain resonators giving too much backpressure, due to their design. Does anyone know of a resonator they recommend running that doesn't have the backpressure problem?
Thanks
:laugh: Beat ya' to that post by a minute. ;)
As for a resonator, check with your local exhaust shops...several of them in my area carry straight through resonators(not shitty glasspacks!, they do look similar though).
Ah sweet! Thats awesome! :laugh:
Yeah I'll check the local shops for a good resonator then. I was hoping that someone here has replaced their resonator with something they liked?
Quote from: TGP Nick on February 23, 2007, 11:33:44 PM
Well I found a thread: http://www.tgpforums.com/index.php?topic=852.0 That told me that the stock DP is only 2.25"! :icon_eek: That NEEDS to be made bigger... does anyone with experience here know if I can cut the stock DP, use teh stock flange/mounts/coupler, and as you go further down the DP, I was thinking of cutting it there and welding a 3" pipe onto there. Could I do this?
The largest down pipe with a auto tranny will be 2.5 inch.Been there done that! :icon_mrgreen: I THINK the flange on the down pipe is cast iron,so you wont be welding exhaust pipe to it either. :icon_sad:
Quote from: flybynite on February 24, 2007, 02:22:58 PM
The largest down pipe with a auto tranny will be 2.5 inch.Been there done that! :icon_mrgreen: I THINK the flange on the down pipe is cast iron,so you wont be welding exhaust pipe to it either. :icon_sad:
Ok thanks- good to know. Looks like I will be sticking with the stock downpipe. :icon_frown: Hopefully that isn't TOO much of a restriction...
Still lookin at a 3" exhaust from there back, though.
This is a about the best I can give ya Nick. Maybe if it was light out, it be better. I believe your money shot is picture 282 ;)
http://s138.photobucket.com/albums/q276/JimmyTGP/
[quote from Jimmy] I had to use the DP, but I had a guy weld a 3" on to that, and all the way to the back, including the Y with 3" tips[/quote]
Jimmy had a 3" pipe welded onto his downpipe coupler... so it CAN be done. He has a 5 speed though, not sure if that makes a difference...
Jimmy's system was done with the auto still in the car and the pipe was welded on after the downpipe joint. The entire downpipe is still stock on his. This picture was taken from the passenger side of the car so the engine is to the right and the tail lights are left. You can see the pipe bow upwards to the downpipe joint on the right side of the picture. http://s138.photobucket.com/albums/q276/JimmyTGP/?action=view¤t=100_0282.jpg
Tim
So if I'm understanding this correctly; Jimmy's downpipe is the stock 2.25" cast iron pipe? And then from the DP to teh mufflers, he is running 3" exhaust?
Correct Nick. The guy told me that he would try to do something to the DP but as we all can see, apparently he just couldn't :icon_rolleyes:
The main issue I see with the down pipe is the top end where it bolts to the turbo. If the turbo used a V band clamp making a new pipe would be easy. At the bottom end it needs to flex some so a flex joint similar to what is on the crossover can be used and a bracket used to secure it to the back of the engine similar to what is there with the factory downpipe.
Tim
Okay I see. I guess I'm stuck with the factory DP. :icon_frown:
Unless you're planning on some serious mods, the factory downpipe will be just fine.
I'm lookin at POSSIBLE FUTURE mods, so I guess I'll just do 3" from the DP to the mufflers.(with a resonator and mandrels in there, too.)
If/when I'm ready to do more, I'll work on the DP, but for now it will suffice.
Here is my old down pipe.It's attached to a tdo4 that held a steady 18lbs.It starts out as 3 inch at the turbo then is reduced to 2.5 inch all the way till it splits at the rear of the car. :icon_cool: later..Adam
Why is there another O2 sensor coming off the downpipe??
Quote from: grinders_18 on February 27, 2007, 06:17:44 PM
Why is there another O2 sensor coming off the downpipe??
Thats the only one i have.I moved it down stream a little to keep from hurting my wideband o2 sensor.
Ok, I'm lost. You're running one or two O2 sensors?
He's running ONE O2 sensor.
Ok lol...thanks for clearing that up.
I've been doing some digging for exhaust parts- I have a new question.
For the Y junction, I found this: http://www.magnaflow.com/02product/shopexd.asp?zone=main&id=861
Seems a little spendy though- what do you guys think: should I buy a complete Y like the above, try to make one, or... any recommendations?
Thanks
I'll say :thinking: make one
Nick, shop around at some local exhaust shops. Most carry y pipes or will make you one. Are you welding up your own exhaust or having a shop do it?
EDIT: http://www.sfxperformance.com/parts/MAG10768.htm <---that place lists the magnaflow y pipes much cheaper. ;)
I will be having a shop ASSEMBLE and WELD the exhaust together, but I'm looking to see if I can get all the bits and pieces of exhaust together a little cheaper.
Matt- on that site, I don't see any Y's that are 3" inlet and 3" outlets as well, :icon_confused: like the one on the link I posted.
I thought you were going with the 2.5'' size. Here's the 3'' to 3''...
http://www.sfxperformance.com/parts/MAG10798.htm
Quote from: mfewtrail on March 02, 2007, 02:21:49 PM
I thought you were going with the 2.5'' size. Here's the 3'' to 3''...
http://www.sfxperformance.com/parts/MAG10798.htm
Yup- that's the one. Perfect. Half price too! :thumb: Thanks!
Ok that is the Y pipe I'm going with (link above).
Now, I am looking at mufflers. What are the dimensions of the stock mufflers? (length, width, height)?
Here is the link where I'm looking at mufflers: http://www.magnaflow.com/02product/02muffler.asp
Can't help you there since my car is mufflerless. :laugh: If nobody answers by next week though, I'll measure a stock muffler for you at the junkyard.
Thats ok :laugh: I was hoping someone will reply- I don't wanna walk through waist deep snow to get to the garage (where the TGP is stored). :icon_eek: :laugh:
BUMP... anyone know what the dimensions of the stock mufflers are? (length, width, height)?
Thanks
I would tell ya but i don't have stock ones ether
http://www.zzperformance.com/grand_prix/products1.php?id=537&catid=110
HTH
Quote from: GPChief on March 04, 2007, 07:59:26 PM
http://www.zzperformance.com/grand_prix/products1.php?id=537&catid=110
HTH
Thanx for the tip, but I'm going with a Magnaflow Y- it is cheaper, and the perfect size I need. Thanks anyway :thumb:
Does anyone know/have the dimensions of the stock mufflers? (length, width, height)?
Thanks everyone
3" y-pipe outlets are completely pointless, you realize this yes? Going that big is going to hurt velocity. Two 2.5" pipes already way outflow a single 3" pipe. I thought you were keeping the stock 2.5" downpipe anyway?
Quote from: GutlessSupreme on March 05, 2007, 12:04:10 PM
3" y-pipe outlets are completely pointless, you realize this yes? Going that big is going to hurt velocity. Two 2.5" pipes already way outflow a single 3" pipe. I thought you were keeping the stock 2.5" downpipe anyway?
Hold on- YES I am keeping the stock downpipe. From there, I was going to run 3" exhaust back to the Y. I am unsure of what to run for the Y. From what you said, I should be running 2.5" pipes from the Y to the mufflers, correct? I need your input on this...
Well I'm just saying.. 3" back to the Y would be ok if you DO plan on upgrading the downpipe to 3" in the future (and getting a turbo that could actually take advantage of such diameter).
If you're always going to have a 2.5" downpipe, having a 3" exhaust is going to do nothing but hurt your wallet and possibly performance. It sure as hell won't increase flow if it's bottlenecked at the 2.5" downpipe.
And if you were to get 3" back to the Y, take this into consideration:
3" pipe flow area: 7.07 sq-in
2.5" pipe flow area: 4.91 sq-in (x2 pipes = 9.82 sq-in
So even going from a 3" pipe to two 2.5" pipes is a big increase in overall area, there's no reason to go any bigger after the Y.
Maybe I'm missing some hidden mystical logic in this.. I don't understand how having a pipe split into the same size would ever help anything, as the flow would just be split and velocity would go down.
Stock 2.5 DP to 2.5 mandrel bent piping all the way to the mufflers
and be done with it....anything more is overkill unless your Kuntzie :laugh:
Ok thanks for the info guys. I'll do 2.5" from the dp to the mufflers then (including 2.5" Y)
Thanks. ;)
you won't be disapointed thats a good setup
Dave, is that the setup you have?
Sure is
Ok thanks ;)