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Discussion Starter · #1 ·
Yes, I searched already. It makes it hard to search things with less than 4 letters with this engine. So I think I want to finally buy a 3" dp. What are most people buying, the one w/ the highflow cat or the one w/out? If I buy it w/out the 3" cat, can i run my old cat, or will it perform poorly? Or could I just buy a 3" w/out the cat and buy a 3" cheap cat off of ebay? Must a hi-flow cat be welded on or do they bolt up? Just looking for the most cost effective route to do this. I like being able to avoid bringing my car into the shop, but if i must i will. Sorry if this topic has been beaten to death, but my search didn't yield the results im looking for. ;oops:
 

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Get one with cat, or get one without and have it welded into your pipe....

Don;t use your old one, which is probably very restrictive...
 

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i just purchased a 3 inch DP with a high flow cat. it would be numb to keep the old cat, cause its 2.5 inches, its restrictive, and it defeats the purpose of a 3 inch DP. the power increase with mine was huge, and MP logged greater power gains on their DP WITH a cat.
 

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If your looking to be cost effective, then get one without a cat and do the o2 extension mod, or hookup an o2 simulator...and if you want to be envorimentally freindly(which I'm not a tree hugger, but i would suggest it) buy a cat and get it welded into the DP, but you may have to move the o2 sensor around.
 

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Yeah it would be most cost effective to buy a DP without a cat and then get a cheap 3" high flow one and put it in. It is a tight fit getting a cat to fit in the stock location with a 3" DP and will require welding or some good exhuast clamps which i dont recommend because they arent the best at sealing and can allow the pipes to come apart. If you have access to a welder or some one to weld or a cheap place to do it the go that route, but if you dont then just buy the DP with a cat already installed and just bolt it on yourself.
 

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btw, i just wanted to add something to this, a 3inch downpipe is good, especially on top end, but take into account a few things like, whats the exhaust side outlet on your turbo? I can bet its no where near 3inches, i had a T3/4 57trim turbonetics with a .63 ar on my last car and i used a 3inch Dp, and the exhaust side on the turbo still didnt have an outlet that was thatbig, and i had the big exhaust side option on that turbo so it was 2.75inches.

Im not saying that there is no point in a 3inch Dp, for top end it will be good, but a 2.5 inch cat later on isnt going to do much. For the simple reason that as exhaust gas flows down the Dp, it gets colder, the first 18-24inches of an exhaust are most crucial, after that you can go smaller since if you do, you`ll be compressing the gas, thus making it hot again and helping velocity out of your tailpipe assuming its a fairly free flowing exhaust. And of course the less bends the better.

So getting a cat based on size alone isnt really going to yield much difference, but if its a cat thats extremely dense compared to a high free flowing one.. then maybe... its up to you 400bucks seems a little steep bang for buck
 

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I did The JT 3" w/out Cat.

I love it.
I just have clear the CE light every few hundred miles.

I haven't Gotten my logger yet, so I'm not Sure if it's front or rear throwing the code, but when it goes, the Car runs like a turd =0/

PS, there is *just* enough room for a cat in the JT exhaust.
make sure you get a small catcon, or it will be tough to make work.
 

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On my DP at least, the cat is very soon after the turbo, mine reduces to 2.5 after the cat, allowing a full 3 inch flow through the cat, this seems ideal to me because the cat causes restriction anyway, may as well make it as little restriction as possible.
 

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Discussion Starter · #10 ·
G96nt said:
I did The JT 3" w/out Cat.

I love it.
I just have clear the CE light every few hundred miles.

I haven't Gotten my logger yet, so I'm not Sure if it's front or rear throwing the code, but when it goes, the Car runs like a turd =0/

PS, there is *just* enough room for a cat in the JT exhaust.
make sure you get a small catcon, or it will be tough to make work.
Is it too loud w/out the cat? Also, I have saabsport. Are the JT's superior performance wise (noticeably) or is it just perference?
 

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Fit and finish, I'd take a JT anyday over the budget ones Offered here.
the only issue the JT poses is that The 02 sensor is AFTER the big bend so the Sensor reads funky. 10 minutes with a welder will fix it.

the only thing with the JT is that it's Slip-fit, which means your Exhaust guy will have to modify either your d/p or saabsport a little if you're not using a JT cat-back, but it's an Easy fit.
 

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biggy said:
btw, i just wanted to add something to this, a 3inch downpipe is good, especially on top end, but take into account a few things like, whats the exhaust side outlet on your turbo? I can bet its no where near 3inches, i had a T3/4 57trim turbonetics with a .63 ar on my last car and i used a 3inch Dp, and the exhaust side on the turbo still didnt have an outlet that was thatbig, and i had the big exhaust side option on that turbo so it was 2.75inches.

Im not saying that there is no point in a 3inch Dp, for top end it will be good, but a 2.5 inch cat later on isnt going to do much. For the simple reason that as exhaust gas flows down the Dp, it gets colder, the first 18-24inches of an exhaust are most crucial, after that you can go smaller since if you do, you`ll be compressing the gas, thus making it hot again and helping velocity out of your tailpipe assuming its a fairly free flowing exhaust. And of course the less bends the better.

So getting a cat based on size alone isnt really going to yield much difference, but if its a cat thats extremely dense compared to a high free flowing one.. then maybe... its up to you 400bucks seems a little steep bang for buck
Have you proved all of this on a dyno? If not, I'll stick to my 3" dp with the 3" cat.
 

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I dont' know if they're the BEST downpie/exhaust, but I can't imagine another making *much* more power... if any.

you have to figure, I went from trapping @ 96MPH to 100.5 with slipping clutch and hittng fuel-cut. the frikken thing almost makes TOO much power.

I bet with a REAL clean run, it's going to trap at about 102MPH.
maybe, if I get a chance I'll take it back up to F1 soon.

I would reccomend a full JT system for anyone that's looking for max perfomance and best fit/finish. just make sure you're not in a rush when you order it.

Also: I ordered the no cat, Single muffler system and was sent the no cat, 2 muffler. ( I think Nick felt bad about the wait time)

I think it was $560 to my door, and took all of an hour to un-install theold stocker and re-install the new one
 

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That price point of $560 is very interesting. Now for comparison, the MP dp without cat was $250 I beleive. Its not listed on the site anymore, so this is from memory. And assuming you can even get the thing anymore. Then its $335 for the 2.5" Saabsport exhaust. So here you're paying $585 for a 3 to 2.5" full exhaust. And you still have to pay the shipping. Looks like the JT is a good deal.

I have to say though, g96, when I saw your car, it looked kind of nasty the way the very end of the exhaust was set-up. I seem to remember some clamps being very visible from the back of the car. Was this temporary? Or am I just going crazy?
 

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nope, it's how it is.
it's a slip-fit exhaust and uses u-bolts to hold it together.

I suppose if I cared enough, I could pull it closer to the chassis and flip the u-bolt over.

also, judging from some of the JT pictures, I have the tip on sideways. it's got a bend in it whch I just kinda pointed up.. I think it's Supposed to go to the Side.


To be honest, it could be purple and sound like a moose as long as it performed well.
it's not like the thing's a show-stopper.
it's got 160k miles and looks it.
 

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I hear ya about the function over form. As my car gets higher mileage, things tilt more towards function for me too.
 

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Discussion Starter · #17 ·
Wow, the JT is $560 WITH the 3" dp? That is pretty damn good. Anyone want a saabsport exhaust? ;) I like hearing another person mod their car w/ high miles. I have 110k on mine. I guess its also good the clutch hasnt gone yet, it will give me the opp to put in a heavier duty clutch.
 

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yeah.. mine started slipping the other day... even WITH the spec stage2 and sachs "R" pressure plate =0/ and nick isn't returning my e-mail...


I'm assuming he's on vacation... I'll give him a few days.
 

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Discussion Starter · #19 ·
G96nt said:
yeah.. mine started slipping the other day... even WITH the spec stage2 and sachs "R" pressure plate =0/ and nick isn't returning my e-mail...


I'm assuming he's on vacation... I'll give him a few days.
What type of bill should I expect if I buy the clutch online and bring it to ta shop
 

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I don't want to pull this too-far off topic, but the clutch + $500 labor..tops
I'd also search to find a stronger pressure-plate, too... maybe go to ACT/centerforce/exedy and find a euro car with the same trans/housing

FWD transmissions Are relatively easy to replace. it's the extra stuff, like having them replace/re-pack axles that costs the $$
 
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