Is a downpipe useless?

[TEAMONEINC]

Hey guys, i have a 97 4G63 on a stock 25, with an HKS intake, SSBoV, 3 inch cat back exhaust, running on stock boost. i am interested in upgrading my downpipe to three inches as well as upgrade my fuel pump, but have been told that this is pointless and will not feel any power gains until i upgrade my turbo. is this true?

 

[paranoidTSi]

Bull...the turbo spooled much faster and the RPMS moved quicker when I got a 3" DP on the stock T25. It'll be noticeable.

 

[leet]

Anytime you can free up exhaust flow on any turbocharged engine, you will see gains.

 

[oldman]

but have been told that this is pointless and will not feel any power gains until i upgrade my turbo. is this true?

No, and stop taking advise from this person.

 

[Meh987]

Bull...the turbo spooled much faster and the RPMS moved quicker when I got a 3" DP on the stock T25. It'll be noticeable.

Especially on the highway.

 

[Fahrenheit]

Bull...the turbo spooled much faster and the RPMS moved quicker when I got a 3" DP on the stock T25. It'll be noticeable.

agreed

 

[DSMTurboEclipse]

The downpipe will show improvement for sure, its a very important part of the exhaust system.

 

[Thomas91169]

upgrade to the 3" downpipe and get rid of the cat, either have someone make you a cat delete pipe(test pipe) or some downpipes come with the cat delete built in.

no sense in having a high flowing downpipe only to get backed up with a catalytic converter.

 

[dsmpride]

upgrade to the 3" downpipe and get rid of the cat, either have someone make you a cat delete pipe(test pipe) or some downpipes come with the cat delete built in.

no sense in having a high flowing downpipe only to get backed up with a catalytic converter.

Definately agreed. Although it isn't emissions legal, running a cat eliminating down pipe on my Talon is awsome.

Kent

 

[leet]

If you're going to run a test pipe on your vehicle, have someone tack weld a set of catalytic convertor heat shields around it. That way, it looks that much more like a cat to prying eyes.

I know it seems pointless, but someday it will come in handy.

 

[baldo]

just making sure i have this right...
the exhaust goes from the manifold to the

o2 sensor -> downpipe -> catalytic converter -> then whatever catback

correct?

 

[DSMunknown]

upgrade to the 3" downpipe and get rid of the cat, either have someone make you a cat delete pipe(test pipe) or some downpipes come with the cat delete built in.

no sense in having a high flowing downpipe only to get backed up with a catalytic converter.

Definately agreed. Although it isn't emissions legal, running a cat eliminating down pipe on my Talon is awsome.

Kent

yeah, but that means every time you go for your sticker, you gotta get under and bolt up a cat. so make sure you get your sticker in the summer (if you live in the normal-weather states), cuz in the winter you DEFINATELY dont wanna be out there

just making sure i have this right...
the exhaust goes from the manifold to the

o2 sensor -> downpipe -> catalytic converter -> then whatever catback

correct?

correct.

 

[tsi_daggie]

another alternative, rather than tack the heatshield on, is hollow out your stock cat, cut the ends off, and run a 3 inch pipe through it and weld flanges on each end. that way they have absolutley no clue it is a test pipe unless they take it out, plus it will be just a straight through design rather than haveing the exhaust bouncing around inside the cat.

this is just a watch your ass idea. cuz if a cop crawls under your car you can get a fine for not having a cat. that is a federal offense. not sure but i think around $2,000 fine.

 

[JessesTalon]

Yes get the downpipe... but watch out for boost creep... watch the boost very carefully on your first pull with it...

 

[TEAMONEINC]

Thanks for all the help fellas. i am thinking of gettin a high flow cat put on, because in cali, they are really strict on that sorta crap. if i a cop wants to ref my car, i'd be screwed. i'll be gettin this in a few days, so i'll let you know how it goes.

 

[punishercb]

Yes get the downpipe... but watch out for boost creep... watch the boost very carefully on your first pull with it...

Can it really screw up an engine on the first pull? What exactly does boost creep do? I mean, how does it physically work? Sorry about the odd question, but I like to know how things work.

 

[Talnz167]

Can it really screw up an engine on the first pull? What exactly does boost creep do? I mean, how does it physically work? Sorry about the odd question, but I like to know how things work.

I don't think the t25 can flow enough air to blow up an engine, but you could blow your turbo. Boost Creep is caused because there is too much exhaust gas leaving the engine and the small wastegate can't bypass enough to keep a consistant boost.

I didn't get a hf downpipe until after my 16g... and even before that it was creeping to 18 lbs before redline. Pretty much forced me to buy a SAFC with 550 fis to keep the EGTs below melting point

 

[Turbo Talon DL]

A downpipe will help out in any application over stock, but why is it that people want to run without a cat? They make racing, high flow pieces for $60 and dont hold back much, if any. If you're that concerned, just buy a $5 3" cut-out from summit and have it welded on between the DP and the CAT. Most muffler shops wont build an exhaust system without a CAT, its illegal man....

 

[TEAMONEINC]

well , i got my three inch piping along with a 3 inch high flow cat...it was a big ass difference in my high end power. i think the next thing i'm gonna do is buy a walbro fuel pump. money is very tight ya know.

 

[DSMunknown]

well , i got my three inch piping along with a 3 inch high flow cat...it was a big ass difference in my high end power. i think the next thing i'm gonna do is buy a walbro fuel pump. money is very tight ya know.

uuuhhhhh, hope u got a boost gauge on there, RIGHT? if not, that should be your very next mod. nothing else.

 

[SlowChild3]

WOW! I just install 3", I was nervous because all these people were telling me to port everything to stop creep. Well I have none. The only problem I had was failed to read it bolted to 2.5" pipe. Glad i'm a welder . RPM just race up pulling hard. And when I shift its like an auto, the boost is already there. Best mod so far!
My friend has 3k gt vr4, We put on dp cat eliminator, and his exhaust sounds mean! Mine sounds just like it was.

 

[thepoint4life23]

From what i know it will give you a littler more hp. If i had a turbo car i would run one.

 

[KUBAN]

I Got the Apexi N1 Dp with cat-eliminating, and thats it , Open DP, it made a wonderous difference.

 

[crazyman633]

Downpipes are glorious. You can gain over 20hp with adding one, and in 4 banger terms, thats huge. If you want my opinion, use the ATR Performance O2 housing eliminator downpipe with flex piece. It basically starts your exhaust system right off the turbo manifold, and it just goes into 3 inch pipe. It makes your car sound glorious too. I had an Apexi N1 on there when I bought my 98 GSX, I added this one and I could notice a difference still. It will turn your exhaust into a true turbo-back system. But FYI, you may have to get creative with the rest of your exhaust, its a huge piece of pipe.

 

[Booster-Shot]

Isnt the downpipe the most restrictive part of the stock exhaust? So yeah its going to help. I just bought my turboback from rnr, I cant wait.