How much BHP will a downpipe add to GT4 Options

[alf15]

I'm thinking of getting a downpipe or de cat for my GT4, im just wondering how much extra HP will it add to my gt4.

I was looking on ebay and they have a good few, what are the downpipes for $60 like? Or what is safe price range for a good down pipe that wont crack etc

What do you think if these to downpipes.

Downpipe 1

Downpipe 2

Thanks

[lagos]

they will work fine as long as you use the support bracket on the bottom (1st link includes it, 2nd one doesn't). then you will probably need to grind down the flange to make sure it wont hit your actuator. other then that, it will work fine. it might crack or might not...it all depends. you might also run into a fair bit of boost creep depending on how free flowing your whole exhaust is.

as far as gains go.... i dont know any specific numbers, but it was a huge gain on my car. i would say that its a nice 20hp or so, just based on how it feels.

[alf15]

Thanks for the advise lagos! Whats boost creep, im just an beginer?

[eggman40]

Thanks for the advise lagos! Whats boost creep, im just an beginer?

its when your boost presssure rises higher than where you have it set. Basically if your car is set to boost at lets say 10psi. and then when your on the throttle, your car begins to boost higher than 10psi. you didnt intend for is to happen, thats why they call it creep. sometimes with a more freeflowing downpipe, the turbo will spool faster than the wastegate can discharge the excess exhaust pressure and keep it at the set psi.

hope this helps.

[presure2]

heres a dyno of a gen2 2.5" dp VS' stock:

i would bet the 3" will gain another 5+whp over that.

[Aus]

Not sure about exact gain, but you'll get much better throttle response (I found on mine that boost comes much quicker than with standard and on full boost much sooner. Saying that I fitted the dp when I did a load of other stuff on the car, so im not sure exactally what effect the dp had). You've got to keep an eye on the boost though, and get a boost controller if you aint got one.

I bought a cheapie one off ebay (XS power), some people say the have had problems with poor welds etc, but mine is fine...so far anyway.

This post has been edited by Aus: Dec 4, 2006 - 7:12 PM

[alf15]

Thanks for all the help lads, just got to send my car into the NCT (same as MOT) first then ill replace it.

Thanks

[Kadett]

On UK forum it is said you would gain 15 BHP and 15lb/ft torque. + you save about 10 kgs of weight. Stock DP is about 12-13kgs compared to 2-3 for a Aussie DP



That is a XS/SS downpipe, just so you know!!!! Did its job for about 3 months before it tore apart. With BPU 2nd gen engine.

This post has been edited by Kadett: Dec 5, 2006 - 8:40 AM

[Aus]

Thanks for all the help lads, just got to send my car into the NCT (same as MOT) first then ill replace it.

Thanks

Yeah thats a real pain in the ass! I found a 'friendly' MOT station

[Kadett]

That will be my problem too, to get thru the APK (Dutch word for MOT)
Dont want to spend 2-3 hours every year to replace a flens for a Cat section or put to stock cat in DP back :S

[lagos]

On UK forum it is said you would gain 15 BHP and 15lb/ft torque. + you save about 10 kgs of weight. Stock DP is about 12-13kgs compared to 2-3 for a Aussie DP



That is a XS/SS downpipe, just so you know!!!! Did its job for about 3 months before it tore apart. With BPU 2nd gen engine.

did you use the support bracket on the bottom?

[Kadett]

It wasn't me


Dont know if the owner did, found that photo on a dutch website of a guy who swapped the 2nd gen 3S-GTE into a Toyota Avensis (first model). So I guess he did not.

[jcbass7]

if you reinforce the welds and use the support bracket will the DP last a bit?

[raz128]

The main options from the GT4oc are either the XS Power ones or the Aussie ones. I'm running an Aussie dp and had no probs.

[lagos]

if you reinforce the welds and use the support bracket will the DP last a bit?

there is really nothing wrong with the way they weld them. the problem comes from the fact that the mid pipe puts too much stress on the downpipe when the motor torques inside the engine bay. having the support bracket in place helps reduce that stress. even the oem cast downpipe has 2 heavy duty support brackets on it.

if you search around, youll notice that almost all of the after market downpipes that are made, can crack at some point. ive had mine installed for about a year or so with the support bracket there from day one, and it has never cracked.

[x_itchy_b_x]

if you reinforce the welds and use the support bracket will the DP last a bit?

there is really nothing wrong with the way they weld them. the problem comes from the fact that the mid pipe puts too much stress on the downpipe when the motor torques inside the engine bay. having the support bracket in place helps reduce that stress. even the oem cast downpipe has 2 heavy duty support brackets on it.

if you search around, youll notice that almost all of the after market downpipes that are made, can crack at some point. ive had mine installed for about a year or so with the support bracket there from day one, and it has never cracked.

i have a ssac one. well had... ok well i had one. and it was fine. i used the bracket, but i think what makes alot more difference than the bracket is having sturdy motor mounts. if the motor doesnt flex then there isnt gunna be any stress on it. but if youve got, ill say a 91 mr2 then im sure by 2006 your motor mounts arent like they used to be. so then excessive flex breaks it. right? lol iunno. im just trying to figure out why the mr2 guys break them often. i remember seeing a couple threads with them broken.


ive broken two fully caged downpipes with the 5sfte. turns out on the dyno my 97's motor mounts where so bad my 5sfte was basically pushing the intake manifold flat against the firewall lol
after redoing my mounts with window sealant they dont move much and u can reallly feel the engine.

This post has been edited by x_itchy_b_x: Dec 6, 2006 - 10:32 PM

[jcbass7]

well here is what im planning on doing... let me know if it sounds decent.

I have the kirkasaraus poly mount inserts and im purchased the second DP that comes with the bracket. Its the SSAC downpipe. Are there any preventions i should take other than those to ensure a little bit of a longer life out of the dp?