kungfu

i put a 5" stainless Jasma system onto my type-r sti, sounds the bollocks.
down low it burbles to let you hear the engine note, and gets very loud outside when your going up throuh the gears....i've let my mate drive it while stood outside to hear it.
although it is loud outside it's spot on in the cabin, you can hear the folk in the back no-bother, slightly louder than standard but wot do you expect....

[Edited by kungfu - 6/3/2002 7:52:06 AM]

Bruiser.STi

Has anyone recently or ever swapped their 2.5" STi exhaust with a 3" HKS or similar system?? ANd if so, was there a notable performance increase and the main thing, was the exhaust note too droning on longer drives???
I don't wan't to have to shout to talk to passengers...

Is there any way of soundproofing the boot lining to prevent this excess noise???

Bruiser.STi

anyone???

mega_stream

I changed my Scoobysport mid and back box for a HKS Hiper last year. (Still got the Scoobysport Downpipe on)

The first thing I noticed was the exhaust note, very deep and burbly sound, you really can hear the boxer engine purring at tickover

Apply some gas and things get LOUD I'd say very loud on full chat infact. You can hear it with the windows up, its a different type of noise to the SS system I had b4, which was more kinda higher pitched and raspier. Not a system if you don't like to hear your exhaust when driving, best to try and go to a meet and have a listen to some systems before you decide if its for you.

Perfromance-wise I feel I did loose a bit of low down torque, but higher up the rev's its smoother and seems to rev-out much quicker through the gears, the gains higher up outweigh the losses lower down though

Seems the bigger bore, free flow systems are more commonly found on big BHP modified cars, so I guess that says something about them

Hope this helps..

Cheers
John

peccy

recently changed from standard to TSL 3" dp / BLITZ NurSpec R center and backbox.

i does get a bit droning on long drives, have to raise my voice to talk to someone in passenger seat, if someone is sat in back you do have to shout to be heard. not that it bothers me though

Bruiser.STi

Is the noise really that bad??? How bad was it with the original system????

Bruiser.STi

Is anyone else running a 3" HKS system.???

STi wanna Subaru

iTrader: (1)

I've got a scoobysport DP and HKS Super Dragger. The noise at tickover is wonderful. Open her up and it sounds great

Noise on motorways?? well it is slightly louder than standard but for me it's fine. when you're cruising it is only slightly louder than normal and certainly doesn't drown out passenger conversation (although on occasions I wish it would ). The only time the noise increases on the motorway is when you accelerate. The exhaust note deepens until you go back to light throttle.

I've put two layers of underlay in my boot so that will help with the noise.

Hope that helps

Guy

David_Wallis

Guy.. Any chance of having a ride in / listen to yours if you are ever around roundhay... as I wouldnt mind the scooby sport downpipe, but would like to know how loud it is first..

David

STi wanna Subaru

iTrader: (1)

No problem David, Next week sometime......when I've sobered up from this weekend

I'll drop you an e-mail

Cheers mate

Guy

BruceWarne

Am "downgrading" today - moving from 3 to 2.5".
Will tell difference on monday.
Oh, yes, turns out WRX exhaust doesn't fit perfectly on STi - different turbo angles or something like that. Is why I'm replacing it, exhaust was rubbing against steering link/joint(?)...

BruceWarne

Fitted the 2.5" one (twin dump, fully decatted etc).
Old system was 3", also twin dump.

Results?
Pretty much what I expected.
Quieter.
Much more driveable car (lots of low down torque).
The car feels/reacts faster over the entire rev range.
It might be slower from 7450 to 7500 rpm.

The 3" system introduced a lot of lag, and I'm glad I got rid of it.

Bruiser.STi

5" system???? holy ****e!!! must be loud!!!!

Tim W

iTrader: (1)

The difference between 2.5 and 3 inch systems rather depends on what else you have done to the car.

When I was running a standard TD04 turbo witha link ecu I needed more breathing so I replace my Scoobysport centre (2.5 straing through pipe) and Miltek back box with an HKS hyper retaining the Scoobysport down pipe...yes I still have a 2.5 inch restriction at the mounting flange beween the hiper's centre and the downpipe (perhaps that's where my 'rasp' comes from) but I did gain at the top end and loose a little low down, but with the way my car was mapped back then it wasn't really noticable...well appart from the noise level

Now I have a bigger hybrid VF22 turbo, the HKS exhaust manifold, custom up pipe and an HKS front mount I couldn't be without the 3" bore...although I could do with the car being a little quieter...so Plod tells me

I may replace the Scoobysport downpipe with a 3 inch BPM twin dump or similar in the not to distant future and see if there's much of a difference then in the way the car feels...

Anyway, yes there is a performance difference between a 2.5 and 3 inch system, if your running a small turbo IMHO it isn't worth changing from a 2.5 based system (assuming that it's already a free flowing system, not stock) but when you want big GG's with many mods then I think it's a vital mod.

So there

Bruiser.STi

Tim W- would you consider a VF24 running 18psi and pipercross induction worhty of a 3" system???

Razor2001

Is the JDM STi-7 turbo big enough to warrant a 3" or will the 2.5" pipe be better for torque ? I want more low down so the car is more driveable, I am sure I will be continue to be happy with how it pulls above 5,000 rpms, its the 3,000 - 5,000 rpm range that I want more response from.....so I guess 2.5 turbo back decat is the way to go ?

Cheers,
Ray

Katana

Don't know what mine is. But you can fit 2 fists in it.

ZAZ

I was running a 3" HKS downpipe with 2.5" Magnex centre and Scoobysport BB which was Ok but now I have had a 3" HKS Hyper centre and back fitted the low down torque has gone a bit but it does sound awesome.
Will run it like that for a couple of months and then think about changing the downpipe for something a little smaller (2.5") to try and get the torque back and make it more driveable.

Razor2001

nice thread

bottom line 2.5" better low down pull and torque......3" more pull up top and overall faster straight line but more lag ?

cheers,
Ray

Mr Footlong

iTrader: (7)

I have a full 3" system from the turbo to the backbox and I have a lot of lag and no real power until at least 4000-odd.
STI2 with Scoobysport full 3" downpipe and a Nur Spec R' system.
On the first scoob, I had a normal Scoobysport DP and the blitz and that was a little better lower down the range.

Cheers,

Nick

WREXY

Why not compromise and go for a 2 3/4 inch?

Tim W

iTrader: (1)

Brusier, can't remember if a VF24 is a large turbo or not, doh, but assuming it is fairly big then a 3" system will help, but as Ray has sumised you will probably loose a little low down grunt.

On my car (a lightly modded MY98 UK) my set up is a bit track biased, so I've ended up with a power band from about 4000 rpm to the 7000 rpm limiter, with peak torque at about 4500rpm. On a charge I rarely drop below 4500 on gear changes, so I'm well in the power band, so I don't notice the relative lack of low down grunt on the road and especially on the track. Torque and Power wise I'm down on the old dinky little TD04 turbo set up until 3500 then it just screams away

I really ought to put my car on the rollers and see what happens with a 3" and a 2.5" system one day

Ray, re the Sti VII I really know nothing about them I'm affraid, and before a smart alec comes in yeas I know I'm not up on the others that much too From what I've heard the VF30 turbo on the VII is quite large, and maybe it would respond well to a 3" based system, but I also understand that the VII suffers from boost spiking when decatted...worth seaking out the threads about that that are in Drivetrain I think!