i would like to know whats the best uppipe for a 2002 WRX? (NOT THE CHEAPEST!)

 

THE ONE THAT GIVES THE MOST H/P.

 

Probably the MRT one, but I can't find the pic. It's got a flexi joint in it which people currently think is important. If you ask Dave T-S nicely, I think he has a pic......

Matt

 

Ive got a pic if you are interested?

Jamie

www.j-w-racing.com

 

 

The standard one has a flex joint because it is made of mild steel and cast iron, both very brittle materials.

Fully anealed stainless steel is quite flexible, so we have not included a flex joint. Flex joints will evetually fail, a well made, solid, stainless pipe will not.

I doubt there is much performance difference between most up-pipes, so ensure the one you buy is fully stainless and has threaded holes on the top flange, to take studs. Its difficult to tighten nuts, when you can't get a spanner on the bolt head

 

Pete,

Any comments on a non-flexi-jointed one eating gaskets?

Thanks
Richard

 

Richard

We found that some of our first batch didn't have the flange machined flat, after welding. Hence the problem

Once the flanges are bolted tight, there is no movement between them and the gasket is compressed solid. It cannot be damaged by forces acting on the pipework.

 

Hi Pete, was going to call you but seeing as you are online....

What is the benefit from changing from OEM up-pipe to Scoobysport one?
The OEM up-pipe looks as though it has changes in section throughout it's length which would pretty much bugger up any pulsing benefits assumed, but it also looks to be a lot smaller in diameter compared to the Scoobysport replacement. The smaller diameter will induce greater exhaust gas velocity compared to that of the Scoobysport bigger diameter.
Cosie Convert (I think!) posted some time ago qualifying this, saying that he felt as though it was laggier but improved flow with the Scoobysport up-pipe. Would this indicate that gas velocity had dropped but pulse energy was up????

Could you supply a technical explanation please Pete as I too am thinking of changing, but not if I will increase my Lag any further!

Cheers, Jacko.

 

Hi Jacko

You seem to have answered most of your own questions, but with regard to spool up, the entry into the turbo starts at 48mm and reduces down very small, to accelerate the gas. The gas arriving at the turbo inlet is at huge pressure and a stream of stable airflow will have far more pushing ability than a turbulent thinner stream.

Our up pipe is also 48mm diameter, than standard 92-00 is 41mm, the 01 up-pipe is 36mm.

 

Cheers 4 speedy reply Pete.
So in layman's terms you are saying, that the Scoobysport up-pipe will improve my Spool up?
Do you have any empirical data to confirm/deny?
Just need to justify more financial outlay to the missus...

Jacko

 

Jacko

Data....

An STi7 in standard form hits full boost at 4,000rpm.

Put a turbo back exhaust on an STi7, with the standard boost control restrictor and it will hit full boost at 3,200rpm but will over boost/spike to 1.5bar.

Put on an up-pipe as well and it still hits full boost at 3,200rpm, but will boost spike to 1.7bar.

Standard overboost (??? something wrong in those two words) is 1.3bar.

The STi7 uses the same up-pipe as a 92-00 car.

Before I start off anything else here, the boost spikes are easily and completely controlled by changing the restrictor size, so making the car safer than standard

 

 

Pete,

Does full boost after changing the restrictor with/without the U/P still arrive at 3,200rpm?

Ta,

Matt

 

yes

 

ta

 

Thanx

 

Being from Florida you should know about the usuals: Godspeed, PDE, Vishnu?

Its good to see what people across the pond are using though.

Brian

 

I've had the Scoobysport uppipe on for a month now. I'm running 1.7 bar boost. EGT of 800 deg C and doing a bit of drag racing with it.

No problems whatsoever. Turbo spool up is also improved, my TD05 is producing over 1 bar at 2500 rpm. Full boost of 1.7 is showing by 2800 rpm.

 

Whatever uppipe you decide on make sure you you put a straight edge on the flanges BEFORE you install or have the uppipe installed. If it not almost perfect return it for another one.
An uppipe leak is a major PITA because of the labor cost and new gaskets required to correct it. Trust me I know.

Matt

 

Andy,

I've just read that with your TD05 you are reaching full boost ..... 1.7bar at 2800 rpm. At how many rpms do you actually feel the engine producing boost, I ask this because sometimes it is possible to have boost at certain RPM's but you this boost actually hits you later on. With my VF 24 I could see 1 bar at 2800rpm but I actually felt boost around 3100~3200 rpm.
Also looking at a picture of your engine it seems like your air inlet hose is much wider than anything I have ever seen .....

Carlos H.

 

Andy, in fact were have u place the power steering pump ?????


Carlos H.

[Edited by carlos_hiraoka - 6/27/2002 10:27:50 PM]

 

he has removed the power steering..

inlet 90mm I stand to be corrected..

David

 

Inlet 75mm ID (90 OD so you'll pass David ) Power steering is a girly thing

The RPM that the boost 'hits' depends which gear I'm in. There is a slight delay between boost rising and power rising, this I assume is due to my somewhat crude method of boost control (dawes type)

On my last dyno trace (before the uppipe and turbo inpipe), the torque was approx 300 rpm behind the boost. I had 1.5 bar at 3300 rpm with 180 lbft torque. At 3600 rpm I still had 1.5 bar boost but torque had leapt to 335 lbft

As the exhaust backpressure rises whilst spooling the turbo, this delays the power. Ideally the wastegate would start opening a bit earlier to let the engine breath at the expense of building more boost pressure.

I may try a bleed valve instead of a Dawes type valve just to soften the rise a bit.

On the road this is not really noticable unless I give it full throttle in top from very low RPM. Normally the RPM rises much quicker than on the Dyno, this 'kicks' the wastegate open sooner and there is no detectable delay in torque following boost.

The uppipe and inpipe have not really changed this characteristic but they have brought the boost/torque rise points further down the RPM scale