Page 1 of 139

STi Time Attack 2008 - new dyno figures !!

Posted: Sun Aug 12, 2007 10:39 am
by duncan
Following on from my main project:
http://www.bigpower.co.uk/forum/viewtopic.php?t=157

and my Time Attack preparation project:
http://www.bigpower.co.uk/forum/viewtopic.php?t=3546

I thought I would start a new project thread for the next phase of developments on the car.

Currently the car is pretty much sorted apart from a few issues that have reared their head now that it is slightly quicker (or I am) on track and in the light of a sit down and review of the current performance against others in Time Attack.

Current Issues that I am aware of:

1) Fuel Surge .... about time really, I was feeling left out from the Subaru community by not having had this to any extent :) - now I get it on high G right handers and is a cause for concern that needs solving.

2) Body Roll .... having looked at pictures of me, I feel that a little less body roll will help the handling on the limit on track

3) Power .... more is almost always good

Solutions:

1. Fuel Surge

There are a number of solutions to this issue that plagues all Imprezas (it is in the mfr's handbook of excuses) and is down to the design of the fuel tank. The option is not there to change the tank so I am looking at ways to improve fuel pickup from within the tank by using an anti-surge tank or swirl pot. Hyperflow do a good kit for this that retails at

Posted: Tue Aug 14, 2007 5:18 pm
by duncan
Fuel Surge Solution has been chosen:

Image

[quote]HyperFlow Technologies has completed development of a fuel surge tank to suit the MY01-05 WRX and WRX STi fuel pump assembly.

It is recognised that fuel surge does occur with light fuel loads in the Subaru WRX, leading to starvation. This shortens range on the track and adds mass to the vehicle, with unnecessarily high fuel loads for Super Sprints and track racing.

The Fuel surge tank has been developed over many months to ensure the materials and configuration are durable and perform.

A custom thermoplastic base has been created from fuel resistant materials. The base interfaces with a CNC machined billet alloy top plate that is fixed to the fuel pump frame

As shown in the images above, the base of the surge tank fits precisely to maximise use of fuel in the tank. The baffle system has been successfully tested on an STi at Wakefield Park clocking consistent 1.09 sec lap times with light fuel loads

Posted: Tue Aug 14, 2007 5:35 pm
by Stuart
Bearing in mind your exhibited talents with oil changes, I should imagine blind folded neuro surgery may be simpler.

Good luck. Get a pro to do it :thumb:

Posted: Tue Aug 14, 2007 5:51 pm
by duncan
I will have a pro's telephone number handy :D

Posted: Tue Aug 14, 2007 6:07 pm
by RX7
Ha ha ha good one Stu.

Looks good though Dunk, make sure you take pics of the work !!

Posted: Wed Aug 15, 2007 12:42 pm
by duncan
Well it has arrived at the bargain price of

Posted: Wed Aug 15, 2007 1:02 pm
by blacky
Ooh Dunc, thats proper decent, do you know if they do ones for a Classic tank :?: :?:

As I have teh same issue, and have to run with 1/2 tank all the time.

Posted: Wed Aug 15, 2007 1:15 pm
by duncan
Unfortunately they only do one for 01 onwards :(

RCM may be able to advice whether a different solution exists unless you want to go down the road that Bob Rawle did.

Posted: Wed Aug 15, 2007 2:40 pm
by duncan
hmmm - not what I ordered ... bugger.

Posted: Wed Aug 15, 2007 2:57 pm
by Gerry H
That doesn't look very big. What's it's capacity?

Also it doesn't look much for nearly