STi Time Attack 2008 - new dyno figures !!

gary@apt · Post by **gary@apt** » Sat Sep 13, 2008 7:54 am

dunc confused why did car have nearly 85bhp of transmission lose on old run and only 40bhp on new one???

duncan · Post by **duncan** » Sat Sep 13, 2008 10:43 am

gary@apt wrote:dunc confused why did car have nearly 85bhp of transmission lose on old run and only 40bhp on new one???

So am I

449 whp was quite a surprise when it came up on the screen.

When you backed to backed yours on your dyno and clive's dastek - what were your findings?

duncan · Post by **duncan** » Sun Sep 14, 2008 7:05 am

Picked up one of these on friday to give more roll stiffness.

The existing whiteline 22mm ARB's are set to hardest setting and more headroom in adjustability is needed. The Perrin 25mm rear bar will give that option. A front 25mm will be added shortly to add the ability to tune that end further.

It will go on the car today :thumb:

duncan · Post by **duncan** » Sun Sep 14, 2008 8:37 am

duncan wrote:
gary@apt wrote:dunc confused why did car have nearly 85bhp of transmission lose on old run and only 40bhp on new one???
So am I

449 whp was quite a surprise when it came up on the screen.

When you backed to backed yours on your dyno and clive's dastek - what were your findings?

I will be running it at Gary's next saturday on the current map to see how the different dynos compare. Would be amazing to reach 449 whp on the dyno dynamics rollers. That would comfortably see it over 500 at the flywheel using the DD flywheel extrapolation. We will see.

duncan · Post by **duncan** » Sun Sep 14, 2008 4:23 pm

Perrin ARB fitted along with Stout Mounts - feels really good and flat whilst cornering although front is still leaning a little. Front kit to go on soon :thumb:

duncan · Post by **duncan** » Sun Sep 21, 2008 9:34 am

Had this on the dyno again yesterday at APT to see whether map changes had made the difference.

It was a dyno dynamics dyno this time so difficult to compare with the Dastek at Zen but nice to see that it produced 489.7 bhp and 490+ lb/ft there too. Again, this was on unboosted fuel.

I also took the opportunity to pick up some BioEthanol from the local Morrisons at 107p a litre ....not bad for 109 octane fuel I thought. Filled a couple of Jerry Cans up for luck.

I tried an initial run on this on the dyno but it was not mixing properly so would range from being lean to rich but running this at a 10% mix for starters to act as an octane booster.

Will be going to a 20-30% mix this week as that is about all I can get away with on the injector sizes I have it at present with the extra fuel that is required for BioEthanol.

I believe it will take a lot more timing with this fuel than std pump fuel in a similar way to Methanol and it smells funny .. cool

Post by **Stuart** » Sun Sep 21, 2008 10:23 am

Nice figures Dunk

by way of comparison, how did the figures at the wheels come out?

449 vs?

duncan · Post by **duncan** » Sun Sep 21, 2008 10:50 am

No idea Stuart - I will get the graphs from Gary on monday but I am guessing at less than 449

:lol:

Ultimately it is pleasing that the flywheel figures are similar from Zen's to APT's but it has highlighted some significant issues with taking it further from here with respect to the limitations of the ecu and the repeatability of runs to judge changes. It was just not possible to get two runs to come out the same yesterday due to timing, afr or *other* factors in there. The sooner I go speed density the better to regain control of the key elements of the runs to be able to see the instant effect (and real-time effect) of changes.

Cams would help the situation above 6000 (which is where it drops) but they are substantial wonga and not going to happen in the short to medium term.

In the short term, I will be experimenting with cam advance to see where gains (if any) can be made with this and setting it up right on the bio mix.

Post by **Stuart** » Sun Sep 21, 2008 10:59 am

Sounds interesting. Like you say, flywheel figures are close enough between the two so there is some parity. The wheels figures were more about working out losses and the calculations used between the two.

I do not understand (or want to) the inner workings of mapping but ultimately more control over a map should give better results. I have questioned how far you can go with a flashed ECU for ages, as our old MSN conflabs used to prove. It looks like you've shown what you can do on basic fuel.......the bio thing seems to be different again, so at least you can amuse yourself with more tinkering in that regard.

Cams are all well and good, but where exactly do you want to draw the line? Do you still intend the car to be your work hack next year or have the scales tipped into making this a dedicated track car? If that is the case (DTC scenario) surely there would be better results from getting the car more focused in terms of weight loss, rather than more power and more related stress?

Onwards and upwards in any event :thumb:

duncan · Post by **duncan** » Sun Sep 21, 2008 11:22 am

Tinkering at the edges is about all it is really, plus a token gesture at being 'green' and 100% within the rules for TA. A proper ECU is on the cards but I am not sure on timing of it yet - this has always been needed to be fair but it has been nice seeing just how far it will all going on the essentially std set-up.

It is amusing to see Gary's impatience at any changes made to the map and the procedure to make the changes whereas an aftermarket ecu would be much quicker to set up and more repeatable.

Parity between the two dynos was nice, my own road dyno figures fall in the middle of the two for whp. Ultimately there are useful from a tuning point of view and the information from yesterday will take it forward (even on the std ecu)

DTC Very good question Stuart. The answer is that it really depends on what the classes are in Time Attack. If (and it is a big if) there is a 'street' class, then I would love to keep it as a road hack and prove the point in that class. That would suit me better as I have no intention of losing a car to the track completely as it is still so much fun to drive on the road. If that isnt the case, then some creature comforts can be stripped out of it. In short ... I'm not making a decision right now