Dyno results
 

I popped down to Surrey Rolling Road on Saturday in order to see what sort of numbers the car is making. The car is standard (to my knowledge) with the exception of a new panel filter. On the whole I am very pleased, but there is one particular area that I am a little unsure about.

On the boost graph it peaks at 1.3 bar at 3,600 rpm, but then pressure steadily drops throughout the remainder of the run to 0.9 bar. Shouldn't the pressure remain more or less constant once it has reached the peak or is this the sort of thing I should be getting?

BHP/torque
Boost pressure
AFR

Whilst I don't plan to do any major mods to this car, Charlie (I think he is the owner of the rolling road) had a pretty infectious enthusiasm so a call to JGM to book a remap may be in order fairly soon.

Cheers,
R

You must be happy with that! :ok:

Getting Simon to re-map it will get things in line nicely. The AFR is a bit "wobbly" but as said, Simon will sort you out.

Very pleased as I was expecting tihngs to be a bit lower than that. How does the boost graph look to you with regards the pressue dropping off?

It does drop off without doubt, but it is nice and even. Nice and safe.

Simon will flatten that for you :ok:

Boost curve depends on the turbo fitted and supporting modifications.

i.e small turbos tend to get mapped for a big bang in the mid-range, then tail off at the top. If you do not tail them off, all they chuck out is hot air and act more like a hair dryer then a turbo. If they behave like this there is no benefit from the additional boost at the top end.

Keeping the curve flat to the top would also require additional fuelling. If the injectors are not sufficient enough then you can tail the boost off in the map to match the injector capabilities.

1.3bar tailing to 0.9 sounds like a Prodrive/PPP or mild ECUTEK map.

I was just about to ask is this a ppp car? :drive:

Thanks for the replies everyone, it helps to apply some knowledge to the numbers!
The car has the PPP so given what has been said it seems at present it is all doing what it should be doing.

That said, getting Simon involved to smooth out some of the details whilst achieving a bit more power and torque is a bit too tempting.

Good results that mate.

Steve

The standard turbo can't flow enough air to maintain the boost flat and does tail off, that is perfectly normal.. 1.3bar and tailing off is standard ppp :)

Mapped more like 1.45bar tailing to 1.2bar.. should make around 350~360bhp and 400lb torque once mapped.

The only minor concern (too strong a word but couldn't find another) is the ecu I would say has pulled some timing just before 6000rpm to 6400rpm hence the slight dip in the power curve.

The AFR fuelling graph looks normal for ppp and sometimes find with the ppp sports cat it is running slightly different fuelling to that picked up on the dyno.

Simon :)

They are still good results mate, and have exceeded the quoted PPP figures too.. A JGM remap will improve it again for sure and you wont regret it!.

Does the Hawkeye PPP run a sports cat. Talking to Lucky at the last meet he mentioned Prodrive didn't fit one as reckoned the flow was as good as a sports cat on the standard cat.

Could be wrong, but sure thats what he said.

no thats correct.. I meant the standard cat..

I typed some of my reply thinknig it was a 2005 sti, then looked at the graphs to see the torque and the 57 plate lol..

Simon

LOL I done the same lunchtime, typed the answer assuming it was a TD04 based on boost, then read is was a 2.5 STi.

Nice one mate, you can't grumble at that

I think it was the case that whilst the standard cat wasnt quite as good as the sport cat and still restricted it a bit, it was still more than sufficient, and I believe it was also to stop the car producing more power (they obviously knew about the chocolate pistons :lol:).

Thanks Simon, chances are that I will be in touch soon enough to book some time with you.

That said I am reluctant to go down the route of changing any internals, but I am aware of the piston situation that can arise with Subaru engines. Assuming it were to be mapped to the sort of power as you mention above, is that still within safe tolerances of the engine and components, or would it also require some physical changes as well to stop things going bang?

Thanks,
R