Rolling Road Results

I took my car down to Surrey Rolling Road on Saturday.

How does this compare to other cars and is this decent power for my spec?

Also note that the car was very hot when we did the runs as id been sat in traffic for an hour on the M25 & M3 before i got there

http://www.laserlines.com/supra/power/power.jpg

http://www.laserlines.com/supra/power/afr.jpg

http://www.laserlines.com/supra/power/boost.jpg

I was going to say it's a lot better than my car did there, then I noticed it's a hub dyno like Thor's one. They had a rolling road type dyno when I was at SRR last.

Im no expert but that seems a bit low to me, considering you are BPU+, even though it is an auto. I ran 330Bhp in 5th gear (instead of the usual 4th) due to wear on my tires. Im only BPU.

Id be expecting closer to 370-400 for BPU+ but maybe im the one being unrealistic.

Its not a hub dyno.

Im no expert but that seems a bit low to me, considering you are BPU+, even though it is an auto. I ran 330Bhp in 5th gear (instead of the usual 4th) due to wear on my tires. Im only BPU.

Id be expecting closer to 370-400 for BPU+ but maybe im the one being unrealistic.

These are at the wheel figures, not fly wheel figures!

Its not a hub dyno.

Looks like you were running pretty high boost levels on a couple of those runs (Black and green lines)

These are at the wheel figures, not fly wheel figures!

Erm...so was mine. When toyota quote the standard Bhp at 320 ish, is that at the wheel or fly?

Sorry Ian. I was getting my dyno charts mixed up.

 

Looks like you were running pretty high boost levels on a couple of those runs (Black and green lines)

 

Also isn't it going rather lean on a couple of runs?

Was thinking the same, are you running Hybrids? If so, then that is a little low TBH, what have you got to control the fuelling.

P.S. I can't see signatures before someone tells me that he has it all listed there....

Was thinking the same, are you running Hybrids? If so, then that is a little low TBH, what have you got to control the fuelling.

 

P.S. I can't see signatures before someone tells me that he has it all listed there....

95 Supra TT Auto, BPU+, FMIC, twin HKS induction, HKS Hypermax II's, HKS FCon, Bigger Injectors, HID's

cheers jake.

not sure if the turbos are standard or hybrids which was why we did the last run on a slighty higher boost to see if it made any more power or remained the same.

Its only using an old SAFC at the moment but it did have an FCON V fitted which i had removed for the moment as it was running very rich.

My injectors are red & Terry seemed to think they were Blitz 850's?

In Japan the car was worked on by Kansai Service?

i think ive got a couple of invoices from them at home, i might try and get them translated.

Erm...so was mine. When toyota quote the standard Bhp at 320 ish, is that at the wheel or fly?

Fly.

Looking good Ian. Mine is running 345 with only a thing or 2 different from yours, so sounds about right for BPU+ on standard.

What's your full engine spec??

I think you are supposed to dyno cars in the 1:1 gear ratio, which is 5th on a manual TT. Anyone know what the effects of dynoing in a lower gear are? Is it just more chance of wheelspin or a possible skewed result due to lower gearing - if so, why isn't the diff ratio taken into account...?

Good numbers btw. 850cc injectors on stock turbos though!

-Ian

Fly.

 

Looking good Ian. Mine is running 345 with only a thing or 2 different from yours, so sounds about right for BPU+ on standard.

 

What's your full engine spec??

Other the obvious of the HKS airfilters, ARC intercooler & bigger injectors i dont know what else its had done engine wise.

Ill try and dig out the Kansai Service Invoices to see if they shed anymore light.

http://www.laserlines.com/supra2/engine.jpg

Good numbers btw. 850cc injectors on stock turbos though!

Thats what i cant work out?

if they are 850cc? they're red, thats all i know

how do the AFR's look Ian? i haven't got a clue what im looking at!

If you are running 850cc injectors, then they aren't doing much for your AFRs. Can you safely control 850's with an SAFC anyway?

If you are running 850cc injectors, then they aren't doing much for your AFRs. Can you safely control 850's with an SAFC anyway?

Yeah but not on stock turbos or even hybrids. Far too overkill

Yeah but not on stock turbos or even hybrids. Far too overkill

That's what I thought, unless they changed the injectors for the VVTi 440's, which are a pinky red in colour. Wouldn't understand why though.....

Thats what i cant work out?

 

if they are 850cc? they're red, thats all i know

 

how do the AFR's look Ian? i haven't got a clue what im looking at!

Well, it's interesting as your AFRs show classic BPU behaviour. Stock everything with the boost wound up to 1bar+. The AFRs are fine, but don't go above 1.3bar as the fuelling will fall off dramatically to leanness. I wouldn't run over 1.2 on stockers anyway - not only for longevity but also as the gains are minimal.

It's a good set of graphs actually, with the back-to-back runs with different boost pressure. You can see that running 1.2bar over 1.1bar you get about 15 extra bhp, but 1.2bar to 1.3bar you see about +5bhp - really minimal gains. In fact I'd go so far as to say the increase in power is from leaning out the mixture from low to mid 11's on the AFRs, and not from running higher boost - the stock turbos are overheating the air so much by this point you aren't really getting any more power.

Back to those AFRs - you dip into the 9's running 1.1bar of boost, and get around 12.0's running 1.3bar. Odd eh? Not really, as when the FCD comes into play it clamps the airflow signal to the ECU just below 1.0bar of boost. Thing is, just below 1bar the ECU goes to 100% duty cycle on the injectors anyway - a sort of "crash mode" where it's thinking, "the boost is too high - not high enough to initiate fuel cut yet, but I'd better chuck in as much fuel as possible because this isn't right!"

So, you get the same amount of fuel at 1.0bar, 1.1, 1.2, 1.3, and whatever you are mad enough to run above that. At some point the airflow into the engine matches the fuel delivery in a way that gives you a good AFR, in your case around 1.3bar. Less than that, it's too rich. More than that, it's too lean. So if you are using an FCD on a BPU car, you may as well run 1.2bar of boost Providing your fuel pump is good enough to keep the fuel pressure up at 100% duty, that is.

Of course, the moment you start messing with airflow mappers this rule of thumb goes out of the window. This is where your car is odd, as it behaves like a BPU setup but apparently has gopping great injectors and an FCON Got a photo of the injectors...?

-Ian

Got a photo of the injectors...?

-Ian

I'll go out and take a picture now.

But appart from that my AFR's are OK?

Edit: ill have to take a picture later as i've just looked outside and its chucking it down!

I'll go out and take a picture now.

 

But appart from that my AFR's are OK?

 

Edit: ill have to take a picture later as i've just looked outside and its chucking it down!

Yes they are *sigh*

Again, I'd say stick to 1.2bar boost though.

-Ian

If it helps, my bone stock Jspec ran 250 at the wheels at SRR.

Yes they are *sigh*

 

Again, I'd say stick to 1.2bar boost though.

 

-Ian

Yea i will be, found out saturday that i was only running 1.1 at bovingdon etc as my boost gauge is over reading!

So it now runs quicker than it did at Bovingdon

If you find the injectors are too big I'll sacrifice my 650's as a swap

your car is odd, as it behaves like a BPU setup but apparently has gopping great injectors and an FCON

Do keep up.

I said 850's as the Blitz are red. They could be some other JDM that I havent come across.

AFAIK dynoing in a lower gear will give inflated power figures. Maybe wrong but think thats right.