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BW91/79 Single Project


GlennK
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I need another dyno station to check - before I take a large hammer to that turbo setup. Rapidly getting p**d off with this.

 

It's taken a lot of effort, time and money to get nowhere :badmood:

 

Your saying its the turbo setup doing it? A proven turbo kit that is known to work?

What exhaust are you running? What diameter is it? Have you done a compression and leak down test?

Edited by Paul Whiffin (see edit history)
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Your saying its the turbo setup doing it? A proven turbo kit that is known to work? = "I know the BW91/79 will happily make over 650 whp as others will state." as per my earlier post.

What exhaust are you running? = Posted in the members Exhaust Noise register; Apexi double decatted

What diameter is it? 3 inch

 

Have you done a compression and leak down test?

Not for 3 years (it was perfect then) unless you did one when you fitted the BW turbo kit and 264 cams setup last year?

 

I can accept that there's some loss from (i) Tyre slip on the dyno, (ii) autobox and drivetrain losses, (iii) inlet manifold restrictions but these don't seem to add up to a big difference in power to other BW setups.

Like I said I need to find out if it's just I had a bad day at SRR Dyno Dynamics or there's something causing a big power loss....open to answers.

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Not for 3 years (it was perfect then) unless you did one when you fitted the BW turbo kit and 264 cams setup last year?

 

I can accept that there's some loss from (i) Tyre slip on the dyno, (ii) autobox and drivetrain losses, (iii) inlet manifold restrictions but these don't seem to add up to a big difference in power to other BW setups.

Like I said I need to find out if it's just I had a bad day at SRR Dyno Dynamics or there's something causing a big power loss....open to answers.

 

 

my intake is also stock

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Thanks Rob,

 

Just been on the phone to Paul Whiffen for some things to check. Very helpful - I'd not thought to check for a collapsed catback so I'll do that - it was on the car when I got it from Japan in 2008 so maybe it's had it. Other than that I need to see the SRR Syvecs log dump for wheel slip (there was a fair bit of burnt rubber odour around the place), TC slip, and anything else upstream from the drivetrain that might be off spec...could be a faulty BW unit but as it's only been used rarely over the year since it was fitted it's low on my list. I'd have thought a problem with the turbowoul dbe seen during the mapping sesson anyway.

 

But, frankly, 524rwhp at 1.9 bar is taking the p*ss.

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Thanks Jamie, but that's around 100hp less than what it should be though. I've just checked the exhaust - there's a back box that I can't check inside but it looks a bit battered from road humps...How can I check if this has collapsed?

 

And who's got a straight through exhaust I can have/borrow to see what diference it makes?

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Well, if not on the same dyno then Brian (Suprab) above had made 631bhp at 1.5bar, and IIRC LuxLuc's original setup made 650bhp around the same boost. And similarly, J_Boulton last made:

"The car went in running at 1.45 bar, making 654 BHP at the flywheel and 540 ft/lbs from when it was dynoed at SRR back in June. It came out running at 1.75 bar, making 593 BHP at the hubs with 479 ft/lbs on Tesco 99."

 

So, even discounting the TDI hub day results (700's) I'd still expect to achieve significantly better power gains running at 1.9bar - unless of course there's some restriction in the gas flow...

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You'll drive yourself mad if you think rolling road figures are accurate and comparablewith other rolling roads. A properly set up Roto-Test with proper correction factors *SHOULD* be about as accurate as any chassis dyno, but my real world experience of power figures from chassis dynos V the same engine on a "proper" engine dyno have shown most RR power charts to be ludicrously optimistic.

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Didn't Jamesy make 742hp on a 67mm at srr or was that tdi? Anyways the proof is in the pudding, how does it drive? Is it noticeably faster?

 

Again completely different setup, that was a precision billet 6765 dbb, greddy intake etc, i made 730bhp at the same dyno with the very same turbo, a BW 91/79 is no match for a billet Precision imo.

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Yep. Apples with apples. My dubious record is only due to having another dubious record of driving the BW harder than anyone else! And assuming the fudge factor over and above the manual box is really 20%. Dynojets already factor in a big scaling factor to get to the fly hp.

 

And it does pull better than Suprapod - in a comfy exciting way not the 'Oh Shit grip the steering wheel' way...

 

And yes, a bigger Batmowheel is indeed on the wish list for next year along with a decent plenum, high lift cams, adjustable lightweight pulleys, new valves, springs etc, 11.5J rears with 315s on them and a nice straight through exhaust system...

 

But - first things first - I need to get to TDI for a hub dyno soon to get a better understanding of what the current setup delivers.

 

And Jamie - thanks for putting a smile on my face with your earlier post :)

Edited by GlennK (see edit history)
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Sorry to hear your pain Glenn. But to be honest thats a big problem for supra owners - chasing numbers!

 

Any other forum a car running 650 odd hp would be dreamland. Because some cars are pushing big numbers everyone now thinks 'ahh im gonna get me some of that'. Its not that easy and sometimes people dont see the cash that goes on behind the scenes to make it happen.

 

Whats 'most' important is how fast it feels. How fast it drives etc. Chasing numbers is awful and is a road to disaster in most cases, ive done the same myself in the past.

 

Glenn you have a very powerful car that goes very well, try to be happy with it and most importantly enjoy that bad boy mate ;)

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A Dyno is a tool to safely map an engine and see that the changes you are making are an improvement. The final figure they produce will differ but from testing i will say that.

 

RotoTest and DynaPack Read almost identical!

 

Rototest and Dynapack Hub figures are always within 5% of a Dyno Dynamics Flywheel figure.

 

Getting a Real figure from an Auto is pretty much impossible if it is using a Torque convertor which is not locked. Hence why TDI wont normally dyno an Auto.

 

You cant compare an auto figure to a manual just like you cant compare a Dyno Dynamics to a Rototest.

 

Take back to Santapod and see the terminal improvements

Ryan

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