So thats what a 300 bhp+ GTA goes like!

Just back from the rolling road - what a day! Had a few problems, my plenum chamber (turbo side) split along the join where it was cut and shut and we had to quickly fabricate a temporary replacement and my boost controller was doing weird things - not helped by the fact I couldn't remember how it worked since its been 3 years since I've tried to use it! Then the guy mapped it using his own wide band lambda read out as the one on the Adaptronic didn't appear to read any signal. Power signs were promising straight away with the car making about 150 bhp at the wheels by 3000 rpm at standard boost. We then set the boost to 1.2 bar but the boost controller kept doing weird things so we settled on a bar where there didn't seem to be any problems. By 5000rpm the car went off the scale of the rollers (240 bhp at the wheels) with power still climbing significantly. We went out on the road to map the last 1000 rpm or so with me driving and encountered a mysterious misfire under load. On returning to the workshop and checking the spark plugs it was found to have Megane 1.4 plugs in. These were the plugs in it when I bought the engine brand new so whats gone on there I have no idea! Back out to map it and the car went better with the new plugs and the car needed approx 15-20 percent more fuel to keep the same air/fuel ratio over the last bit of the map (the guy said this should equate to a similar percentage power increase). It could still do with a little fettling, the idle speed hunts a bit and it does occasionally mis-fire for no apparent reason but blat it hard through the first 3 gears and FLICKING HELL its rapid. It wasn't until I got of the motorway coming back and on to the country that I realised just how quick - its absolutely awesome in the 3-5000 rpm range which is ideal round the lanes near me - and quicker than my Skyline I reckon too, although I think that would still have the edge in a flat out sprint but I'm sure it would be very close. Unfortunately it was a fairly low spec rolling road which didn't have the facility to print power curves etc but the guy down there was excellent and fantastic value - 6hrs ish on the rollers £200!! I'll try and get it on Abbeys Dyno-pack if they don't want to rape me and get some graphs.

I doubt you will have your mind on work tomorrow Tony.
AWE-SOME, I'm sure with a bit more fettling you will squeeze a bit more out of it.

What next? are you going to do a bit of sprinting in it?
How about a few laps round Goodwood on 19th August?
I have some other dates for Cadwell Park, Loton and Lydden too.

Excellent...240 @ the wheels is good going....Ive got something to aim for when I put my poor engine back together and get the bigger turbo!
What torque figures did you get?

Unfortunately the rollers were only reading bhp - no fancy graph plotting etc so only have the maximum figures - it has more than 240 at the wheels though (that was the maximum power the rollers could read) - that figure was at 5000 rpm with the power still climping - the guy mapping it reckoned it had about 15% more than that judging by the extra fueling required between 5-6000 rpm when taken out on the road (also air temp was 20 degrees hotter on the rollers than on the road) so more in the region of 270 at the wheels. Did a few in-gear acceleration runs on the way back 80-100 in 5th - 6sec and 70-90 in 4th 4 seconds.
I think the power curve will be a totally different shape to yours though Pete, has no appreciable step in the power band - almost drives like an atmo and pulls hard right to the red line. He hardly touched the ignition timing so I think there are plenty of gains to be had. Like you I'm over budget so will have to wait til next year now to get it perfect, but my drive home this afternoon was the most enjoyable I've had in a very long time.

He's as happy as a dog with two dicks

Those times do tie in a bit quicker than the A610. It would be good to put your car head to head with Joe's A610 as a comparison, as he's running a bar of boost too.. though the GTA is a fair bit lighter..

Shame you couldnt get any plots..

He's as happy as a dog with two dicks

And I'm very happy for him

"the guy" is Mike at Cyclone Motorsport in Wickford, who despite having a pretty old rolling road, clearly has a lot of experience and did things with both Tony's and the TT DeLorean that've had me shrugging for weeks.

The top end of the scale was 260 not 240 (I seem to rememeber, but just for a change, am couple of beers shy of sober and this post is becoming very tough to type coherently.......... damn that's a tough word to type....)

I thought Tony's car was fast when we went out in it the other day. Now it's a testament to anyone who says 300hp is not very powerful. Tony also left out the bit about the power climing so fast that the car actually kept spinning the wheels on the rollers at full boost.... at 1 bar. His turbo can easily exceed that.

The blown turbo pipe was quite a bang.... I'm glad I had my fingers in my ears

Well, at least you can work out that at 5000rpm, your torque would have been 250lb/ft...

EDIT : Yes, Ive just worked it out, you must have about 260bhp at the wheels max, maybe 250.. Good going.

Torque only 250lbs.....surely some mistake if his power was also 250??
Slipping on the rollers just means he needs to get them grooved....mine slipped on them the first time I got mine on a year ago and it only had 160 at the wheels.....he has grooves in the rollers now and can handle 400bhp.
My power curve will be flatter once Ive got the turbo to match (and an engine )....the fact that it had run out of capacity was wobbling and had a chunk of one blade missing wont have helped!!!!

Torque only 250lbs.....surely some mistake if his power was also 250??
Slipping on the rollers just means he needs to get them grooved....mine slipped on them the first time I got mine on a year ago and it only had 160 at the wheels.....he has grooves in the rollers and can handle 400bhp.

Nope,you can work it out, and some other stuff...(this is torque at that rpm Pete, not peak torque..)

BHP is torque x rpm / 5252.......So 250 x 5000 / 5252 = 238bhp, close enough to 240....

Also, from this you can work out that at 4500, torque would have been 275-280lb/ft maximum (depends how steep the curve is), any more at it would have topped 240bhp again...

Nice one Tony Would love to see your times down the drag strip

Torque only 250lbs.....surely some mistake if his power was also 250??

Still probably a touch more torque than an F1 car makes! Actually a current F1 car with the V8 is probably a pretty identical match to a standard GTA in terms of torque.

Back to my point that power is all about where that torque curve is in relationship to the revs.

I would say its making peak torque somewhere around 3300-3700 rpm this is where it feels like its pulling hardest but as I said its feels very linear, I will try and get it on some rollers with plotting facilities in the next couple of weeks