Bruntingthorpe Test day ?

RATS' Racer off to Blyton Park today for some tracktime.I fixed the throttle cable issue by making a new one from scratch.New OE/Simon ones are not the best ........
Time for more tests...mainly concerning engine bay heat issues .Will be taping bits up and taking bits off .

A lot of data for Steve to collate - all cars weighed with driver, power runs have to be put through a formula with the weight. From memory, - Dave Miles 3.0 twin turbo 4.5 0-60, 10.4 0-100, 13.0 @ 112 1/4 mile. Remember Brunty is up hill. As a guide Mark Garners auto Clio Trophy ran 6.3 - 0.5 sec slower than factory and 1/4 mile will be even more affected. I used to do a fair bit of drag racing years ago and reckon Daves car would run at least 12.4 at Santa Pod with that terminal. Lee ran 4.6, Faulksy 4.8 and John Law 5.0 dead. Lees car much lighter than anything else, Faulksy pipped Dave Miles car by about 8 bhp as most powerful car, but Dave is running 1/2 the boost to be fair. Think John held on to top speed with 158 mph. My injection was slowest lol.

Hope that wets your appetite :0)

[mettersl]

Looking forward to the results..sounds like excel will be needed!
And of course, your injection still has more than my atmo...

[stephendell]

Apologies for the delay. Friday / Saturday was white car MOT and set up for Crystal Palace. And I'm at the show today. Hopefully will get my act today tonight and yes it will be an excel sheet lol.

As stated before it looks like the weight difference kills the 610 performance even with tuning. So much more extra power is needed to overcome the weight. The results may surprise you. From the results wondering if there might be aerodynamic issues also.

.
Might be worth doing a split at 50mph, you've got the 0-100, do a 0-50, as aero effects up to 50 / 55 mph are pretty negligible, and that should show another trend point between GTA / A610 characteristics. Tyre losses dominate up to 50mph, why truck fleet companies are more concerned about tyre losses than aero in terms of fuel savings...

Also begs the question if the design team members for the GTA and A610 were largely the same, or significantly changed, as the design parameters and what mattered probably changed as well in that period... interesting...

Sounds like a good day, the 610 is a mile muncher in comfort, If there is another day my GTA should be finished by then but have no idea what Hp it will be putting out, but nothing will beat the V8.

Hmmmm ?
Not so sure myself.Getting that power to stick may be an issue + breakages in drivetrain


Where's that Dell boy got to

I'm looking into ways of limiting the power to @ 400 bhp in the 1st 2 gears, bit like they did with the 21 Turbo to try and give the drivetrain an easier life. Realistically it's hard to get any car with a manual gearbox much under 4.5 secs but should be phenomenally quick once hooked up. Was encouraging to see how the 300bhp cars put down that power with so little drama.

In low gears the car accelerates quickly into the next gear.
In higher gears it has all that power and torque driving through it for longer in each gear.
In my mind, Transmission stress is higher in high gears. This is why you feel a slipping clutch in 4th and not so much in 1st.
I understood that cars that limited power in 1st and 2nd were to limit the wheel spin only, which is a different issue to transmission loads.

[BIG_MVS]

https://www.youtube.com/watch?v=sO_OFfoxmgU

[stephendell]

Here are the collated results.

Best result for each category.

Bruntingthorpe Results August 2017.pdf

Bruntingthorpe 2017.png

[stephendell]

Some notes.

Car weights include driver.

1/4 miles times are slightly slower than drag strip due to 1 foot rollout, surface and slight incline. 1/4 mile terminal speeds more representative as traction not taken into account. The fastest cars would likely have achieved high 12s at Santa pod or similar.

Tony Law's car was driven by John Law for performance testing. Full vmax not attempted due to obstruction on runway.

Jon Butterworth added 12.5 gallons of fuel mid testing. Weight adjusted accordingly.

Tony Smith's car had no 5th gear hence Vmax not attempted. Espace injection engine.

Lee Crowston. Full vmax not attempted.

Mark Garner's on board Renaultsport monitor gave times approx. 0.1s faster than the Racelogic equipment.

Terry Staines' car was driven by Lee Crowston for the 0-60 & 0-100 results given.

Very interesting the GTA files with a good power to Wt over 300bhp and not much point with it having much more as stated earlier as to get below 4.5s in a manual is hard, and this would see off most cars on the road.

Interesting to see the power outputs now they are adjusted. I reckon Dave Miles' car can't be lighter than my car - I'm only 5kg heavier than him and his car has lots of bits in than mine hasn't. I did have about 10 gallons of fuel though but still?

In low gears the car accelerates quickly into the next gear.
In higher gears it has all that power and torque driving through it for longer in each gear.
In my mind, Transmission stress is higher in high gears. This is why you feel a slipping clutch in 4th and not so much in 1st.
I understood that cars that limited power in 1st and 2nd were to limit the wheel spin only, which is a different issue to transmission loads.

Torque is multiplied in the lower gears though Simon must twist harder to make you accelerate faster.