Car Climbing Out Of The Dyno - Advice?

[MBS206]

what am i doing wrong?...ive got a r32 running around 145 MPH weighing 1571kg...its got over 600kw at the treads.

Take the dead bodies out of the boot... Might shed a few kilos...

How do you have a fully stripped car weighing so much?

Also, to the dope asking if you double your torque will you accelerate twice as fast... Basically, YES.

Torque = Force x Distance.

Keep distance constant, double your torque, you had to double the torque.

Acceleration = force / mass.

From the above formula force just double, your mass has remained the same, therefore your acceleration just doubled.

So long as you put the power to the ground (And we weren't debating that, you were debating power figures VS MPH/ET)

A car that reads 400KW @ 10 000RPM HAS to be slower at its peak power rating (In terms of acceleration) compared to a car making 400KW @ 5000 RPM when it is at it's peak power rating... The 5000RPM car is pushing down double the torque!

[topher_]

hehe... had to think about what a black dyno was for a second there

I will take it to the strip when I get a chance...

Would low 11s be possible in a 32 rb30det with 300 odd rwkw with propper suspension set for drags and a pair of semis god and warmed up? I have a fairly consistant launch and usually pull a sub 2 60 foot time.

for a comparrison i ran a 12.1 at 103mph full street trim on tyres that were pretty much down to the wires and d2 coilovers. I think my 60 ftr was 1.64 or 1.74 or something that was also with 300rwkw so i am guessing with some decent tyres id probably just get into the 11's. Your car will be making more torque than my 26 though

[PM-R33]

That's some quick 60 ft's for D2 coilovers and shit tyres

Edited October 4, 2009 by PM-R33

[Swiper the Fox]

Take the dead bodies out of the boot... Might shed a few kilos...

How do you have a fully stripped car weighing so much?

Also, to the dope asking if you double your torque will you accelerate twice as fast... Basically, YES.

Torque = Force x Distance.

Keep distance constant, double your torque, you had to double the torque.

Acceleration = force / mass.

From the above formula force just double, your mass has remained the same, therefore your acceleration just doubled.

So long as you put the power to the ground (And we weren't debating that, you were debating power figures VS MPH/ET)

A car that reads 400KW @ 10 000RPM HAS to be slower at its peak power rating (In terms of acceleration) compared to a car making 400KW @ 5000 RPM when it is at it's peak power rating... The 5000RPM car is pushing down double the torque!

i have removed the rear seat, boot trims, A/C and stereo...everything else is still there...its not as 'stripped' as a lot of people think. Add into that the weight of the cage and other associated safety items and its no featherweight. I built the car to comply with the ANDRA Sport Compact street class rules and they were quite strict in keeping the entrants genuine street cars. Anyway i like my carpet, power windows, sound deadening, factory controls, interior trims etc. stripping it fully would make for a pretty awful car to drive on the road.

its been a while since ive looked in the boot for stowaways so i might have a squizz and clear them out.

Edited October 4, 2009 by DiRTgarage

[PM-R33]

Oh really is still has a full interior, power windows, sound deadening etc. Fair enough than, makes sense now.

[DCIEVE]

Take the dead bodies out of the boot... Might shed a few kilos...

How do you have a fully stripped car weighing so much?

Also, to the dope asking if you double your torque will you accelerate twice as fast... Basically, YES.

Torque = Force x Distance.

Keep distance constant, double your torque, you had to double the torque.

Acceleration = force / mass.

From the above formula force just double, your mass has remained the same, therefore your acceleration just doubled.

So long as you put the power to the ground (And we weren't debating that, you were debating power figures VS MPH/ET)

A car that reads 400KW @ 10 000RPM HAS to be slower at its peak power rating (In terms of acceleration) compared to a car making 400KW @ 5000 RPM when it is at it's peak power rating... The 5000RPM car is pushing down double the torque!

Might be making yourself look like the dope there chief. What is power? Work done. You can have all the torque in the world and go no where if no work is being done. Accceleration is the result of work, obv torque is directly related to speed and power. Two cars with identical power are accelerating at the same rate for the same mass, one car cannot accelerate faster without doing more work (power) than the other.

In reality the car with the highest average power will be quicker. If the gearing is right the car having that power at higher rpm (ie less torque) will likely be quicker given traction limitations assuming the same average power/weight etc etc.

[R31Nismoid]

for a comparrison i ran a 12.1 at 103mph full street trim on tyres that were pretty much down to the wires and d2 coilovers. I think my 60 ftr was 1.64 or 1.74 or something that was also with 300rwkw so i am guessing with some decent tyres id probably just get into the 11's. Your car will be making more torque than my 26 though

103mph with 300rwkw?

That is wrong, MPH is WAY too low.

[MBS206]

Might be making yourself look like the dope there chief. What is power? Work done. You can have all the torque in the world and go no where if no work is being done. Accceleration is the result of work, obv torque is directly related to speed and power. Two cars with identical power are accelerating at the same rate for the same mass, one car cannot accelerate faster without doing more work (power) than the other.

In reality the car with the highest average power will be quicker. If the gearing is right the car having that power at higher rpm (ie less torque) will likely be quicker given traction limitations assuming the same average power/weight etc etc.

Go back to physics...

Nuff said.

If you have one car at 4500RPM at the same time of second car at 9000RPM, making the same power, in identical styled cars (Well hey, we are attempting to compare what Skyline A and Skyline B did, so changing gearbox is just something you can't do in this comparo) then the car turning at 4500RPM is CLEARLY going to leave the other car for dead... It's making double the torque. Double the acceleration (Remember, comparing one skyline to another, you need to be keeping the gears etc the same).

But you were close on the highest average, but it's actually the highest average TORQUE that will be the winner.

HP wins bragging rights at the pub.

Torque wins races... (Torque at the wheels BTW... )

[DCIEVE]

Go back to physics...

Nuff said.

If you have one car at 4500RPM at the same time of second car at 9000RPM, making the same power, in identical styled cars (Well hey, we are attempting to compare what Skyline A and Skyline B did, so changing gearbox is just something you can't do in this comparo) then the car turning at 4500RPM is CLEARLY going to leave the other car for dead... It's making double the torque. Double the acceleration (Remember, comparing one skyline to another, you need to be keeping the gears etc the same).

But you were close on the highest average, but it's actually the highest average TORQUE that will be the winner.

HP wins bragging rights at the pub.

Torque wins races... (Torque at the wheels BTW... )

I hope your not designing powertrains! You have failed to address the basic things I have commented on (physics if you will).

Here is a handy link, you may learn a thing or two - pay particular note to the force at the wheels calculations.

http://craig.backfire.ca/pages/autos/horsepower

Edited October 4, 2009 by DCIEVE

[topher_]

103mph with 300rwkw?

That is wrong, MPH is WAY too low.

Might have been 107 mph i can't remember exactly but my first run was a 13.4 at 113mph

edit: yeah i was way off lol these were my times

1st run i ran a 13.4 @ 113mph 2.38 60ft

2nd run was a 12.3 @ 109mph 1.86 60ft

3rd run i ran a 12.1 @ 108mph 1.74 60ft

1st time at the track and had only owned the car for a month aswell

Edited October 4, 2009 by topher_

[SimonR32]

Go back to physics...

Nuff said.

If you have one car at 4500RPM at the same time of second car at 9000RPM, making the same power, in identical styled cars (Well hey, we are attempting to compare what Skyline A and Skyline B did, so changing gearbox is just something you can't do in this comparo) then the car turning at 4500RPM is CLEARLY going to leave the other car for dead... It's making double the torque. Double the acceleration (Remember, comparing one skyline to another, you need to be keeping the gears etc the same).

But you were close on the highest average, but it's actually the highest average TORQUE that will be the winner.

HP wins bragging rights at the pub.

Torque wins races... (Torque at the wheels BTW... )

people who use the phrase "torque wins races" usually have no idea in the world what torque is...

you prove this point

[bubba]

103mph with 300rwkw?

That is wrong, MPH is WAY too low.

I ran 103mph with only 250rwhp, ET was 13.9 with a 2.3 60' (no traction in 1st and most of 2nd)..

Anyway, kinda back on topic.. I'm in the same boat as TiTAN (RB30DET, GT35R) and hoping to make 500rwhp.. should I throw on the old hard rubber I have lying around?

[FineLine]

I ran 103mph with only 250rwhp, ET was 13.9 with a 2.3 60' (no traction in 1st and most of 2nd)..

Anyway, kinda back on topic.. I'm in the same boat as TiTAN (RB30DET, GT35R) and hoping to make 500rwhp.. should I throw on the old hard rubber I have lying around?

Yes you should throw on your old hard rubber. federal RS-r's will not cut it on a prolonged dyno session. I have watched mine turn to molasses.

[Guilt-Toy]

sold haha.

I had mine tuned ages ago and at the time it only had 250ish kw, but it was strapped down with NUMEROUS straps. Anyone who has been to the PITS knows the top notch setup matty has going on there.

Pluss I would think that it would have to be strapped down WELL due to OH&S requirements. I dont care who you are, not strapping a car down, or just using 1 strap is completely negligent.

Can you please get some pics and some info on this strapping method, on the DD dyno we have here in Georgia (Unigroup Engineerings old dyno) with my car on it i cannot stop the wheel spin at all. I am strapping it the same i did on other previous DD dynos and there was no wheel spin but now here.. its driving me crazy!!!

No it's not... Head out to WSID...

Maybe a car making 480RWHP at 9000RPM it is...

But if it's pushing 480RWHP at 4500RPM... You're making double the torque... IE, it'll accelerate twice as fast...

Edit: As to that video of the car "climbing" out of the dyno... I wouldn't even call that movement if you'd seen how mine used to walk around when coming on boost until we worked out how to strap it on perfectly...

Car used to walk 1.5Ft sideways, and if it didn't go sideways, it'd climb OVER the front of the roller and nearly touch the front of the dyno... Oh, and the whole time it's doing this it's filling the work shop with tyre smoke...

Took us a bit to work it out, but lower the ramp rate, and we actually LOOSENED one of the straps to stop it wheel spinning so much... Still shredded the tyres though in the end... And they were just normal streets!

What way was it strapped? and what ramp rate did you end up using?

probably leaving it in 3rd

lol!! Sorry Mr Dirt but that made me laugh

[mad082]

maybe the rollers have been contaminated with oil or something like that. maybe try giving them a quick wash with metho

i'm just pulling ideas out of my arse though.

[bubba]

Yes you should throw on your old hard rubber. federal RS-r's will not cut it on a prolonged dyno session. I have watched mine turn to molasses.

Cheers

[topher_]

That's some quick 60 ft's for D2 coilovers and shit tyres

Ye i got defected on the way back from heathcote because you can see the wire coming out the tyre 1.74 was my best 60ftr

Edited October 6, 2009 by topher_