Dyno/Rolling Road question

[spike]

Sorry lads if this is in the wrong section, and Im sure also this has come up before, but the search is wayy to general here, cant find what I want.

What gear do you run the DC5 in on a rolling road ? Is it 4th like you would with most 5 speed cars, or is it different with the 6 speed box ?

Cheers.

 

[Dc5Dub07]

Well unless you have your own rolling road, its the guys who are either tuning the car or testing its BHP that would worry about which gear its in.. And sure most performance cars are 6 speed anyways...

 

[TypeGRRR]

It varies from one rolling road to another. Check out the dyno graph thread, there's loads of graphs most of them stating the speed at max bhp, you can work out what gear it has been tested from that...

HTH

 

[macer]

Its also depends on if you have removed the speed limiter.
At my last rolling road day I had the only DC5 with the limiter removed but the tuner would only run mine in 4th to avoid any arguments, even though I knew the peak for my car would not be read by the RR unless run in 5th.

 

[spike]

Cheers for the replies lads. Macer, yea thats kinda why I asked, the limiter thing came up with me and a mate in a conversation earlier. He'd previously had his car dyno'd in 4th (limited), but the operator had said that dc5s cant always make their peak power in 4th, but unless it's de-limited theres obviously no point running it in 5th. His car no longer has the jap limiter and he's doing his next run in 5th gear.

Im getting the car dyno'd on saturday, theres a group of us actually, and I'd never heard this before. I'd like to know I was getting an accuate reading in 4th gear (standard ecu) so was just wondering what gear you guys had had your runs in.

Im just confused over the whole matter. Like why should it matter - if the dyno is configured correctly taking your cars ratios into account ?

 

[logik]

Been to a few RR's now and i have only ever run the car in 4th.

 

[LA-DC5 ITR]

Cheers for the replies lads. Macer, yea thats kinda why I asked, the limiter thing came up with me and a mate in a conversation earlier. He'd previously had his car dyno'd in 4th (limited), but the operator had said that dc5s cant always make their peak power in 4th, but unless it's de-limited theres obviously no point running it in 5th. His car no longer has the jap limiter and he's doing his next run in 5th gear.

Im getting the car dyno'd on saturday, theres a group of us actually, and I'd never heard this before. I'd like to know I was getting an accuate reading in 4th gear (standard ecu) so was just wondering what gear you guys had had your runs in.

Im just confused over the whole matter. Like why should it matter - if the dyno is configured correctly taking your cars ratios into account ?

so would the figures be down if its in 4th? anyone confirm or rebuff this ??

 

[logik]

The figures wouldnt be down in 4th Stu. Like lets say we hit 7900 RPM in second, third and forth gear. At 7900 lets say a standard dc5 is putting out 218BHP.

Well in 2nd, 3rd and 4th it should be putting out the same power at a given rpm ratio. It should be able to reach 218 at a given rpm ratio in the given gear.

Like as far as i remember, when we were at westward he ran our dc5's in 4th and we got between 95-103MPH.

 

[spike]

Well in 2nd, 3rd and 4th it should be putting out the same power at a given rpm ratio. It should be able to reach 218 at a given rpm ratio in the given gear.

Yea, that was my arguement with my mate. I think a lot of it was that he didn't get a great power figure - or so he thought. What kinda power did you guys make - stu and logik ?

 

[logik]

Well when we were there last time we only had our cars a few months and they were standard.

I made 216BHP and Stu i think made 217BHP.

I will have my exhaust and induction kit soon, so i will be eager to get it tested again. I hope to make a further 10-12BHP.

 

[macer]

The figures wouldnt be down in 4th Stu. Like lets say we hit 7900 RPM in second, third and forth gear. At 7900 lets say a standard dc5 is putting out 218BHP.

Well in 2nd, 3rd and 4th it should be putting out the same power at a given rpm ratio. It should be able to reach 218 at a given rpm ratio in the given gear.

Like as far as i remember, when we were at westward he ran our dc5's in 4th and we got between 95-103MPH.

The power would be down in some cases. If ya run my car on the Dyno on put back on the limiter the car would hit the limiter before peak power is reached, as best I can remember my car hit peak at 128mph in 5th gear

 

[logik]

The figures wouldnt be down in 4th Stu. Like lets say we hit 7900 RPM in second, third and forth gear. At 7900 lets say a standard dc5 is putting out 218BHP.

Well in 2nd, 3rd and 4th it should be putting out the same power at a given rpm ratio. It should be able to reach 218 at a given rpm ratio in the given gear.

Like as far as i remember, when we were at westward he ran our dc5's in 4th and we got between 95-103MPH.

The power would be down in some cases. If ya run my car on the Dyno on put back on the limiter the car would hit the limiter before peak power is reached, as best I can remember my car hit peak at 128mph in 5th gear

Agreed Karl,

But lets say the Rev limiter or the kmph limiter is in place. When they are released from the factory they are capable of 218BHP. This power is reachable at the rev limit band in all gears and not just the higher gears.

Sure if you begin to modify the car and the limiters are still in place, then you will not hit the max power capable at a given rpm. For example in your own car Karl, i think it made 254BHP on your second run at westward. You had it de-limited for the runs. You cant be getting lets say, 218 in 2nd gear, 225 in 3rd, 238 in 4th and then 254 in 5th. The engine wont go up in increments on a power band. Your 254 is achievable in the lower gears too.

Karl

 

[LA-DC5 ITR]

i got 216 on my 1st run and 213 on my second a few months later with the overly expensive J's intake fitted

if i put maxol in it i may see a small increase, im pretty sure it will go up once the exhaust is changed though.

 

[logik]

Ah close enough buddy . Yeah we will both see improvments if we get the exhaust systems in check. Odd you lost power after the J's Racing Intake kit was fitted.

 

[spike]

Be interesting to see what I get saturday so. Neither of you guys have kpro have you ? My mates was a good bit down on that power actually..
What whp and torque did you both make ?

 

[macer]

The Problem with the J's is it won’t do a whole lot for the car until the header/exhaust is replaced and the car is remapped.

 

[logik]

No me and Stu dont have Kpro. We made around 186-189 WHP. Torque or between 143 and 148 lbs.

 

[D@nCeR]

well mines always been done in 5th..

got 229 bhp and 206l/bs torque

its in there now getting cams fitted

 

[logik]

Is that 229 WHP? Does that figure not seem low for all the work you have done if it is in fact BHP?

 

[LA-DC5 ITR]

148 torkeys and 197 WHP spike.