CambioCorsa change down from 4th to 3rd...

[BenjaminBraddock]

I took the car to a driving day on Friday and found at one section of the track when I tried to change down from 4th to 3rd, the car over ruled me and stayed in 4th. It only happened at the same one section of the track which was the fastest section where the revs were higher.

The same 4th-down-to-3rd change was fine at other points on the track and driving home.

I concluded that the likely reason is the CambioCorsa box is set up to prevent changing down if the revs/speed is deemed too high - does anybody know if this is the case?

Thanks, Simon

 

[Contigo]

Yes because it rev matches on down change then if you try to select a lower gear and the revs are too high then it won't select that gear for you.

This is a case which us bods in the IT industry refer to as P-I-C-N-I-C syndrome...... Problem In Chair Not In Computer....

 

[CatmanV2]

The previous member has the right of it

C

 

[MAF260]

What Phil said. The electronics must have worked out there either weren't quite enough revs left to change down, or you'd be bouncing off the limiter. I was given a great tip at Brunty a few years ago by Grinzzz - to drive using the torque (out of the chicane in this instance) rather than revving the car to the red line. This worked/works a treat and I now carry more speed on exit and a higher top speed on the final long straight. Still can't catch or beat those GTRs though...

 

[BenjaminBraddock]

Thanks guys yes makes sense - I only had this happen later on when I had more confidence and was used to the track so driving more aggressively

 

[MAF260]

How did you get on with the noise test, Simon?

 

[BenjaminBraddock]

It passed the noise test easily Mark - I swapped the Larini rears back to the factory ones, still with the H-pipe on though, the difference is massive, not sure you would approve though Mark.

The Larini rears make about 10dB difference. Hearing some of the other cars though made me wonder if it would have squeezed through.

Although it now doesn't rattle the windows of passing houses, I quite like the change - I can hear the glorious V8 engine now. I'm sure I'll revert to the Larinis again though, they do have presence!

 

[MAF260]

It passed the noise test easily Mark - I swapped the Larini rears back to the factory ones, still with the H-pipe on though, the difference is massive, not sure you would approve though Mark.

The Larini rears make about 10dB difference. Hearing some of the other cars though made me wonder if it would have squeezed through.

Although it now doesn't rattle the windows of passing houses, I quite like the change - I can hear the glorious V8 engine now. I'm sure I'll revert to the Larinis again though, they do have presence!

That was worth the effort, then. Which circuit was it? Aside from Brunty my car has never been on a track. I've long suspected it would fail any test by a considerable margin, so have never bothered. There are few tracks I think the car is suited to as it's quite heavy and I don't want to replace tyres and brakes each time. Maybe my driving is just cr@p! Cue comments from the usual suspects....

 

[Contigo]

Try Llandow Mark.

 

[BenjaminBraddock]

That was worth the effort, then. Which circuit was it? Aside from Brunty my car has never been on a track. I've long suspected it would fail any test by a considerable margin, so have never bothered. There are few tracks I think the car is suited to as it's quite heavy and I don't want to replace tyres and brakes each time. Maybe my driving is just cr@p! Cue comments from the usual suspects....

Was at Brands Hatch on the Indy circuit which is a brilliant track to drive - highly recommend it if you get a chance. Although as you say you probably wouldn't make it passed the noise test with your current set up, but only a small task to stick the factory rears back on.

I'm going to leave the factory rears on for the time being - a change isn't a bad thing.

If I get a chance I'll attach a clip of the Larini H-pipe and rears I took before removal which sounded like thunder....

 

[Steve GS]

I always thought it only adopted a safe gear when not in sport mode. I'm sure I read that. I Maybe wrong

 

[CatmanV2]

I always thought it only adopted a safe gear when not in sport mode. I'm sure I read that. I Maybe wrong

It won't red line itself, sport or not.

C

 

[Steve GS]

It won't red line itself, sport or not.

C

My gs will in sport. I don't know how different the set ups are.

 

[Contigo]

It won't down change into redline revs. It will hold the gear at the limiter until you upchange when in Manual Sport mode.

 

[mjheathcote]

It won't down change into redline revs. It will hold the gear at the limiter until you upchange when in Manual Sport mode.

Correct.
It's all rather clever really, or you could say a simple look up table in code!

 

[Contigo]

I wanted to do some research into the downchange rev limits and found this in the academy document.

When downshifts are performed at an engine speed superior to 5000 RPM, doubleclutching is performed automatically to raise the engine speed before engaging a lower gear.


Note: in Manual-Sport mode, no automatic upshifts are performed when the engine reaches the maximum RPM and the accelerator pedal is depressed. The engine will remain at speed limiter revs if no manual upshifts are performed. (This one we knew!)