36 replies to this topic

[lotusv6seven]

Hi guys

Finally, we could fit 17th sprocket, and 27 step chain by loosing diff case before. By the way, anyone knows max speed with 10´wheels at 11.000rpm?

Now, a Tranex LSD has been fitted in too.

Edited by lotusv6seven, 15 October 2009 - 03:45 PM.

[Monte Busa]

Nice catch there right at the end of the video - that's my worst fear with track daying a Mini - the dreaded mid corner rollover!

Hi guys

Finally, we could fit 17th sprocket, and 27 step chain by loosing diff case before. By the way, anyone knows max speed with 10´wheels at 11.000rpm?

Now, a Tranex LSD has been fitted in too.

Edited by Monte Busa, 22 October 2009 - 02:18 AM.

[Monte Busa]

I'm running 10" wheels too and the same gearing, and I get almost exactly 56MPH at 6000RPM in 6th gear.

That would put max speed at 11000RPM in 6th at 11 / 6 * 56 = 102.7MPH - sounds about right

Hi guys

Finally, we could fit 17th sprocket, and 27 step chain by loosing diff case before. By the way, anyone knows max speed with 10´wheels at 11.000rpm?

Now, a Tranex LSD has been fitted in too.

Edited by Monte Busa, 22 October 2009 - 02:19 AM.

[lotusv6seven]

I expected that. It´s fair enough for a small and twisting track as Guadix.
Many thanks. I guess 18t sprocket rise to 110-112 MPH...

[Monte Busa]

yup, 18T would bring max speed to 11000 / 6000 * 60 = 110MPH. The 17t works best for my local track too, as the max speed is about 96MPH - so the engine is very close to it's power peak where it's needed most. I use 3rd, 4th, 5th, and 6th gear on that track (Waterford Hills Raceway, in Clarkston MI, USA - 4th and 5th mostly, but 3rd and 6th where I need it. Here's a video (with 17t):

http://www.youtube.c...u/0/sYMhX02szII

Not the most manic lap I've ever done there (I've gone about 4 secs quicker by now), but gives you asense of the gearing.

I expected that. It´s fair enough for a small and twisting track as Guadix.
Many thanks. I guess 18t sprocket rise to 110-112 MPH...

[cad13]

"quote"I use 3rd, 4th, 5th, and 6th gear on that track (Waterford Hills Raceway, in Clarkston MI, USA

Do you ever go up to the Canadian tracks? I spent some time working at Mosport and might be able to get us some track time next summer if you are interested. We would run with the BMW club. Tremblant Is also a possibility. It would be nice to have a reference once I'm done my build.

[Monte Busa]

I haven't made it to any of t Canadian tracks yet - but definitely will once my Z-Cars Monte is done...I think Mosport may be a bit too high speed of a track for the Pro-mo with the 103 to 110MPH top speed...

"quote"I use 3rd, 4th, 5th, and 6th gear on that track (Waterford Hills Raceway, in Clarkston MI, USA

Do you ever go up to the Canadian tracks? I spent some time working at Mosport and might be able to get us some track time next summer if you are interested. We would run with the BMW club. Tremblant Is also a possibility. It would be nice to have a reference once I'm done my build.

[lotusv6seven]

[quote name='Monte Busa' post='1621238' date='Oct 22 2009, 04:30 PM']yup, 18T would bring max speed to 11000 / 6000 * 60 = 110MPH. The 17t works best for my local track too, as the max speed is about 96MPH - so the engine is very close to it's power peak where it's needed most. I use 3rd, 4th, 5th, and 6th gear on that track (Waterford Hills Raceway, in Clarkston MI, USA - 4th and 5th mostly, but 3rd and 6th where I need it. Here's a video (with 17t):

http://www.youtube.c...u/0/sYMhX02szII

Not the most manic lap I've ever done there (I've gone about 4 secs quicker by now), but gives you asense of the gearing.




Hey Monte Busa, good video.
Apparently, car is runing smoothly (just apparently) but it looks very quick and gearing works!. What about your setup? I don´t get a good setup so car is brisk and jumping all cornering. I´ve tried with tyres pressures but it doesn´t work as I´d liked it.

I´ve also realised you have not problems with gear level, short way, very accuracy. Are you using promo wire? Mine doesn´t work as properly as I need!
Finally, excuse me all asking together, what kind of tail exhaust pipe are you using? Motorbike? Mine has a mini´s but I´ve heared bike can could give me 5-8 HBP more...

Edited by lotusv6seven, 24 October 2009 - 07:41 PM.

[Monte Busa]

The car does run very smoothly and the shifter works well. I'm using the cable (very stiff and strong one) as supplied by Pro-motive. the car shifts a bit better I've found by giving just a "little nudge" of clutch on upshifts, but I have had no issues - the only thing I watch is to make sure the brake lever pivot does not have any drag in it and it's been fine.

As far as my setup, during my first track outing I had a bit of the "bouncing" on the rear as your car seems to do from time to time per your videos - I cured that on my car by adding the rear anti roll bar and making absolutely sure I had 0deg toe in / out at the rear in addition to increasing the damping level on the rear by shock adjustment to close to the maximum value. I may have to run a bit higher pressure on the rear tires though now with the anti-roll bar as the weight transfer makes the tire wall deform quite a bit (I was running 16PSI warm on Yokohama A032s on the rear, with 22PSI warm on the fronts).

If I were you, and since your car is a dedicated track car (?), and if you're already running a rear anti-roll bar, I would try a very small touch of rear toe out - it will make the rear of the car turn in nicely as long as it's not overdone and it affects high speed stability. Also, make sure you're not running more than 0.5deg to 0.8deg rear negative camber - too much negative rear camber will make the tires bite too hard and not want to slide in the corners.

Hey Monte Busa, good video.
Apparently, car is runing smoothly (just apparently) but it looks very quick and gearing works!. What about your setup? I don´t get a good setup so car is brisk and jumping all cornering. I´ve tried with tyres pressures but it doesn´t work as I´d liked it.

I´ve also realised you have not problems with gear level, short way, very accuracy. Are you using promo wire? Mine doesn´t work as properly as I need!
Finally, excuse me all asking together, what kind of tail exhaust pipe are you using? Motorbike? Mine has a mini´s but I´ve heared bike can could give me 5-8 HBP more...

Edited by Monte Busa, 25 October 2009 - 04:21 PM.

[lotusv6seven]

Thank you for tips!
New setup for next trackday and I´ll tell you how it works.
Car uses dunlop slick tyres. I used to drive with Miglia´s recomendations, 30 psi front, 28 psi rear, not warm.
I´m not quite sure 16 psi warm. It looks not enough pressure. Anyway I´ll try if setup doesn´t work.

[Monte Busa]

The tire pressures were fixed by measuring a temp profile across the treads after a 20min track session - they are almost perfect as far as temperature distribution at 22PSI front / 16PSI rear (I checked my notes and my fastest run was at 18PSI rear), but the rear side wall deformation is a bit much on the rear as a I mentioned, so I'm going to play with that next time out. I dont' know how the radial AO32s would compare to your bias slicks...

Thank you for tips!
New setup for next trackday and I´ll tell you how it works.
Car uses dunlop slick tyres. I used to drive with Miglia´s recomendations, 30 psi front, 28 psi rear, not warm.
I´m not quite sure 16 psi warm. It looks not enough pressure. Anyway I´ll try if setup doesn´t work.

Edited by Monte Busa, 27 October 2009 - 12:37 AM.

[Monte Busa]

Hi guys - have you had any isses with your jack shaft / diff box input shaft? The splines on mine are almost 30% worn through with only 600 miles on the clock....hmmmm. Checking with the pro-mo boys about it....

[lotusv6seven]

Hi guys - have you had any isses with your jack shaft / diff box input shaft? The splines on mine are almost 30% worn through with only 600 miles on the clock....hmmmm. Checking with the pro-mo boys about it....

Hi Montebusa

Mine fits a TraneX LSD with Hardy spicer output flange 10 spline and competition shafts. I think if you are using 24 spline it could be quite usual. In fact, we changed to 10 spline thinking about wearing and 1000 trackday miles with no wearing prove it (at least in this stuff).

Edited by lotusv6seven, 10 May 2010 - 08:58 AM.

[roofless]

Hi guys - have you had any isses with your jack shaft / diff box input shaft? The splines on mine are almost 30% worn through with only 600 miles on the clock....hmmmm. Checking with the pro-mo boys about it....

mines fine, but not getting the punishment it really deserves - I recently had a rebuild on my diff though due to a failed bearing

[duds100]

Guys,

Reading this thread with great interest! My pro-motive mini is very near completion. I am running a 5PW, Tran-x LSD, 3.4 cwp, on 10" ao32r tyres.

Just to check I've got this right. If you guys are also on a 3.4 can you confirm.....

18 front/18 rear = ~110mph @ redline in 6th.
17 front/18 rear = ~100mph @ redline in 6th

What about 18 front / 17 rear? Would this not achieve longer gearing ~120mph?

Dudley