UKGTL Season 17 1967 Can-Am - Laguna Seca - Jul 10

[Bob M.]

Clive:
The sound pattern of the Chappy is because of the torgue converter used in the drive train.  They probably used around a 3K RPM stall speed.  This means it really didn't hook up and transfere much power until this RPM.  So the sound seems almost constant regardless of the car speed.  My son just sold his 70 Pontiac GTO he restored and built up with a much modified drive train (461 cubic inch with 3 speed auto) and it sounded much the same with a 2800 RPM stall speed converter. Ease in to the floor and  just a steady howl, shift, howl some more, shift and soon you were thinking, Ok son  I'm impressed it goes 140 MPH, let's slow her down now!!!!

Bob M.

[Wiltshire Tony]

My son just sold his 70 Pontiac GTO he restored

No pictures? (Don't use Photo*ucket)

[EvilClive]

 Yep Bob, having been around in the 60's I knew about Phil Hall and the "special" transmissions used for the Chapps, but that does not help my..... audio input vs speed perception... brain cell operation, when we race in GTL 

It was easier when I was slot racing in the 60's and some of us rigged up pendulum systems to operate the high rear wing and gain downforce ( at least we hoped that it did, but I am still not convinced that it made any noticeable difference ) at least the little 12v motors could be heard spinning up to full revs!! lol

By the time I gave up last night I was beginning to get a feel for the odd pick up out of the corners, but it still doesn't feel entirely natural to an oldie like me. I still expect the revs to build in proportion to the speed.

[phspok]

I did some testing with the Chappies, and thought the revs a bit odd, but I don't remember it
being particularly off putting, I though they were just low revving. But then I am often accused
of being a bit deaf 

[Ziu Bacubacu]

If one can get sub 1:04 with Chaparral, i think that the engine sound not is a big problem

[Jeep]

Hi Bill,
 You have changed the tyres from the default set up I presume? The endurance tyres have a lot less grip.

A rough guide to how I've started to set these up is to move the brake balance rearwards and reduce the brake pressure down to about 92%, Then I just mess around with the balance until progressive application of the brakes locks all wheels together. Then try some serious downshifting (Approaching a corner for example) and I add coast side diff until I can control the rears. I usually reduce the power side diff down a click or 2 as well. I also sometimes lower all the spring rates and usually reduce the tyre pressures a few clicks. Finally raising the front ride height and/or lowering the rear also helps as does reducing the rear roll bar (Or increasing the front). Finally if all else fails I've even resorted to putting the endurance tyres back on the front.

TTFN
John.

[phspok]

Try the 2E BIll if you are not already, that one should be an easier drive.

If one can get sub 1:04 with Chaparral, i think that the engine sound not is a big problem

 

[SpecialKS]

Give this one a miss. Best so far 1:18  and that was the only lap I was able to hold the beast on the tarmac.

Have fun guys.

[Wiltshire Tony]

Results and replay now posted

[EvilClive]

Hi Bill,
 You have changed the tyres from the default set up I presume? The endurance tyres have a lot less grip.

A rough guide to how I've started to set these up is to move the brake balance rearwards and reduce the brake pressure down to about 92%, Then I just mess around with the balance until progressive application of the brakes locks all wheels together. Then try some serious downshifting (Approaching a corner for example) and I add coast side diff until I can control the rears. I usually reduce the power side diff down a click or 2 as well. I also sometimes lower all the spring rates and usually reduce the tyre pressures a few clicks. Finally raising the front ride height and/or lowering the rear also helps as does reducing the rear roll bar (Or increasing the front). Finally if all else fails I've even resorted to putting the endurance tyres back on the front.

TTFN

John.

lol John. I have just read your advice after FINISHING the race!! From what I can recall I think that I did exactly the opposite!!! I know that I dropped the coast side to 0 and upped the power side to around 75. dropped brake efficiency to about 88 and set the balance at around 48/52. I did have to play with tyre pressures and cambers.
I did manage to hussle the thing around but the setup was far from ideal, just one percent too much gas out of a corner and the oversteer was suicidal and there was no recovering even with armfuls of opp lock........something that bit me in the a** a couple of times during the race.

the race was good fun but kinda ruined by a blank screen for about 5 secs at the start of lap 2!!  Just when the tyres were getting up to temp and I was still in touch with Erling and Ziu. After that I was playing catch up and Matt refused to crack after many laps of pressure. But it was great fun looking for the chance to pass, with 2 very different cars. Eventually the oversteer caught me out at T4 and sent me cross country, bending something important in the suspension/steering department.
The car was not quite the same afterwards and getting that dammed thing moving without stalling proved impossible and it gave Matt a 20 second buffer that I just could not close down again with a dodgy car.

But at least I finished a Can Am race and I just happened to notice that I set the FL  .......in a Chappy!!!!!!! lmao  Maybe there is hope for me in these cars???

[Ziu Bacubacu]

Race report:


It s easier solve a Chinese puzzle than overtake on this track.

Grats Erling and Matt. Don't worry John here can happen.

[Jeep]

Ah Clive, GTL works the opposite from GPL. GTL is locking %age whereas GPL is ramp %age. (No, it means nothing to me either, all I know is that's how it works). 

Well a race of mixed emotions for me, Qualified in 4th a few tenths short of my PB but it would not have pushed me any further up the grid as Clive was over half a second ahead of me.

Flag dropped and I struggled to keep the Chappy in a straight line but managed to draw level with Clive before he shut the door in my face and I also got a nudge from Matt but managed to hang onto 4th place. A few laps later Clive went off track (Due to his blank screen) and I inherited 3rd. Managed to extend away from Matt and Erling and Ziu likewise extended away from me. I think Ziu made a few mistakes during the race as occasionally I would get back within  around 4 seconds only for him to begin to pull away again.

Than with around 4 laps to go I could see I was actually gaining on him by nearly a second a lap. Problem?? Managed to get on his tail a few times but couldn't find any way through. Finally onto the last lap and I'm right with him with Matt around 20s back and disaster. I knew I had to get a good exit out of the left hander and onto the up hill section to the Corkscrew as that was my last chance where only having 2 gears to play with might be to my advantage, So up his A$$ into the turn but he was a lot slower than I had expected and I rear ended him waited for him to come past but I think he had a flat tyre so it was slow progress following him (But obviously no way I was going to steal his place after causing the accident). All this time Matt was closing at an alarming rate finally out of the last turn I waited to let Ziu past and Matt said "Thanks a lot" and followed him through so dropping me down to 4th.

So disappointed to have lost the podium spot but very glad Ziu didn't actually lose his 2nd place.

Thanks guys.

TTFN
John.

[Erling G-P]

Thoroughly enjoyed that one     Normally not crazy about Laguna Seca, but this version in these cars was an absolute hoot.

Picking a car wasn't easy though.  Had just about settled on the Lola, when Ziu's musings about the M1b persuaded me I should give it another shot.  Tried and tried and tried to tame the Ford powered one, to no avail.  Nothing I did to the rear suspension seemed to have any effect - it remained suicidally oversteery no matter what.  Best laps were in the 1:05s.  Little more luck with the Olds powered one, which I could balance better.  Still far from Ziu's Turkish things though, with a best lap of 1:04.2.

At that time, I had done a 1:04.8 in the Lola 350, so not much between them.  To get a more realistic picture of which one would be fastest in a race, I decided to time a 10-lap stint in each. Needed a few familiarization laps in the Lola, after all the M1b driving.  During those, I quickly matched and then pipped my best time in the M1b.  A couple minor tweaks to the setup shaved off further time, culminating in a 1:03.5 lap.  That decided my car choice - why waste a McLaren on something I could do quicker, and with much more confidence in a Lola ?

Briefly also tested the two bigger engined Lolas, but prefer the 350.

Once again I got a dream start in the Lola, shooting ahead of Ziu and grabbing the lead.  Retaining it would be an entirely different matter though.  What followed was 31 laps of 'drive it like you stole it, but DON'T stuff it!!'.   Staying ahead of Ziu was not easy for an Earthling like me.  He got very close a few times, under the bridge, but fortunately the mirror is useless in the Lola, so didn't know how close he was, as that would have made me nervous    Apologies for shutting the door hard Ziu; simple explanation is I had no idea where you were exactly - your engine noise didn't betray your position, as it was just a constant rumble in the background.

Ziu went off early on, handing me a 6-sec gap. Naturally wanted to exploit it to the fullest, but instead made small mistakes that quickly saw it dwindle again.  Stayed around 3 secs for a long time, when I drove to my max.  With 5 laps to go, it suddenly jumped to 14 secs, as Ziu obviously had gone off again.  An absolute gift, as I could ease off and coast home the last 5 laps - bar computer or internet issues (or supremely stupid mistakes from me), the win would be mine.

Fortunately held to the end and a most unexpected result.  Grats to Ziu & Matt for filling the podium; commiserations to John and anyone else with troubles.  Thanks to those I lapped for helping me past; hope it didn't upset your own battles too much.

Cheers,
Erling

[Ziu Bacubacu]

Yesterday three drivers under 1:04, qualy and race with  two LOLA and one Chaparral. My remains a staple, with McLaren would have been possible go under 1:03 with M6A also. If one car is fast  it s fast on each tracks and mostly i did two race with McLaren and Lola, McLaren not serius problems with tires with LOLA yes (at least with 372) yesterday at 15 laps to go started problems at 7 laps to go my tires were red zone on XD and the rear was slipping too much   

[Erling G-P]

Tyre wear in the 350 was manageable; rears had wear rates of 13-14 at the end of the race.  Biggest problem was that the rears were wearing roughly twice as fast as the fronts, altering the balance as the race progressed.  Had to compensate for that.

Cheers,
Erling