UKGPL Season 21 (2011) Grads (67) - Silverstone (GP 1952-73) - Jun 19

[Arf Arf Arf]

..how embarrassing....



Sorry....

[b_1_rd]

 

easily done lol

[vosblod]

..how embarrassing....



Sorry....

I only know that as I've done it a few times myself

[EvilClive]

In reply to Arf's query about engine blow ups.....

GPL of course does have a random failure element, but in my experience it still needs provoking before it will kick into action. I rarely experience an engine failure during a race in the Honda despite its reputation for being "fragile". Less than one engine per season fails on me in 67's ( Now I have said that I will of course expire in the next 5 races!!

I think that 90% of over revving ( the major cause of engine failure in GPL) happens on DOWNshifts and not on UPshifts. Usually when you are downshifting for a corner you are preoccupied with braking and turn in points and mirrors etc. and snapping down through the gears is almost done sub conciously.
Whereas, once you have got the car to the apex, and miraculously discovered that it is still under some directional input from yourself, you actually have the time to watch the red needle as you accelerate away and avoid those extra "killer" 500 revs.

The best way to check is to watch your own replay from "in car" and see what the rev counter is doing at the end of the straight as you change down through the gears. If you find that you are flicking the needle against the stop or that it spins round 3 times and flies off, then you have probably located the source of your problem  The remedy is to delay your downshifts, so maybe you drop from 5th to 4th at the point where you would normally be going 4th to 3rd? This will probably mean that your last shift into 2nd for a tight corner will be made right before the Apex of the corner, but with practice you should get the hang of it.
The other warning sign to watch is the OIL TEMP on the Pribluda display. For the Honda the killer temp is around 260 deg F. A few seconds at that temp and there will be a bang followed by an eerie silence from behind, other cars are slightly different ( not the bang bit, the 260 degree bit  ). If you notice the temp getting close to that danger level then you are overstressing the engine and need to change something. Either raise the gear ratios so that you peak safely below the red line or perhaps you are a gear too low in a fast bend and running on th rev limit where you could be a gear higher and still maintain your speed?

[Ronniepeterson]

Everything Evils says about engines is evil and correct. I blew mine twice in the race. I need to check the replay when I get a chance but I suspect the first was a my unnecessary downshift at turn 1 on the first lap - very harsh of GPL but its like that sometimes. The second no doubt was due to overheating/stressing the engine trying to get back into contention - cruel but fair of GPL. I do wonder about other factors like spending time off track and getting knocked about adding to the increased likelihood of engine failure. Unlike Evil I suffer from this quite a bit during the course of a season, just ask my Porsche International teamates. Sorry Juha and Axel I will try and look after the next one.

[ivandjj]

Very äppy that i finished a 50 mins race, first such case since 06 or thereabouts. Even more very appy that i managed to keep other cars in sight for most of the race. Some of them even got behind me while they were running, but i suspect the conspiracy coz everyone behind me always retires and i always finish last  :'(

Seriously, acceleration tracks like Silverstone aren't my strong point and i was surprised that Fulvio and Rick weren't getting away. When Fulvio went ahead and Rick and Clive fell behind, i lost the focus and of course spun. Didn't change the position, but it shows there is still some way to restoring confidence and arm muscles needed for this torture  

I'll be away for most of July, really sorry to miss races now that i got going a bit more seriously. But thats life, gotta sacrifice a bit of gpl for sun and the beach  

[blito]

i suspect the conspiracy coz everyone behind me always retires and i always finish last  :'(

Ive noticed that a few times.. even when running quite high in the order there will be a lot of retirements behind me but not many in front!

Have fun on your holiday m8

[BadBlood]

You are both too quick - I never see retirements behind - always in front and I STAY last even when I lap Hannah! Sigh.

[Arf Arf Arf]

I've just watched the whole race through, watching most drivers for a few laps (and my whole race). Its amazing how many different styles there are...

The best way to check is to watch your own replay from "in car" and see what the rev counter is doing at the end of the straight as you change down through the gears.

Happy to report that this can't be the cause - I couldn't have told you before watching this, but I'm pretty good at downshifts.

Upshifts might need some work - I could be smoother, compared to some of you, and the rev counter does occasionally bang against the red needle. However, this is true for everyone I watched!

The other warning sign to watch is the OIL TEMP on the Pribluda display. For the Honda the killer temp is around 260 deg F. A few seconds at that temp and there will be a bang followed by an eerie silence from behind, other cars are slightly different ( not the bang bit, the 260 degree bit  ). If you notice the temp getting close to that danger level then you are overstressing the engine and need to change something. Either raise the gear ratios so that you peak safely below the red line or perhaps you are a gear too low in a fast bend and running on th rev limit where you could be a gear higher and still maintain your speed?

I don't use Pribluda, as I don't like the idea of having all that info on screen, but I might install it temporarily for training purposes.

Gear selection is interesting though. Some drivers are VERY conservative in their timing of changes, which may be the result of many retirements, or they may have been nursing problems. This of course reflects on the lap time achieved.

I think the gears I use for corners are appropriate, but it appears that I change gear more often than any of you..

Woodcote.
Most: 3rd, up to 4th on s/f straight, 2nd for Copse.
Me: 4th, getting into 5th on s/f before slowing to 2nd for Copse

Maggotts: Most through in 4th, me 5th.

Chapel/Hanger Straight:
We all seem to take Chapel in 3rd, tho if I nail the line I'll go up to 4th as I enter it. I'm in 5th way before the big yellow sign on the left, but most of you seem to be in 4th for most of the straight.

Abbey/Farm Straight.
Everyone seems to take this in 3rd going then;
Most: up to 4th for Farm Straight, and down to 3rd for Woodcote.
I'm up to 5th before the bridge and only drop to 4th for Woodcote.

All this seem to make sense in terms of the rev counter reading, and what it would look like if e.g. I took Woodcote one gear lower. Does anything I've said sound like its contributing to the problem?

Oh, and is the Cooper unreliable - never heard it mentioned. I think I'll try another car for the next race anyway, but Cooper has been reliable in training sessions.

Cheers

Arf

[bernie]

Super Cooper is Mega reliable,  in my hands anyway 

Re the gears   

It would depend on what ratios you are using , IMO the Coop has lots of low end torque and responds well to short shifting.

With most cars I find it pays to use a higher gear , e.g. 3rd instead of 2nd  to exit slow corners as it stops the inside rear tyre from spooling up and losing drive .

Also try to feed the power in rather than stomp on the gas (easier said than done in the heat of battle )

If you ever watched The late great Jim Clark or Alain Prost you would see just how smooth you can be and still go very quickly

Other smoothies  Mario Andretti , Emmo , Niki Lauda and currently Jenson Button   

 

[BadBlood]

I think the gears I use for corners are appropriate, but it appears that I change gear more often than any of you..

Bet you don't

On the subject of corner exit - is it better to use a higher gear with lower revs or a lower gear with higher revs? Surely you would get better acceleration away with the lower gear?

I also seem to slow down a LOT compared to most of you. I assume that I am just not pushing the performance envelope. If I try to go faster though, I spin.

[Hristo Itchov]

Revs don't matter, Paul, what matters is torque and that differs from car to car. Ideally (I think I've told you before) I like to reach gear change revs just after I exit a corner. Of course it obviously also depends on how fast you're actually going through a corner.

@Arf Arf Arf

I don't use Pribluda, but there's this nice little patch which makes the info from the F10 camera available while you're in the cockpit as well. Useful to keep an eye on the engine temps, fuel pressure, speed and gears. Got to the following site, click Utilities, then Lee and Stefan, and you'll see it, it's called GPL Digital Display Modifier:

http://gplpp.com/

[BadBlood]

I thought these things had a torque sweet spot towards the top of the rev range or is it different gear by gear? When I use the Setup manager to set the gears to maintain 90% thrust as much as possible (from the graphs only) I frequently find that on track it is useless and I can't actually get the car up to those rev ranges.

I am fairly smooth though corners but I still drive like a road car where I am slow enough to drive around instead of sliding round. Until I can 'get' that I am going to continue to be slow although it is getting better. For instance, at Albi last year, I was lapping in the low 1:19's. I am now disappointed if I don't do a 1:17. 1:16's and even high 1:15's are definitely possible so there is progress but I seem to have gone backwards in the 67's whilst improving in the 65's.

Ah well. More practice I suppose.

[EvilClive]

Hristo is right about torque. You want the car to be delivering the maximum grunt that it can transmit to the tarmac without losing traction and therefore control. This requires a good "feel" for what is happening and is a skill that most of us are constantly trying to perfect. The problem is that setup changes and different tracks conspire to create a different "feel" each time you drive.

For some cars the "sweet spot" is NOT at the top of the rev range. The 65 Honda is a perfect example. The red line shows at about 13.5k on the tacho but running at anywhere near those revs will blow the engine and you will be slow because the power curve drops off dramatically at higher revs. Max torque is delivered around 12k and the car is fastest when kept in the 10.5k-12k range, considerably lower than the max indicated revs.
I find that the 66 BRM 2 litre on the other hand I can run at almost max revs for a whole race and really thrash it within millimetres of its life without any ill effects. But these things you only find out from experience.

One way to overcome the technical problem of traction and torque , is to "power slide" the car on opposite lock and actually use the resultant wheelspin like a virtual clutch, modulating the throttle to gain or lose grip.......Spectacular and a good crowd pleaser, but ultimately not the quickest way around the corner, plus of course it absolutely screws the rear tyres!! One or two drivers have been reported as using this technique when they are too lazy to concentrate on correct lines etc...

or

by arranging your gear ratios such that you can use maybe 3rd instead of 2nd and be just into the bottom end of the torque band as you exit the corner. This will allow you to be more brutal with the gas without breaking the traction of the rear tyres and give you nice big lazy gaps between gear changes. Once again, not the fastest way around a corner but sometimes a useful way of being consistantly quick and smooth for longer races.

or

you concentrate on getting your braking and turn in points for every corner absolutely spot on, along with your gear ratios so that you take each corner at the maximum velocity and on the edge of the adhesion envelope and lap at WR times.........simples

[ivandjj]

BB, you sound as if you're not comfortable enough with your setups. What values for brake bias, diffs, clutches are you using in 67s?