Trackday cooling
Discussion
A 15 minute session of hard driving at Goodwood saw my Griff maintaining 100C.
A full cool down lap in 5th at 60ish was enough to cool it right down after (although once I took it for a drive out on the roads since I found half a cool down lap was not enough.
(PS Im aware its also to cool the brakes).
I have never seen above 90C on the roads. I have a lower otter switch fitted (an 82 I think).
I have an open pit at Silverstone next and a touring hol across europe.
1. Is 100 degrees an OK temperature to maintain on the track?
2. Will a small plate make any difference (my current plate is huge and fills the whole hole).
3. Will adding the rad splitter make a big enough difference?
4. Will Water Wetter work well when wanging wound wacing circuits??
Thanks
(I told you Id be back for more question seven after I bought the Griff. I think I just found a suitable topic!).
A full cool down lap in 5th at 60ish was enough to cool it right down after (although once I took it for a drive out on the roads since I found half a cool down lap was not enough.
(PS Im aware its also to cool the brakes).
I have never seen above 90C on the roads. I have a lower otter switch fitted (an 82 I think).
I have an open pit at Silverstone next and a touring hol across europe.
1. Is 100 degrees an OK temperature to maintain on the track?
2. Will a small plate make any difference (my current plate is huge and fills the whole hole).
3. Will adding the rad splitter make a big enough difference?
4. Will Water Wetter work well when wanging wound wacing circuits??
Thanks
(I told you Id be back for more question seven after I bought the Griff. I think I just found a suitable topic!).
This is probably way off target….but. I was poking around under the bonnet a few weeks ago and noticed that there were some cracks in the alternator / water pump belt. As a precaution I fitted a new one and immediately noticed that the engine ran about 5 degrees cooler. I guess the old belt was not 100% effective at driving the water pump. Worth checking as it is dead easy to fit and not expensive.
Cooling system runs fine at all other times, it just gets hot on the track. Well, it still maintains the temperature, but just at 100C instead (at least thats what it looks like the guage says, hard to actually see it).
As far as I know all is in good order. Its serviced regularly (just had one about 1000miles ago which is about 3-4 weeks for me now the honeymoon period is over!), the belt is fine (but carry a spare anyway) and the collant and cooling system all appear ok.
I ways pop the bonnet and leave the fans on for a while when I enter the paddock too. But I dont have the front splitter/lip spoiler.
After the wet sessions (just the track was greasy) the car remained at 90 and below where I wasnt pushing it as hard.
It was only on the dry runs it got so high, but then I was giving it everything it asked for!
(What a truly fantastic fun car to drive. I still cant believe the levels of grip compared to what I was expecting).
I think I'll go for the smaller front plate beacuse
A: it might help airflow over the engien and prevent heat soak for the Euro holiday.
B: It looks better!
I have hear good things about the spoiler so I'll make one of them too. (It supposed to stop the bonnet flap at speed and improve stability)
And the fan override.
I should have done this ages ago really, just never got round to it. I see what I can muster up at the weekend.
Thanks for all the suggestions. I'll keep you updated (but you already knew that!).
As far as I know all is in good order. Its serviced regularly (just had one about 1000miles ago which is about 3-4 weeks for me now the honeymoon period is over!), the belt is fine (but carry a spare anyway) and the collant and cooling system all appear ok.
I ways pop the bonnet and leave the fans on for a while when I enter the paddock too. But I dont have the front splitter/lip spoiler.
After the wet sessions (just the track was greasy) the car remained at 90 and below where I wasnt pushing it as hard.
It was only on the dry runs it got so high, but then I was giving it everything it asked for!
(What a truly fantastic fun car to drive. I still cant believe the levels of grip compared to what I was expecting).
I think I'll go for the smaller front plate beacuse
A: it might help airflow over the engien and prevent heat soak for the Euro holiday.
B: It looks better!
I have hear good things about the spoiler so I'll make one of them too. (It supposed to stop the bonnet flap at speed and improve stability)
And the fan override.
I should have done this ages ago really, just never got round to it. I see what I can muster up at the weekend.
Thanks for all the suggestions. I'll keep you updated (but you already knew that!).
yes to all points...
down side you may not have thought of...
if you're running 100 on the guage, the block will be a touch higher (5 degrees), not tooo much to worry about, unless your belting round the track!!
AND THE ECU WILL HIT OVERTEMP MAP TO PROTECT THE ENGINE!
-30 ODD BHP!!!
now that IS serious!!!
do the plate, spoiler,fan over-ride straight away.
should be fine for UK tracks. run the car to temp (in the pits as norm) then switch on the fans when exiting.
no probs
have fun
down side you may not have thought of...
if you're running 100 on the guage, the block will be a touch higher (5 degrees), not tooo much to worry about, unless your belting round the track!!
AND THE ECU WILL HIT OVERTEMP MAP TO PROTECT THE ENGINE!
-30 ODD BHP!!!
now that IS serious!!!
do the plate, spoiler,fan over-ride straight away.
should be fine for UK tracks. run the car to temp (in the pits as norm) then switch on the fans when exiting.
no probs
have fun
I found out today exactly how much difference having the splitter in place makes, because I snapped mine off on a 
hidden kerb when I parked the Griff at work this morning. I wasn't on a track but my route is M25 M3 so fast enough. Anyway, temp on way to work was a steady 81 degrees as always on a warm day, temp on return 89 degrees all the way (never seen before in this Griff) so I reckon the splitter takes 8 degrees off the temp.
I bet it doesn't go back to 81 when I refit it though!
hidden kerb when I parked the Griff at work this morning. I wasn't on a track but my route is M25 M3 so fast enough. Anyway, temp on way to work was a steady 81 degrees as always on a warm day, temp on return 89 degrees all the way (never seen before in this Griff) so I reckon the splitter takes 8 degrees off the temp. I bet it doesn't go back to 81 when I refit it though!
Perhaps you should change your name to "roadsweeper"!
The optimum efficeint running temp is 90 so there isnt any point in trying to run cooler than that.
BUT....before you can jump down my throat....its also not so good to be going over 90.
My Golf TDi stays at bang on 90 constantly (once warmed up) regardles of how its driven. I have a feeling this is more to do with instrumantation damping than super effective temperature control.
Hopefully on Sunday I'll be able to crawl and a Griff and nick a splitter
Seriously though, I think I'll have to set about making one. I'll take a look a yours k77 and go from there. Im thinking about using a hard rubber, such as that that hangs of the front of 90's Fords.
The optimum efficeint running temp is 90 so there isnt any point in trying to run cooler than that.
BUT....before you can jump down my throat....its also not so good to be going over 90.
My Golf TDi stays at bang on 90 constantly (once warmed up) regardles of how its driven. I have a feeling this is more to do with instrumantation damping than super effective temperature control.
Hopefully on Sunday I'll be able to crawl and a Griff and nick a splitter
Seriously though, I think I'll have to set about making one. I'll take a look a yours k77 and go from there. Im thinking about using a hard rubber, such as that that hangs of the front of 90's Fords.
It seems to be common practice for production cars to heavily bias the temperature gauge towards the normal running temperature, so it seems to come up to temperature very quickly and never seems to overheat.
The optimum efficiency thing is an interesting one. I heared about some tests recently where the same engine was run on a test bed at various temperatures +/- 30 C from the normal running temperature. The efficiency did not change measurably. Intuitively I would have expected more heat loss to water when the engine is running colder and hence less efficiency, but it seems when the combustion chamber is full of gas at 1000 degrees it doesn't really matter whether the cylinder walls are at 70 degree or 100 degrees.
>> Edited by greenv8s on Friday 30th July 12:36
The optimum efficiency thing is an interesting one. I heared about some tests recently where the same engine was run on a test bed at various temperatures +/- 30 C from the normal running temperature. The efficiency did not change measurably. Intuitively I would have expected more heat loss to water when the engine is running colder and hence less efficiency, but it seems when the combustion chamber is full of gas at 1000 degrees it doesn't really matter whether the cylinder walls are at 70 degree or 100 degrees.
>> Edited by greenv8s on Friday 30th July 12:36
We have just come back from our holiday in the Italian mountains. Last year we had some pinking and heat problems. This year everything was perfect, the changes I made to the car were:
Frontspoiler fitted, increase in air going throught the radiator, this lowered the temps considerably and optimized the cooling.
Water wetter in the coolingsystem, this stopped the pinking.
Bleeding of the radiator, I was amazed of the ammound of trapped air.
I can't comment on trackdays but you can imagine that racing up a 2500 meter mountain pass has about the same if not bigger effect on the temps. The engine has to work VERY hard to stay ahead of the motorcycles that followed us, plus there's less air to work with.
Air temperature down below was about 30, on top about 20 degrees. The car never came close to the red on the gauge, I guess about 95 degrees maximum by the time we reached the top. Oil temp about 120 degrees maximum, thank's to the oilcooler this was down to 100 degrees in no-time.
Fred
PS I won't mention the brakes, that's an entirely different story.....
Frontspoiler fitted, increase in air going throught the radiator, this lowered the temps considerably and optimized the cooling.
Water wetter in the coolingsystem, this stopped the pinking.
Bleeding of the radiator, I was amazed of the ammound of trapped air.
I can't comment on trackdays but you can imagine that racing up a 2500 meter mountain pass has about the same if not bigger effect on the temps. The engine has to work VERY hard to stay ahead of the motorcycles that followed us, plus there's less air to work with.
Air temperature down below was about 30, on top about 20 degrees. The car never came close to the red on the gauge, I guess about 95 degrees maximum by the time we reached the top. Oil temp about 120 degrees maximum, thank's to the oilcooler this was down to 100 degrees in no-time.
Fred
PS I won't mention the brakes, that's an entirely different story.....
DustyC - This may not be relevant to a Griffith but I replaced the double sided sticky stuff on the Cerb with heavy duty sticky velcro stuff. Pull up at the track day, tear the number plate off. End of day stick it back on again. No problem! Makes a lot of difference to cooling.
Washy
Washy
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