In response my recent post about the pros and cons of a NA Exige vs. an ‘S’, there were a couple of comments about the ‘overheating’ problems with the ‘S’. I can’t track down any posts about this.
Is this a real issue for an ‘S’ used mainly on the road? I’ve just ordered one and I 'd like some feedback before collection next week.
Cheers
One heat issue is to do with the intercooler suffering from heat soak. Because it sits right above the engine it gets affected by the hot air rising from the engine. The guys at Bemani in Switzerland did some runs on a dyno and found that the between 20-10hp was lost due to heat effecting the intercooler efficiency. A charge cooler is more effective than an intercooler that�s why KomoTec have developed the Water Jacket and the GT3 racecars have chargecooling this year.
The thing to avoid is running the engine hard and then allowing it to sit (either in the pit lane or in traffic). On track I would suggest two cool down laps to reduce
BTHW This would prob be better in the S2 section and if you look back in there there is info.
Cheers Jamie
Thanks Jamie, I’ll look at the S2 posts again.
Just to clarify,
Jamie is correct. The issue is the efficiency of the intercooler in hot climates and the loss of efficiency when heat soak from the engine raises the temp of the cooler itself.
The S never runs too hot from an engine water temp point of view. I have run mine in 30 min sessions, flat out on the grand prix circuit at hockenheim in almost 40 degree heat and have never had the tempo go above its normal operating temp.
Thanks for putting my mind at rest. Really looking forward to collecting the car this Friday, subject to snow drifts - bugger!
the temps on your readouts will not go up just the performance will go down
you will notice more when summer is here.
Bad design.
the temps on your readouts will not go up just the performance will go down
you will notice more when summer is here.
Bad design.
…as in all piston engines.
One heat issue is to do with the intercooler suffering from heat soak. Because it sits right above the engine it gets affected by the hot air rising from the engine. The guys at Bemani in Switzerland did some runs on a dyno and found that the between 20-10hp was lost due to heat effecting the intercooler efficiency. A charge cooler is more effective than an intercooler that�s why KomoTec have developed the Water Jacket and the GT3 racecars have chargecooling this year.
The thing to avoid is running the engine hard and then allowing it to sit (either in the pit lane or in traffic). On track I would suggest two cool down laps to reduceBTHW This would prob be better in the S2 section and if you look back in there there is info.
Cheers Jamie
Clearly cooler is better but it’s difficult to believe that a dyno run will replicate normal running/airflow conditions sufficiently well to produce anything like accurate figures?
I have not had any cooling issues with my ‘S’ on several track days and on the road. With regard to the intercooler efficiency, IMO the problem is the location of the air intake on the roof - it would appear to be in a low pressure area. However the car still goes very well in spite of that and we all may be wrong as I felt the intercooler immediately after a fast and hard track session recently and it was warm but not all that hot. It will get heat soaked when stationary after a run but should cool off quickly when the car is moving again if it is working properly. Finally, I would agree that dyno runs don’t mean much re the efficiency of the standard intercooler unless they are run in a wind tunnel.
Chris - welcome - who’s building your GT40 replica?
Hi Steve
The GT40 is being built from an Australian kit called Roaring Forties. Unfortunately, they decided to move production to South Africa because it was cheaper, but it turned out to be a disaster. I have got one of the only 2 kits to come out of SA before the company went bust.The kit wasn,t complete when I got it despite my having paid the full price (big mistake) so I have lost a few thousand but not nearly as much as some people who paid out big money and received nothing. Also there was a delay of over a year before the partial kit was delivered.
The good news is that I have been pressing on with the build but am about to hand the project over for someone else to complete for me as I will shortly be taking delivery of a quickbuild aircraft kit (my other interest apart from cars - I have already built 2 aircraft over the years).
The GT40 is well specced, with AP brakes - 6 pot on the front and 4 pot on the back plus AP master cylinders. Also most of the suspension is rose jointed, with layout as per the original. I have had a small block Ford 302 engine made up which is stroked to 5 1/2 litres. I have seen it running on the dyno giving 442 bhp at 6,000 rpm with huge torque from about 2,500 rpm. The complete car is supposed to weigh 1000 kgs (although I will believe that when I see it), so should be exciting, especially as it will be completely unsorted - unlike the Lotus which handles very well out of the box. Anyway, you will hopefully see it at track days next year. I just wonder if I am man enough to handle it!
Chris