Ultima Broken Down at Le Mans (overheating)
Discussion
Hi,
I have a serious overheating problem with my GTR. It has a 535BHP American Speed Engine I have upgraded the fans to Pacet pro's at 2100 CFM but still overheating.
The main water pump and Air con belt had gone. Estimating that the number of times it had reached critical temperature (3) that day had stressed the belt and it finally let go.
Guy stopped at the breakdown site (2.5 miles from Le Mans) and stated that he had a new rad core and fans designed for his GTR that solved the issue. Can not remeber his name, too many beers since then.
Does anyone know of an aftermarket rad core and fans? does anyone have one? Has anyone re-designed a rad core?
Please help!!!!????
Your overheatingly,
Scuff (Le Mans Nick Name)
I have a serious overheating problem with my GTR. It has a 535BHP American Speed Engine I have upgraded the fans to Pacet pro's at 2100 CFM but still overheating.
The main water pump and Air con belt had gone. Estimating that the number of times it had reached critical temperature (3) that day had stressed the belt and it finally let go.
Guy stopped at the breakdown site (2.5 miles from Le Mans) and stated that he had a new rad core and fans designed for his GTR that solved the issue. Can not remeber his name, too many beers since then.
Does anyone know of an aftermarket rad core and fans? does anyone have one? Has anyone re-designed a rad core?
Please help!!!!????
Your overheatingly,
Scuff (Le Mans Nick Name)
See layada's post on this thread about a replacement rad:
www.pistonheads.com/gassing/topic.asp?p=1&f=20&t=192350&h=0
However, it may not be the problem.
www.pistonheads.com/gassing/topic.asp?p=1&f=20&t=192350&h=0
However, it may not be the problem.
Scuff said:
Guy stopped at the breakdown site (2.5 miles from Le Mans) and stated that he had a new rad core and fans designed for his GTR that solved the issue. Can not remeber his name, too many beers since then.
He said he was currently building a black GTR, and I think his nickname on PH started with an A.
James, It was me. I hope this helps…
I got totally fed up with the overheating and all the excuses "the car is not set up properly" "I have no problems" "the rad is big enough". Things like tweaking the idle mixture, getting it as low as possible, ceramic coated exhausts, water wetter, engine bay fans etc… help but are not addressing the true issue.
Quite simply in my experience and opinion, the rad is NOT good enough for a high power engine. It is an antiquated copper brass radiator which simply does not cut the mustard any more. I saw 2 Ultimas in Le Mans last week both of which had the back up and had overheated. And know of several other owners who have had cooling problems.
I know some people report no problems but I, and others can not seem to achieve this cool running required.
After considerable research and discussions with various cooling specialists the summary opinions are as follows:
- A 4/5 row rad is too thick to be efficient as the air can not pass through it easily.
- It is heavy
- The factory supplied fans are somewhat lack luster (hence the Profans upgrade)
- The thermostat for the fans should ideally be on the exit to the rad
- There is no drain in the factory rad for emptying the cooling system
- The large end tanks are a waste of space and contribute towards low efficiency
- The mounting angle of 30degrees to the on coming air is not ideal
- Practical and bitter experience shows its not good enough.
I opted for Simon King of Walkers Garage to build the rad for me (www.tecno2.co.uk/radiators.htm) as he provided lots of information and objective advice on the design and has extensive experience of competition radiators. Together Simon and I worked up a new rad design.
The chosen design is a single core 30mm thick ali rad with ~30% more area than the factory rad using 11" SPAL fans as they have the largest CFM ratings ( under impeded conditions as you get with a rad in front not the usual quoted free flow)
This new radiator and fans has now fixed the overheating problems on my car 100%. You can see the temperature fall on the gauge as the fans kick in and it really controls the temperature. It is how the car should always have been. I have no worries in traffic heat or idling at all.
I had 2 radiators made one for me and one for B1 ECC who is reports similar success, particularly on track where the weight saving helps. B1 ECC’s engine now runs at 83degrees (thermostat temperature) on track not above as it used to, indicating under cooling by the original rad.
As you can see the rad is considerably larger
And thinner
You need to make some minor chassis modifications to accommodate the increased radiator size. But so long as you use slightly beefier tubes than the Ultima chassis this does not affect strength.
Anyone interested in more details and drawings drop me an e-mail.
Mark
I got totally fed up with the overheating and all the excuses "the car is not set up properly" "I have no problems" "the rad is big enough". Things like tweaking the idle mixture, getting it as low as possible, ceramic coated exhausts, water wetter, engine bay fans etc… help but are not addressing the true issue.
Quite simply in my experience and opinion, the rad is NOT good enough for a high power engine. It is an antiquated copper brass radiator which simply does not cut the mustard any more. I saw 2 Ultimas in Le Mans last week both of which had the back up and had overheated. And know of several other owners who have had cooling problems.
I know some people report no problems but I, and others can not seem to achieve this cool running required.
After considerable research and discussions with various cooling specialists the summary opinions are as follows:
- A 4/5 row rad is too thick to be efficient as the air can not pass through it easily.
- It is heavy
- The factory supplied fans are somewhat lack luster (hence the Profans upgrade)
- The thermostat for the fans should ideally be on the exit to the rad
- There is no drain in the factory rad for emptying the cooling system
- The large end tanks are a waste of space and contribute towards low efficiency
- The mounting angle of 30degrees to the on coming air is not ideal
- Practical and bitter experience shows its not good enough.
I opted for Simon King of Walkers Garage to build the rad for me (www.tecno2.co.uk/radiators.htm) as he provided lots of information and objective advice on the design and has extensive experience of competition radiators. Together Simon and I worked up a new rad design.
The chosen design is a single core 30mm thick ali rad with ~30% more area than the factory rad using 11" SPAL fans as they have the largest CFM ratings ( under impeded conditions as you get with a rad in front not the usual quoted free flow)
This new radiator and fans has now fixed the overheating problems on my car 100%. You can see the temperature fall on the gauge as the fans kick in and it really controls the temperature. It is how the car should always have been. I have no worries in traffic heat or idling at all.
I had 2 radiators made one for me and one for B1 ECC who is reports similar success, particularly on track where the weight saving helps. B1 ECC’s engine now runs at 83degrees (thermostat temperature) on track not above as it used to, indicating under cooling by the original rad.
As you can see the rad is considerably larger
And thinner
You need to make some minor chassis modifications to accommodate the increased radiator size. But so long as you use slightly beefier tubes than the Ultima chassis this does not affect strength.
Anyone interested in more details and drawings drop me an e-mail.
Mark
I had to chop out the diagonal braces in the front radiator tray and remake them slightly outside the chasis box. One of them is welded in place, the other bolts in. It has to do this as the radiators total width is greater than the radiator box.
Also the radiator mounts in a more production car way with rubber bushes in the frame and ali bosses on the radiator. This gives a good AV mount withouth the maintainence problems I had with the factory mounts which had seized solid and I had to cut them out.
A few hours cutting tubes, welding and tapping and drilling some plates. Do all this work and tack in place before removing the factory braces to maintain accuracy of the chasis.
The radiatr with 2x11" spall fans was about £600 I think. I dont think you actually need these fans as the standard factory fans will work fine with this radiator due to its increased efficiency and size; I am sure B1 ECC is using them on his.
As a point of note, reading the other thread on engine temperatures. This rad will actually reduce engine temperatures rapidly to thermostat temp when moving or if the fans kick in, It is not a case of holding temperatures. I am not using water wetter or fiddling and bellding the system and have a 1:3 bog standard coolant mix. It just worked (my 2pence worth)
Mark
Also the radiator mounts in a more production car way with rubber bushes in the frame and ali bosses on the radiator. This gives a good AV mount withouth the maintainence problems I had with the factory mounts which had seized solid and I had to cut them out.
A few hours cutting tubes, welding and tapping and drilling some plates. Do all this work and tack in place before removing the factory braces to maintain accuracy of the chasis.
The radiatr with 2x11" spall fans was about £600 I think. I dont think you actually need these fans as the standard factory fans will work fine with this radiator due to its increased efficiency and size; I am sure B1 ECC is using them on his.
As a point of note, reading the other thread on engine temperatures. This rad will actually reduce engine temperatures rapidly to thermostat temp when moving or if the fans kick in, It is not a case of holding temperatures. I am not using water wetter or fiddling and bellding the system and have a 1:3 bog standard coolant mix. It just worked (my 2pence worth)
Mark
Edited by adequatespeed on Wednesday 28th June 09:03
Edited by adequatespeed on Wednesday 28th June 09:04
[quote=adequatespeed]
As a point of note, reading the other thread on engine temperatures. This rad will actually reduce engine temperatures rapidly to thermostat temp when moving or if the fans kick in, It is not a case of holding temperatures. I am not using water wetter or fiddling and bellding the system and have a 1:3 bog standard coolant mix. It just worked (my 2pence worth)
Mark
quote]
I just managed the same thing just by replacing the fans with 11" Pacet Thinlines
Lovely rad though!!
As a point of note, reading the other thread on engine temperatures. This rad will actually reduce engine temperatures rapidly to thermostat temp when moving or if the fans kick in, It is not a case of holding temperatures. I am not using water wetter or fiddling and bellding the system and have a 1:3 bog standard coolant mix. It just worked (my 2pence worth)
Mark
quote]
I just managed the same thing just by replacing the fans with 11" Pacet Thinlines
Lovely rad though!!I have replaced the facs to the Pacet pro 10". These were replaced before going to Le mans and I still have a problem. They are rated at 1090 CFM each. Twice the factroy volume. Looks like I will need to go another route with the raditor. the cjoice is now the Route that GTR-Gaz went or this. Not being a welder I would have to pay to have the chaisis modified if I went this method. Looks very good though and the cratftmanship on the rad looks fantastic.
Will have to see. The car is becoming a sink hole for cash and with a new house and a disapproving girlfiend this is an issue that will have to sit for a while. I have learnt how to manage driving in traffic with hot temperatures. I turn the car off before it gets to hot, sit, wait, let the traffic move 4 or 5 hundred yards, start, catch up, stop, turn off and repeat.
Thanks for the details though, I will be in contact.
Scuff
Will have to see. The car is becoming a sink hole for cash and with a new house and a disapproving girlfiend this is an issue that will have to sit for a while. I have learnt how to manage driving in traffic with hot temperatures. I turn the car off before it gets to hot, sit, wait, let the traffic move 4 or 5 hundred yards, start, catch up, stop, turn off and repeat.
Thanks for the details though, I will be in contact.
Scuff
Nice job on the rad... I came to exactly the same conclusions as yourself and did the rad upgrade last summer - almost identical set up with the rad cooked and fitted by Pace Products in Haverhill Suffolk.
I use three Pacet 295mm profans fans, converted to use the uprated (602 model) motors (fan ref PK1111P/602) - looks as though your rad might be wide enough to fit another fan... should you ever need to.
I use three Pacet 295mm profans fans, converted to use the uprated (602 model) motors (fan ref PK1111P/602) - looks as though your rad might be wide enough to fit another fan... should you ever need to.
Mark,
Did you have to make any mods to the front clip with this new radiator? It looks like the sheets that run either side of the radiator when the clip is down would have to be modded? Do you have any photo's?
Where are you in the country as I would like to come and have a look sometime.
Cheers,
Scuff
Did you have to make any mods to the front clip with this new radiator? It looks like the sheets that run either side of the radiator when the clip is down would have to be modded? Do you have any photo's?
Where are you in the country as I would like to come and have a look sometime.
Cheers,
Scuff
You don't have to but I have modded the front air scoops by cutting the sides off and replacing them with sides at an angle to go to the edges of the radiator. This improves airflow and as a bonus prevent air spilling into the wheel arches.
There is no need to do this from a cooling point of view as it works fine without it.
I am in the north west, I will post some more photos when I finish modifying the front bodywork. It has taken 6 months to get round to doing this job
Mark
There is no need to do this from a cooling point of view as it works fine without it.
I am in the north west, I will post some more photos when I finish modifying the front bodywork. It has taken 6 months to get round to doing this job
Mark
Scuff said:
The car is becoming a sink hole for cash and with a new house and a disapproving girlfiend this is an issue that will have to sit for a while. I have learnt how to manage driving in traffic with hot temperatures. I turn the car off before it gets to hot, sit, wait, let the traffic move 4 or 5 hundred yards, start, catch up, stop, turn off and repeat.
Scuff
Scuff
I'm pleased to say my Sport didnt overheat at Le Mans (low tickover) but one suggestion is to change the girlfriend. I did this and although it wont help the overheating potential, the car is a hell of a lot quieter inside!
Mine too, as GF has not been in the car. Though this may change over time. Would not want to change the Girlfriend though. She has not tried to stop me and only comments if I take the car to work and thus waking the neighbours at 07.30 in the morning or brining the car back late at night. Either side of our house the neighbours are of more senior years.
Otherwise she is the perfect GF.
Scuff
Otherwise she is the perfect GF.
Scuff
Well the GF and the car have finaly made an aquaintance. Went to a village fete, where a friend was having his 40th B'day BBQ. Loads of interest in the car. GF was ok with this. Also dissapeared for 40 mins with a mate and took him for a spin, and left her at the BBQ. She's cool with this too. Was invited to go with the Lotus club for a drive and a beer (she's coming also). Going to Kimbolton on Sunday with Tuxman and a few others, she's also coming along. Must have done something right ;-)
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