Cooling a Supercharged S4
#61
Rennlist Member
Hi Juju,
I know mine is a different kit, with different components, but here's a picture of my left wheelwell IC. Also my fans.
Good luck,
Dave
#62
Developer
They just called & said the large fan mounted to the rear of radiator was PUSHING rather than PULLING air. Surely this contributed to the cooling problem! They are rewiring it. We will see what difference it makes.
#64
Nordschleife Master
Did you get the rear seal behind the thermostat checked?
A lot of shops don't notice it even when replacing the thermostat, so unless you tell them specifically that its there, they probably missed it.
If that seal is ok too, and your needle is consistent, I'd leave the car as-is for now and just drive it.
#65
I drove the 928 into work this morning in peak hour stop/start traffic. The temp gauge remained halfway between 85 and 90. So it seems that fixing the wiring on the larger of the three fans fitted to the rear of radiator (so that it pulls) and adding a bottle of "Purple Ice" have made a significant difference. I'm still minded - if it's possible to do so - to relocate the IC radiator to the wheel well and to add a big pusher fan to the front of the condenser.
Hilton: Andy from Rennsport had limited time to work on the car yesterday so he only performed an oil & coolant service and inspected the car to identify any major problems or maintenance issues. He suggested I drive it and monitor how it goes because the fan-issue was probably a major cause of the cooling problem. The wait period to get the car back into Rennsport is >1 month so I'll book it in for a thermostat replacement and anything else that can/should be checked at the same time.
How difficult is thermostat + rear thermostat seal replacement? Maybe I could have a crack at this?
Andy also found that the supercharger intake pipe had come off so there was no boost (I had thought the car felt sluggish to when I test drove it). The guy who regassed the AC pulled some of the SC hoses off to access the AC valves etc and obviously forgot to reconnected this main pipe. It's safe to say the car feels a lot more powerful now although the clutch is clearly not up to handling the power and slips under moderate-to-heavy acceleration.
Hilton: Andy from Rennsport had limited time to work on the car yesterday so he only performed an oil & coolant service and inspected the car to identify any major problems or maintenance issues. He suggested I drive it and monitor how it goes because the fan-issue was probably a major cause of the cooling problem. The wait period to get the car back into Rennsport is >1 month so I'll book it in for a thermostat replacement and anything else that can/should be checked at the same time.
How difficult is thermostat + rear thermostat seal replacement? Maybe I could have a crack at this?
Andy also found that the supercharger intake pipe had come off so there was no boost (I had thought the car felt sluggish to when I test drove it). The guy who regassed the AC pulled some of the SC hoses off to access the AC valves etc and obviously forgot to reconnected this main pipe. It's safe to say the car feels a lot more powerful now although the clutch is clearly not up to handling the power and slips under moderate-to-heavy acceleration.
#66
Rennlist Member
We advised you that something was clearly not right and glad it was as simple as a fan spinning the wrong way.
Run the car and find its new limits before pulling anything else apart. Whereas it is possible more than one thing is wrong at a given point in time the probability of such has to be low. In your hot season I expect you will find limits to how far you can push the car but in your neck of the woods if you push a stock 928 you risk jail never mind with such a power adder on top- especially when it is sealed an d might actually work!!!
It is not a big job to pull the thermostat and take a look at the seal it sits on [not the body seal ring] - they can get very ratty although how and why defeats me.
If you find in due course you are not satisfied with the cooling you can always consider a revamp but do the easy things first- some of which you have already achieved by the sound of it.
Your immediate problem now is the clutch [if it is slipping]. If you see smoke from the rear of the car it is the tyres that are slipping [ha ha]! A clutch that cannot grip is just a plain waste of time all round.
Sounds as though you have probably converted an expensive hair dryer into a rocket ship!
Rgds
Fred
Run the car and find its new limits before pulling anything else apart. Whereas it is possible more than one thing is wrong at a given point in time the probability of such has to be low. In your hot season I expect you will find limits to how far you can push the car but in your neck of the woods if you push a stock 928 you risk jail never mind with such a power adder on top- especially when it is sealed an d might actually work!!!
It is not a big job to pull the thermostat and take a look at the seal it sits on [not the body seal ring] - they can get very ratty although how and why defeats me.
If you find in due course you are not satisfied with the cooling you can always consider a revamp but do the easy things first- some of which you have already achieved by the sound of it.
Your immediate problem now is the clutch [if it is slipping]. If you see smoke from the rear of the car it is the tyres that are slipping [ha ha]! A clutch that cannot grip is just a plain waste of time all round.
Sounds as though you have probably converted an expensive hair dryer into a rocket ship!
Rgds
Fred
#67
Well said Fred
I'll find out what power it's generating when I get a dyno tune on the Autronic SM4.
Traction is very easy to break in 1st & 2nd even with a slippy clutch. An upgraded clutch will only exacerbate this haha some nice sticky tyres will help.
I'll find out what power it's generating when I get a dyno tune on the Autronic SM4.
Traction is very easy to break in 1st & 2nd even with a slippy clutch. An upgraded clutch will only exacerbate this haha some nice sticky tyres will help.
Last edited by juju; 06-11-2015 at 05:45 AM. Reason: error in description
#68
Rennlist Member
By the way do you have a fuel pump fitted that can support 500 or whatever bhp? Do you have a super MAF fitted that can read the airflow correctly? John Speake will correct me if I am wrong but as I recall his work the stock MAF system runs out of air measurement capability at about 450 crank BHP [the voltage signal to the LH is maxxed out]. If this is not controlled you can easily create a lean condition and that is not good. I understand Carl took care of all these things in his top end kit but in your position I would want to know they are fitted and working- apologies if I have missed anything along the way.
A dyno session should tell you most of what you need to know- try to make sure they log the AFR as well if possible on that rig. Folks like Hilton or John Gill will likely be able to advise you as to how the numbers stack up against other dynos.
If and when you get the full Monty out of that setup I reckon it is going to be quite scary initially- especially if you are driving around on bars of soap masquerading as rubber!
Rgds
Fred
#69
Nordschleife Master
Andy also found that the supercharger intake pipe had come off so there was no boost (I had thought the car felt sluggish to when I test drove it). The guy who regassed the AC pulled some of the SC hoses off to access the AC valves etc and obviously forgot to reconnected this main pipe.