High speed instability? Buy a radiator.
Discussion
Having spent a lot time and effort over the years trying to cure heat soak issues, radiator recored, thermal lagging, smaller number plate modwise electricary etc. etc. I pretty much got it as good as it was going to be without going down the road of fancy rads and bonnet venting.
All the mods did really, were make it cool down more rapidly once moving but did pretty much sod all when stationary which is when the problem occurs. I knew that I was getting lots of cool air into the engine bay when moving as my water temp guage would get wind chill and read as low as 70 degrees on the motorway, especially after fitting the fibreon lip spoiler which dramatically dropped the gauge reading by another 5 degrees when moving at speed but did sod all for my high speed instability issues which is why I fitted it in the first place.
After 2 years my recored rads has started leaking again, and I had my arm twisted into buying a shiny Radtec ali rad (ok maybe i didn't need that much convincing into buying more bling for my toy
)
Today Dulfords fitted it and I have noticed two very distinct changes to the car;
The water temp sender no longer gets chilblains at speed and now reads sensibly. I guess with the new radiator having a fully enclosed cowl only the air needed for the engine coolant(governed by the fans/fan aperture) is getting into the engine bay from this route, although this doesn't appear to have made the heat soak any worse.
And secondly Which leads me onto the point of this thread, the car now feels more stable at (excessively) high speeds
, and I don't mean "some slight improvement" it was quite noticable how much more planted the car felt.
So, in our efforts to improve air flow into the engine bay (without providing an improved exit route), are we actually contributing high speed instability that many of us have suffered from?
Big thanks to all at Dulford's for another job well done again
All the mods did really, were make it cool down more rapidly once moving but did pretty much sod all when stationary which is when the problem occurs. I knew that I was getting lots of cool air into the engine bay when moving as my water temp guage would get wind chill and read as low as 70 degrees on the motorway, especially after fitting the fibreon lip spoiler which dramatically dropped the gauge reading by another 5 degrees when moving at speed but did sod all for my high speed instability issues which is why I fitted it in the first place.
After 2 years my recored rads has started leaking again, and I had my arm twisted into buying a shiny Radtec ali rad (ok maybe i didn't need that much convincing into buying more bling for my toy
)Today Dulfords fitted it and I have noticed two very distinct changes to the car;
The water temp sender no longer gets chilblains at speed and now reads sensibly. I guess with the new radiator having a fully enclosed cowl only the air needed for the engine coolant(governed by the fans/fan aperture) is getting into the engine bay from this route, although this doesn't appear to have made the heat soak any worse.
And secondly Which leads me onto the point of this thread, the car now feels more stable at (excessively) high speeds
, and I don't mean "some slight improvement" it was quite noticable how much more planted the car felt.So, in our efforts to improve air flow into the engine bay (without providing an improved exit route), are we actually contributing high speed instability that many of us have suffered from?
Big thanks to all at Dulford's for another job well done again
Very interesting stuff Hamish.i noticed that the only time the windchill affected the temp sender on mine,was when the fans are on,i proved this by going on runs with the fans disconnected,and i wouldn't happen.The car would just sit happily at the thermostat temp.It sounds like the better cooling is keeping your fans switched off,possibly?
.i noticed that the only time the windchill affected the temp sender on mine,was when the fans are on,i proved this by going on runs with the fans disconnected,and i wouldn't happen.The car would just sit happily at the thermostat temp.It sounds like the better cooling is keeping your fans switched off,possibly? unclemark123 said:
OscarT said:
Who can supply the Radtec ali rad and how much?
i paid approx £400 for mine from act. bluebottle, not sure about the high speed stability, but improved cooling manners .....
agreed, best thing i have done to my carOscarT - TVRCarParts supplied mine at similar price to Act.
OscarT said:
Who can supply the Radtec ali rad and how much?
Presumably Radtec 
although i prefer Docking's stuff .. we've found it lasts much longer on our race car and Dockings are stunning at turning work around quickly when we need it. When the head gasket went on our racer it pumped enough pressure into the radiator to blow it up like a balloon and still it doesnt leak! Dockings are the business imo 
,very pleased to find it!spend said:
Just to clear up my confusion, are you saying you had no cowls around your fans originally, and that the 'wind chill' of the temp sensor is down to not having cowls?
Dave
Original rad and fan mounts had no cowling, so air was allowed to pass through the entire area of the radiator unrestricted. Dave
So I am assuming that the cowling on the new rad is reducing the amount of free flowing air hitting the front of the engine(temp sender location), as the temp guage reading is no longer as susceptable to high speed wind chill.
Edited by Bluebottle on Sunday 12th August 11:25
Bluebottle said:
Original rad and fan mounts had no cowling, so air was allowed to pass through the entire area of the radiator unrestricted.
So I am assuming that the cowling on the new rad is reducing the amount of free flowing air hitting the front of the engine(temp sender location), as the temp guage reading is no longer as susceptable to high speed wind chill.
Do you have a serp or pre-serp,Hamish?So I am assuming that the cowling on the new rad is reducing the amount of free flowing air hitting the front of the engine(temp sender location), as the temp guage reading is no longer as susceptable to high speed wind chill.
In that case i reckon your gauge is reading better because your fans aren't coming on,due to improved cooling-sounds like the rad is a good improvement.Both of my serp griffs suffered from 'windchill',and both had the std factory rad cowling,so would be essentially the same set up as yours,but both had std TVR rads,and the fans are often on,even on the run.
The interesting thing,is that the temp variations you can see on the gauge,are often not really happening.I did a series of experiments comparing the actual coolant temp(read through my Omex ecu)to the gauge indicated temp.In some cases i saw variations from below 70 to 95 on the gauge,yet the actual temp never changed,and was sat at the thermostat temp!All caused by windchill and heat soak!
The interesting thing,is that the temp variations you can see on the gauge,are often not really happening.I did a series of experiments comparing the actual coolant temp(read through my Omex ecu)to the gauge indicated temp.In some cases i saw variations from below 70 to 95 on the gauge,yet the actual temp never changed,and was sat at the thermostat temp!All caused by windchill and heat soak!
You could well be right Mike, without the tests you did its not possible to know if the fans are running when driving at speed, although I had never noticed them running at full speed when slowing down to a speed where you could hear them in the past.
Either way I think we are both agreeing that less cooling air is entering the engine bay at speed, which is why I was thinking that maybe this was a contributary factor to high speed instability.
Either way I think we are both agreeing that less cooling air is entering the engine bay at speed, which is why I was thinking that maybe this was a contributary factor to high speed instability.
Bluebottle said:
.......
Either way I think we are both agreeing that less cooling air is entering the engine bay at speed, which is why I was thinking that maybe this was a contributary factor to high speed instability.
Either way I think we are both agreeing that less cooling air is entering the engine bay at speed, which is why I was thinking that maybe this was a contributary factor to high speed instability.
,very much so,it sounds like you've certainly discovered something there.With properly set suspension geo,i've not had the instability that you sometimes hear of.some get it,and some never get it. spend said:
So you are saying you still got that problem with the cowls Mike (sorry my brain is very sloooow this am!)
Hi Dave,yes you still get the problem with the cowls,and only when the fans are running,hence i reckon Hamish's nice new rad may be cooling enough to stop the fans coming on,when on the run.On both of the serp griffs i've had,this has been an observation,but i'm sure the a/c doesnt help,as this brings the fans on even when extra cooling isn't necesary.spend said:
BTW Mike, I have a spare dizzy mounted ign. amp if that chap needs one - you're up here this week I hear, welcome to borrow it if you want.
Dave
Thanks for the offer mate,i'll pass it on if he gets in touch.Dave
I thought my 'visit'(or rather the reason for it) was supposed to be top secret!
Bluebottle said:
You could well be right Mike, without the tests you did its not possible to know if the fans are running when driving at speed, although I had never noticed them running at full speed when slowing down to a speed where you could hear them in the past.
Either way I think we are both agreeing that less cooling air is entering the engine bay at speed, which is why I was thinking that maybe this was a contributary factor to high speed instability.
Not so Hamish Either way I think we are both agreeing that less cooling air is entering the engine bay at speed, which is why I was thinking that maybe this was a contributary factor to high speed instability.
I had Carl Baker wire in me a fan over ride switch with an LED which lights up every time the fan kicks in
Most useful if cooling is a big part of your life Hamish Gassing Station | Griffith | Top of Page | What's New | My Stuff