82 replies to this topic

[JohnTurbo]

The flow is certainly differential Steve.

So the result, old system:-

(This is a 4th gear drag from 3000 rpm upto speed X)




And the same drag on the new system.



The result is 10 degrees off the IAT. - You can see the graph is less steep on the 2nd plot too.

And now for my next improvement I've bought this:-

http://www.ebay.co.u...984.m1439.l2649
(25l/min pump)

To give you an idea, my Aussie pump flows 12l/min @ 5PSI
The Bosch one everyone has flows 20l/min @4.5 PSI
And this one flows 25l/min @11PSI.

Its often stated that the bigger the pump isn't necessarily the better - this may be true for the radiator side as you might not have time to take all the heat out of the water. - But the answer to that would be a bigger rad not reduced flow!
At the heat exchanger it should help by providing more cool water thus increasing the temperature differential which is the main governing factor in heat exchange. - You also want fluids to have turbulent flow for heat exchange, otherwise there is an insulating boundary layer of stationary fluid against the walls of the tubes.

Edited by JohnTurbo, 28 April 2012 - 05:20 PM.

[siztenboots]

is that with a thermocouple or the Tmap sensor, if the latter then you might be seeing the sensor risetime

[14500rpm]

Interesting stuff, how are you logging the temps? I'd like to do something like this when I do my too-tight-to-buy-a-proalloy-rad SC install.

[techieboy]

Via the OBD port from the ECU, by the look of it. Z22SE ECU wont do it though as the only intake temp sensor is pre-charger, so useless.

[14500rpm]

Via the OBD port from the ECU, by the look of it. Z22SE ECU wont do it though as the only intake temp sensor is pre-charger, so useless.

Thanks Techieboy, might have to go back to Plan A which involves digital temp gauges for fishtanks

I seem to remember someone on here moved the IAT sensor to post charger or did I dream it?

[JohnTurbo]

Steve, you could be right - but that could only apply to the old system, as the new one has about a lower gradient. Still, there's a good 10secs+ of acceleration in there, I'd imagine it would react faster than that. You're correct, it is via the OBDII port. Ideally sensors for water in, water out, air in air out would be fitted but possibly a bit OTT unless i was trying to sell the things! IAT sensor being pre-charger sounds pretty pointless!!

[JohnTurbo]

What I'd dearly love is the same test done on a stock car / tuned with stock IC / Tuned with uprated IC / Tuned with ProAlloy CC for some real benchmarking. That would really aid the community!! It would also settle a few arguments. I volunteer my bluetooth OBD reader. Of course you'd then need to know what speed x is, but if you imagine 4th gear, 260bhp and over ten seconds, you probably dont want to know.

[cnrandall]

Did you do any steady state or constant load running?

[JohnTurbo]

I did a few different things to see the effects, including a section of back roads where I knew i could always be on the accelerator or brake. Couldn't get over around 40degrees. Couldn't really give a steady (heavy) load though - no hills round here.

[14500rpm]

It'd be interesting to know how long boost is being made during a spirited drive or on the track, I bet it's a lot less than you'd think. With that in mind I reckon creating more thermal inertia (i.e. more coolant in the system with a large header tank) could be a big help.

[cnrandall]

It'd be interesting to know how long boost is being made during a spirited drive or on the track, I bet it's a lot less than you'd think. With that in mind I reckon creating more thermal inertia (i.e. more coolant in the system with a large header tank) could be a big help.

I worked that out from the data on my car at Brands GP... we were on boost for over 80% of the lap! On the road its a totally different story, and the quantity of water in the system is a factor as you suggest.

[14500rpm]

It'd be interesting to know how long boost is being made during a spirited drive or on the track, I bet it's a lot less than you'd think. With that in mind I reckon creating more thermal inertia (i.e. more coolant in the system with a large header tank) could be a big help.

I worked that out from the data on my car at Brands GP... we were on boost for over 80% of the lap! On the road its a totally different story, and the quantity of water in the system is a factor as you suggest.

Brands is a pretty fast circuit so 80% is probably about as bad as you're ever likely to see unless you're competing at the Silver State Classic or something. I wouldn't be surprised if it was less than 50% at a trackday and less than 25% when you're out for a blast on the road and on it. With this in mind it is possible to look at a charge cooling system as a store of cooling potential rather than aiming for being able to loose masses of heat out of the coolant in a short period of time. As long as you can supply enough cool water for the times you're making boost (say 15 seconds in the minute) then you have the rest of the time for getting it back down again. In this case a larger reservoir could really pay dividends.

[cnrandall]

It'd be interesting to know how long boost is being made during a spirited drive or on the track, I bet it's a lot less than you'd think. With that in mind I reckon creating more thermal inertia (i.e. more coolant in the system with a large header tank) could be a big help.

I worked that out from the data on my car at Brands GP... we were on boost for over 80% of the lap! On the road its a totally different story, and the quantity of water in the system is a factor as you suggest.

Brands is a pretty fast circuit so 80% is probably about as bad as you're ever likely to see unless you're competing at the Silver State Classic or something. I wouldn't be surprised if it was less than 50% at a trackday and less than 25% when you're out for a blast on the road and on it. With this in mind it is possible to look at a charge cooling system as a store of cooling potential rather than aiming for being able to loose masses of heat out of the coolant in a short period of time. As long as you can supply enough cool water for the times you're making boost (say 15 seconds in the minute) then you have the rest of the time for getting it back down again. In this case a larger reservoir could really pay dividends.

For track days forget about that theory, you will heat the water in no time, temp delta in the heat exchange will drop and efficiency will plummet. Also, there are plenty of circuits with higher % WOT than Brands GP.

[JG]

(off topic) I can't have been trying hard enough at Abingdon on Friday. finger dipped the CC tank just after a session. Stone Cold.

[The Batman]

that would depend on whether you are using the header tank as a 'hot' or 'cold' tank e.g. the water filling the header tank up does it come from the manifold or from the cc rad

[cnrandall]

Also, feeling the header tank after you have come off the track and its had a good chance to recover isn't helpful. You want to know charge intake temps! When I was last on the dyno with a 'stock' PA system the car we were running would heat the header tank from ambient to so hot you couldn't hold it in one pull @ 260bhp. After a few mins it would recover, but you couldn't sustain any sensible intake temps for anything other than short periods and we didn't dare do any high power running.

[JohnTurbo]

Im with JG. I cant get the water hot at all. The twin pass rad I have is easily coping. That much was also true at Oulton - Id jump out and the old heat exchanger was pretty warm, but the header tank on the return was dead cold. I have around 10-12 litres of coolant in there. Thats why Ive bought the double power pump, that will ask more or the rad and less of the exchanger. Id say Im on boost well well over half the time on track. - I did manage similar on the road albeit for 2 miles or so. It coped well. The worst response was hitting speed Y. The temp hit steady state...though my lunch wasnt far off hitting my pants.

[JohnTurbo]

I may have to invest in those additional temp sensors. We need these discussions to include quantitative readings!

[JohnTurbo]

Caption:-

Where in hell am I going to mount this?!

[Nev]

Jeeze, that is a big old boy. Most people 'rest' their pumps on the rear subframe lip somewhere, or mount it on the engine side of the vertical boot.