Real world effects on performance
02-27-2006, 05:46 PM
#52
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To me it seems pretty simple. The ram air duct does a good job of sucking in air to the intake, but blocks airflow to the radiator... which hence causes the overheating.
Its similar to how in the past people threw on giganto intercoolers on their turbo'd cars, but in turn were hurting overall performance by blocking air to the radiators.
-hS
Its similar to how in the past people threw on giganto intercoolers on their turbo'd cars, but in turn were hurting overall performance by blocking air to the radiators.
-hS
02-27-2006, 06:07 PM
#53
Administrator
Originally Posted by Hymee
C'mon, I didn't say the ram air duct was preventing it revving. I know it is the VDI.
It was wildcard that suggested it
Originally Posted by Wildcard
The VDI valve was not the cause of the initial low top speed. My car topped out at 215km/h (6800rpm) in 6th. Even though the VDI valve was disconnected, at that RPM it was still functioning correctly (i.e. it was closed). Once I changed the intake I got 235km/h in 6th with the VDI still disconnected. Hooking the VDI back up yielded me 236 in 6th and 240 in 5th.
Valid point made I think about the compatability of the ram air intake with the stock air box versus the revi intake.
Big O the area covered by the duct is so small compared to the over all area available for airflow cooling that this doesnt make sense. combined with the numbe rof other people who have the duct and have not had over temp situations make this even less likely in my eyes.
has anyone with the duct logged higher water temps with the scanalyser or harrison?
does wildcard have one oil cooler or 2? did he log his temps previously? what about my other questions in my previous post. did anyone log the temps when he had the intercooler on?
Mark i already said i wouldnt believe it was the screens. Thats me making a point about jumping to conclusions.
02-27-2006, 06:48 PM
#54
OK.
I'm not trying to get in a sh$tfight with anyone. RB make good qaulity products. The ram air duct does a good job at getting air into the engine, and is not an impeditment in that regard.
I do believe the theory that the higher coolant temps caused the PCM to go into a cat protection strategy mode, and dump more fuel in. Hence the drop in power.
With the duct removed, the temps improved, and the problem went away. Apparently.
Aus cars do only have one oil cooler. That migh be why this problem may not have presented on US spec cars. So maybe I should have just posted this in the Aussie forum?
Has anyone done some hi-speed runs in the US, say out in the deserts around Nevada? Legally, of course
Cheers,
Hymee.
I'm not trying to get in a sh$tfight with anyone. RB make good qaulity products. The ram air duct does a good job at getting air into the engine, and is not an impeditment in that regard.
I do believe the theory that the higher coolant temps caused the PCM to go into a cat protection strategy mode, and dump more fuel in. Hence the drop in power.
With the duct removed, the temps improved, and the problem went away. Apparently.
Aus cars do only have one oil cooler. That migh be why this problem may not have presented on US spec cars. So maybe I should have just posted this in the Aussie forum?
Has anyone done some hi-speed runs in the US, say out in the deserts around Nevada? Legally, of course
Cheers,
Hymee.
02-27-2006, 06:58 PM
#55
Originally Posted by Hymee
OK.
I'm not trying to get in a sh$tfight with anyone. RB make good qaulity products. The ram air duct does a good job at getting air into the engine, and is not an impeditment in that regard.
I do believe the theory that the higher coolant temps caused the PCM to go into a cat protection strategy mode, and dump more fuel in. Hence the drop in power.
With the duct removed, the temps improved, and the problem went away. Apparently.
Aus cars do only have one oil cooler. That migh be why this problem may not have presented on US spec cars. So maybe I should have just posted this in the Aussie forum?
Has anyone done some hi-speed runs in the US, say out in the deserts around Nevada? Legally, of course
Cheers,
Hymee.
I'm not trying to get in a sh$tfight with anyone. RB make good qaulity products. The ram air duct does a good job at getting air into the engine, and is not an impeditment in that regard.
I do believe the theory that the higher coolant temps caused the PCM to go into a cat protection strategy mode, and dump more fuel in. Hence the drop in power.
With the duct removed, the temps improved, and the problem went away. Apparently.
Aus cars do only have one oil cooler. That migh be why this problem may not have presented on US spec cars. So maybe I should have just posted this in the Aussie forum?
Has anyone done some hi-speed runs in the US, say out in the deserts around Nevada? Legally, of course
Cheers,
Hymee.
beers
02-27-2006, 07:05 PM
#56
Administrator
im not trying to get in a "sh$tfight" with you either hymee. or anyone for that matter. its just i think there are more questions to be answerd before we come to a conclusion. posting it only in the aussie forum wouldnt do the community at large much good. im suprised you would think that a little questioning should result in isolationism.
now back to business. absolutely the pcm will protect the car in over temp situations seen it happen myself on the dyno.
ive travelled at over 100mph in over 90 F with the duct in place for most of a tank of fuel and not seen increase in temps or any over temp protection scheme by the pcm.
does the area where the duct sit provide even 10% of the overall coolong airflow?
now back to business. absolutely the pcm will protect the car in over temp situations seen it happen myself on the dyno.
ive travelled at over 100mph in over 90 F with the duct in place for most of a tank of fuel and not seen increase in temps or any over temp protection scheme by the pcm.
does the area where the duct sit provide even 10% of the overall coolong airflow?
02-27-2006, 07:12 PM
#58
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Originally Posted by zoom44
does the area where the duct sit provide even 10% of the overall coolong airflow?
02-27-2006, 07:18 PM
#59
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What of my centre of pressure theory, Charlie?
I reckon I have a reasonable theory at to why this area where the duct is located might be important at very high speeds. Airflow through the lower opening could possibly be reduced at these speeds as airflow is diverted under the car, and not into the opening below bumper level.
I reckon I have a reasonable theory at to why this area where the duct is located might be important at very high speeds. Airflow through the lower opening could possibly be reduced at these speeds as airflow is diverted under the car, and not into the opening below bumper level.
02-27-2006, 07:18 PM
#60
Originally Posted by Hymee
Say more than 135MPH?
Wildcard started to get hot before then, but that was the max speed he could get when it was "hot".
Cheers,
Hymee.
Wildcard started to get hot before then, but that was the max speed he could get when it was "hot".
Cheers,
Hymee.
beers
02-27-2006, 07:20 PM
#61
Charlie, OK. Its all good. I hope most of the initial questions have been answered. I really do hope it is appreciated that I brought this up.
10%??? I haven't measured it accurately, but I'd say at least 30% or more from the main grille. Could even be as high as 50%, but untill it is measured, I'm not standing firm on a number. It is bigger in the flesh than I thought from the pics on the web.
I guess I could go measure it up some time.
Cheers,
Hymee.
10%??? I haven't measured it accurately, but I'd say at least 30% or more from the main grille. Could even be as high as 50%, but untill it is measured, I'm not standing firm on a number. It is bigger in the flesh than I thought from the pics on the web.
I guess I could go measure it up some time.
Cheers,
Hymee.
02-27-2006, 07:24 PM
#63
Originally Posted by swoope
on a closed course with a professional driver, my car did 142 in 5th. i would say it was over 125 for about 4 or 5 miles. no problems.
beers
beers
Cheers,
Hymee.
02-27-2006, 07:30 PM
#66
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Originally Posted by Gomez
Without going outside on this wonderfully sunny 22 degree Celsius day and measuring the areas concerned......I'd say yes
This pic taken five minutes ago......
02-27-2006, 07:58 PM
#69
We georgia boys have ran on the track hitting speeds of 127mph and have had no cooling probs at all. We have the Revi's and the ram and various screens oil and a/c condenser. Matter of fact the fans never came on in the pits when we pulled off. Ambeint temps in the 90's. we run hard for about 50miles before we pit.
We are starting to pay attention to oil temps. Some have reported track temps in the 260F range but we are not sure if that is to be concerned about yet. But we are studying this.
I wonder how long he was running at this speed and what his oil temps were especially since he has only one cooler.
Interesting thread.
olddragger
We are starting to pay attention to oil temps. Some have reported track temps in the 260F range but we are not sure if that is to be concerned about yet. But we are studying this.
I wonder how long he was running at this speed and what his oil temps were especially since he has only one cooler.
Interesting thread.
olddragger
02-27-2006, 08:05 PM
#70
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Originally Posted by olddragger
I wonder how long he was running at this speed and what his oil temps were especially since he has only one cooler.
02-27-2006, 08:12 PM
#71
Thanks for the info, olddragger. All good info.
127MPH is 204km/h. Wildcard topped out at 215km/h (133MPH) with the duct on (VDI off), 235km/h (146MPH) with the duct off (VDI off) and 240km/h (149MPH) with the VDI on.
Ambient temps in the 90's F = 32 C, so that is comparable.
Agreed, I wonder how much affect the extra cooler would have. Yes - it is an interesting thread
Cheers,
Hymee.
127MPH is 204km/h. Wildcard topped out at 215km/h (133MPH) with the duct on (VDI off), 235km/h (146MPH) with the duct off (VDI off) and 240km/h (149MPH) with the VDI on.
Ambient temps in the 90's F = 32 C, so that is comparable.
Agreed, I wonder how much affect the extra cooler would have. Yes - it is an interesting thread
Cheers,
Hymee.
02-27-2006, 08:24 PM
#72
Administrator
Originally Posted by Hymee
Charlie, OK. Its all good. I hope most of the initial questions have been answered. I really do hope it is appreciated that I brought this up.
.
.
always was all good
of course its appreciated .the oil cooling is a concern and has been for some time. remember all the bad engines last heat wave in Las Vegas nevada Phoenix Arizona and elsewhere? MOST (a few exceptions like 2 or 3) were on our Autos which only had one cooler. this is very likely one of the root causes with the oil way over temp and cooking off. had MNAO been forced to accept 4port ATs again this year(along with the new 6port 6AT) they would have had 2 coolers. There may still be a "retro fit " kit coming for folks with oil issues in these hot areas of the states. You me mez and a freind of ours here in the states could have a long chat about that.
02-27-2006, 09:00 PM
#75
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Originally Posted by zoom44
'mez thats not very nice rubbing it in
we just have had a period of some 80-90 days rain and cloudy with no break except for @2 days 3 weeks ago.
we just have had a period of some 80-90 days rain and cloudy with no break except for @2 days 3 weeks ago.