I competed in a time attack race over the weekend.
After driving for about 6 laps around the track, oil temp reached 248F and water temp reached 230F. I cool down whenever I reach these temps. But the problem is that even after cool down laps, RPM doesn't go past 5000 and it moves up very slowly to reach 5000RPM. It feels as though I'm in the safe mode, and the Rev limit got set at 5000RPM. I only experience this when the car has been running pretty hard for a several minutes.

Could this be a spark blow out problem or is my ECU detecting the oil and water temps and trying to go into a safe mode, thus closing my throttle body? I have HKS F con v pro and GTM ECU reflash.

Any input would be very much appreciated.

Jay

 

With a 2003, your rev limiter is a fuel cut so will be completely controlled by the FCON. Perhaps you have temperature compensations in the FCON that are taking effect at high operating temps. Only your tuner would know... One of my gripes against the FCON is that it doesn't even let end users have read-only access so you can see what it's doing.

EDIT: Oil temp is ok, but for a water-based coolant, that coolant temp is approaching the boiling point, even at pressure.

 

Wow, those are high temps. I think the FCON is trying to save your engine.

You should consider upgrading your cooling system and oil cooler.

 

Thanks guys.. I hope it's the F con v pro trying to save my engine as well... I just hope it's not the mechanical issue. I'm gonna meet up with my tuner this week and see what's up.

I have a PWR 40mm radiator, but I guess this isn't large enough for a time attack. I'm going to get the 53mm Koyo R radiator. Also, seems like I'm gonna have to get a larger oil cooler as well... More money in the pit!

 

dont forget a vented hood J! mo money mo money mo money!

 

if you can't go past 5k.. i'm going guess Spark Plugs also

 

i agree with Raj and djamps... seems like you're hitting some of the limits of that are set in the FCON... ask your tuner for the limits set just for information purposes... i wouldn't recommend raising them...

and just for information, you would know it if it were spark blow-out... it would be a very rough running motor...since it wouldn't be firing on all cylinders properly...

 

Already got that~!


Pictures taken by mpact:

 

question is...did you get that?! ^^^^

 

Another thing that might help is the GTM fan kit. Since you already have a bigger radiator i think the hi power fan kit will do more for you.

 

HAHAH~ Unfortunately, NO, I didn't get that..

 

I just thought of another possibility. My front and rear tires were the same size. 265/35/18. What about the possibility of my VDC/TDC engaging in high speed? Of course I had them turned off by pushing the VDC button.. but I heard from somewhere that VDC/TDC still engages even though it's turned off. Any thoughts?

 

Too bad you can't do any datalogging... (getting off the soapbox know - HKS you listening?) Anyway, if your tuner is willing to come out to the track, the F-Con V Pro Power Writer software can monitor speed, rpm, temperature and compensations, timing, boost, injector duty cycle etc via an HKS Pro Dealer’s computer.

 

The funny thing is my HKS tuner WAS at the event! Actually he is in the oranizing committee. But then he was trashed by the mid afternoon... So, when I asked him about it, his response was... "Oh~ really? I'll take a look at it next week..." To say the least, I was pretty pissed...

 

time for a new tuner?

i recommend flying sharif up...

 

I fly coach!

For Time Attack, it's so important to keep your boost levels DOWN if you are running more than 3 laps. I don't care if you have the biggest radiator and fan known to man, you are going to overheat the engine with lots of boost, and lots of hot laps in hot ambient temperatures. Those cool fast Time Attack cars you see in the magazines wont survive for more than 3 laps at full tilt. So I suggest, first of all, keeping your boost in the 10psi or even lower range. Once you have your car, and the track memorized, then it's time to crank up the boost for your 2-3 timed hot laps.

Let me know if you need any help.

 

lol, unfortunately, that is the korean way. i feel for you my brother.

 

I wanted to do what you stated above, but I figured 12PSI was low enough... I guess I'll turn the boost down even more. I ran the morning round at 12PSI. It was sunny and hot, so my Z got too hot after 4-5 hot laps... I was in 2nd place, so I ran 15PSI in the afternoon round, but it was raining, so I ended up getting the fastest lap in the morning round.

Would removing a thermostat help? I do have a pathfinder cooling mod. So, I would be removing two thermostats...

 

I dont think its the VDC engaging. even though its not fully deactivated until you remove power to the bosch sensor behind the hand brake. My guess is that its the Fcon kicking in. Upgraded fans, dif coolant mix might help. Also is heat dissipation is a issue, remove the engine plastics towards the rear of the hood.

 

+1 have the thermostat checked. Maybe it's not fully opening. I wouldn't recommend removing it completely though.

Aside from a possible thermostat or air pocket issue, I think the GTM fan kit is your cure. Wire them suckas to a switch and leave them on the whole race.