21 replies to this topic

[pitbull113]

I know I remember reading something about the stock ECU retarding the timing if the engine gets too hot but can't find the info now. Is this true? How hot is too hot? This weekend at Daytona the car was way down on power and the only thing that changed was it was running too hot due to a fan problem. Mine is a '94 if that helps. TIA

[Caveman-kwebb99]

Yes its true in a 99 model I see a drop in power north of 190 and big drop at 210...  Not sure on a 94 but im sure you are losing power at some temp threashold

[James York]

I know I remember reading something about the stock ECU retarding the timing if the engine gets too hot but can't find the info now. Is this true? How hot is too hot? This weekend at Daytona the car was way down on power and the only thing that changed was it was running too hot due to a fan problem. Mine is a '94 if that helps. TIA

The fan gives you zero benefit with the car moving unless you were running continuously on someones bumper.  If it was running hotter than normal for you in clean air, you have some other issue.

[Tom Sager]

I know I remember reading something about the stock ECU retarding the timing if the engine gets too hot but can't find the info now. Is this true? How hot is too hot? This weekend at Daytona the car was way down on power and the only thing that changed was it was running too hot due to a fan problem. Mine is a '94 if that helps. TIA

 

How hot was it running?  Were you in a draft for long stretches or was it hot while running alone?  

[pitbull113]

during the pace laps it got to 220-230, cooled down some but not as cool as when i was running a fan. car was down on power. I lost 6-8 mph between the bus stop and turn one at daytona and the only thing changed between this last race and the one before was I removed the fan.

[James York]

during the pace laps it got to 220-230, cooled down some but not as cool as when i was running a fan. car was down on power. I lost 6-8 mph between the bus stop and turn one at daytona and the only thing changed between this last race and the one before was I removed the fan.

That is too hot and if you were running those temps in clean air, you have something wrong.  And its not the lack of fan function.  (they are not providing any benefit above about 30 mph, hence that is why they are electric or viscous clutch driven to only rob engine power when needed at idle)

 

If you car was running 220 plus, I am sure it was running a non-optimum ecu map pulling timing advance and costing you power.

[pat slattery]

Any one know how hot the temp has to be to pull timing on a 1.6 and what sensor sends that info to the ECU.  Can that be eliminated legally or not

[Jeff Wasilko]

Just get a good radia

 

Any one know how hot the temp has to be to pull timing on a 1.6 and what sensor sends that info to the ECU.  Can that be eliminated legally or not

 

Don't try to out-think the ECU. Just get a better radiator. I was fighting cooling problems in my ITA miata and switched to a Springfield Dyno radiator. I'm now running at 180-190F at the back of the head (compared to 230+ before).

[davew]

  Can that be eliminated legally or not

 

OH, come on Pat, you know the answer to that question !!!!!!!

[pat slattery]

OH, come on Pat, you know the answer to that question !!!!!!!

Dave, honestly I don't know or I wouldn't ask, I have never, ever disconnected any sensor.  I might, if it is legal

[Bench Racer]

Any one know how hot the temp has to be to pull timing on a 1.6 and what sensor sends that info to the ECU.  Can that be eliminated legally or not

Pat, it's the sensor called a thermosensor at the rear of the head. It's got the green electrical plug. Talk to your engine builder, would think that's a responsibility they take on with selling their engine.

[Keith Novak]

Any one know how hot the temp has to be to pull timing on a 1.6 and what sensor sends that info to the ECU.  Can that be eliminated legally or not

I did some searching and someone on an old thread from the prior site tested a 1.6 on a dyno up to 235* and at least claimed to confirm that the 1.6 does not pull timing at higher temps.  They said the 1.8 ECU was smarter but I never did find evidence that it in fact alters the timing at higher temps either.  Lots of speculation all around the interweb though.

[CARacer]

No one else has said this yet, so I guess it has to be me: it's not legal to remove the fan.

 

I have no telemetry on the timing or the ECU, but my Traqmate data shows very clearly that power drops steadily during a race in my 1.6. I assume this is from general heat soak of the intake, the AFM, the whole engine bay, and the intake air. The power drop I see is not as drastic as 6-8 mph, though.

[MPR22]

It is not legal to remove or alter the temperature sending unit or fan for that matter.  99s pull timing when they get hot and that sensor is prone to failure.

[Johnny D]

So just to be clear...

Steve car is a ITA car?,

and no fan is ok or not ?

 

And in SM it is required.

 

I'll open one more can of worm, It's legal to have a switch to turn on and off your rad fan in SM ??

J~

[Bench Racer]

Has anyone with this supposed heat soaked air intake issue installed a thermo couple in the intake manifold (for a test session)?

[Keith Novak]

So just to be clear...

Steve car is a ITA car?,

and no fan is ok or not ?

 

And in SM it is required.

 

I'll open one more can of worm, It's legal to have a switch to turn on and off your rad fan in SM ??

J~

You need to label the switch "Cool Suit"

[pitbull113]

I run ITA and it's legal to remove the fan in IT.

[CARacer]

I run ITA and it's legal to remove the fan in IT.

Oh, I missed that part. Sorry. A friend of mine got DQed earlier this year for not having a radiator fan, so just trying to help people avoid that in SM.

[tburas56]

I have seen lots of dash switches that say fan.