Preparing car for heavy road course duty

[pcdrj]

pcdrj: When you say "lean conditions" ...

Saleen S/C with MAF right after filter. Normally IAT reads below 110. In August we were seeing IAT reaching 140-150 and a bunch of timing was being pullled out. We did not datalog but you could definitely feel it. We upgraded to Revan IC (2x larger with dual fans) which seemed to manage heat soak much better. Spent alot of time on dyno with hot tuning using 93 octane. I agree with your comment about 100 holding power a little longer before timing comes out.

I'm done for this season but we may datalog next year if we have issues. Again, maybe a little over cautious but I don't to lose another motor.

 

[SoundGuyDave]

Yeah, I have the original motor still in mine, and want to keep it there for a while!!

If I were you, I would research moving the IAT sensor to one of the intake runners, in the base of the blower. You'll have to re-scale the IAT maps, but your tuner should be able to do that with no issue. A lot of the Whipple blower guys do that mod. It's pretty simple, as well: drill and tap the manifold part of the blower for a stand-alone sensor (Termi part, IIRC), cut the two IAT wires in the harness leading to the MAF housing, and extend them to the new IAT sensor. Done.

You'll get much more accurate readings there than up front by the filter housing. Letting the tune base it's timing and fuel maps on the IAT up front like that is asking the computer to "guesstimate" what the actual air-charge temp is, and if you changed the IC out to a more efficient unit, that will invalidate the thermal assumptions built into the tune. Reading them directly, however.... Whole 'nother story. More accurate (safer) assessment of proper timing and fuel curves will mean that your motor will last longer.

 

[Kaldar142]

How can I monitor IATs?

 

[Vapour Trails]

How can I monitor IATs?

Using an interceptor gauge or your tuner (which isn't practical).

IMO moving the IAT is far more of a safety benefit when you aren't using an intercooler. A good intercooler will remove 85% of the heat gained during compression.

 

[SoundGuyDave]

IMO moving the IAT is far more of a safety benefit when you aren't using an intercooler. A good intercooler will remove 85% of the heat gained during compression.

You are quite correct, however heat soak becomes a major factor when you're pushing high-rpm/high-boost for longer periods of time. While the efficiency ratio won't change, the relative temp differences will, reducing the actual charge temperature drop. Monitoring post-intercooler IAT is still the most accurate info you can give the computer to do the timing and fuel. Think about it this way: why do drag guys ice down their intakes in between runs, when they're only going to have the engine hammering away for 12 seconds or less? We're running ours almost flat out for nearly 20-30 minutes at a shot...

 

[Kaldar142]

Where is the IAT sensor located?

 

[SoundGuyDave]

Stock, the IAT sensor is co-located with the MAF sensor. Since in most systems that places it before the compressor and intercooler, you can see where my concern would be... The fix, IIRC, is to take a MAF sensor for a Termi car, and install it in one of the manifold runners so that it sees the "processed" air-charge temp, and just cut and extend the wiring from the OE MAF sensor location to the new AIT sensor. It will require re-scaling the AIT function in the tune, but...

 

[Kaldar142]

oh ok cool, in my procharger system it has it right before the TB then... so i'd guess i'm good with that

 

[SoundGuyDave]

Just checking: The Procharger setup uses a "blow through" MAF design? IOW, they relocate the MAF housing to right before the throttle body? If so, then you should be fine. If, OTOH, they have the MAF right after the air filter, and before the compressor, you are still subject to the issues discussed...

 

[Kaldar142]

its a blow through so yes its literally right before the throttle body

 

[Racer X]

Brenspeed sells their Vorturd kits with an IAT sensor (Ford part) and a Ford two wire harness. You drill a hole in the underside of the factory manifold at cyl. #2, then tap it. Screw in the sensor, plug the harness into it, run the wires over to the MAF harness, cut two of the wires and solder it in. Supposed to be the right way with a blower.

 

[JA BoostedSTANG]

i as well would recomend a accusump they seem to work very well and are fairly easy to install.