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Re: What did you do to your Fiat lately ?

Posted: Sun Dec 05, 2021 11:59 pm
by Jonohhh
MadFiat wrote: Sun Dec 05, 2021 10:22 pm Mishimoto radiator hoses? I mean while you're in there you might as well.

And yes, you need new flywheel bolts. Modern Performance in Houston has them, pre loctited and everything. https://www.modernperformance.com/

I personally would not really move the IAT / MAP sensor too much as it may be calibrated for its current location.

1. Are radiator hoses a failure point or weakness? Is there a benefit to upgrading them?

2. Fantastic, I'll get those ordered ASAP so I have them when I need them. Thanks a ton!

3. As far as iat relocation, I'm just tired of the absolutely horrendous consistent state of heatsoak. Having to drive the shit out of it for more than a few minutes straight just to get the sensor to read low enough to give me full timing and boost is pretty shit. I initially plan to install the IAT just to take measurements with a multimeter to verify/see where the additional heat is entering the intake system (before tb or after) after being cooled by the intercooler. It's well known that intercooler out temps are far, far below reported iat temps at any given moment, so it'll definitely be some interesting data.

During extended periods of low airflow, I'd expect my relocation to read cooler temps than the engine is actually getting at the port, but it's probably conservative enough that it doesn't matter, and If it's not, hopefully I'll be able to change that in the ECU. I'm just trying to improve the response once air gets moving. At the very least, I'll just take data.

I'm gonna leave the MAP where it is, by making a breakout harness and separating the IAT. This is all time dependant of course, and how much it bothers me once I get the car going again.

Re: What did you do to your Fiat lately ?

Posted: Mon Dec 06, 2021 12:32 am
by MadFiat
Maybe I'll take a picture of where the IAT/MAP is on the 124. It runs so much cooler. I'm not convinced that it's a problem with the location of the sensor though, as much as the intake is just getting that heat soaked. You don't want timing advance if the intake charge is actually that hot.

If the 124 has the sensor in the same place, then it's not the sensor location that's the problem but rather actual heat in the intake. Maybe heat wrap the shit out of everything?

As far as the rad hoses... they're not a known issue.. but since you're in there with a low mile engine, might as well do new hoses at your car's age. And the mishmoto are good hoses.

Re: What did you do to your Fiat lately ?

Posted: Mon Dec 06, 2021 9:51 am
by Jonohhh
MadFiat wrote: Mon Dec 06, 2021 12:32 am Maybe I'll take a picture of where the IAT/MAP is on the 124. It runs so much cooler. I'm not convinced that it's a problem with the location of the sensor though, as much as the intake is just getting that heat soaked. You don't want timing advance if the intake charge is actually that hot.

If the 124 has the sensor in the same place, then it's not the sensor location that's the problem but rather actual heat in the intake. Maybe heat wrap the shit out of everything?

As far as the rad hoses... they're not a known issue.. but since you're in there with a low mile engine, might as well do new hoses at your car's age. And the mishmoto are good hoses.
I'd be interested to see as well. The thing that tips me off about the IAT on our cars is how counterintuitive the readings are, being where extended WOT brings temps down and anything else causes it to skyrocket. It is possible this level of heatsoak is happening, but I'd like to know *where*. I have the stuff I need to insulate my charge pipe, so I'll probably do that at some point too.

Unfortunately I'd imagine that most of the heat going to the manifold is coming from the head mounting flange, and there's not really a lot that can be done about that. The multiair engine moves such little air at idle that it not only spends a lot of time in the manifold heating up, but also likely moves little air by the sensor that is in a little pocket next to the #4 runner.

I'd if I do move it, I'd be logging to know if knock is a problem. Worst case scenario regarding an IAT reading lower than actual temp would be a little bit of knock and then the ECU pulling back in response, of course I'd start by driving lightly and then build up so I can stop if it's excessive.

Increasing airflow around the manifold (the 124 may be better in this regard) could help too but...short of vents I don't think that's all too possible.

I'll check out those hoses, after all, the car is now 9 years old.

Re: What did you do to your Fiat lately ?

Posted: Mon Dec 06, 2021 11:44 am
by MadFiat
FWIW, on my 124, WOT causes the IAT to go up not down. Of course I'm frequently only running 10 degrees over ambient unless it has been idling for a while. It definitely has less of an issue with heat than the 500 does.

Re: What did you do to your Fiat lately ?

Posted: Mon Dec 06, 2021 4:02 pm
by Jonohhh
MadFiat wrote: Mon Dec 06, 2021 11:44 am FWIW, on my 124, WOT causes the IAT to go up not down. Of course I'm frequently only running 10 degrees over ambient unless it has been idling for a while. It definitely has less of an issue with heat than the 500 does.
If that's actually the case... maybe I should try routing the stock intake feed to the back of the motor towards the manifold.... It wouldn't help at a stop obviously but if it helps at all I'll do it.

Edit: it actually does appear that the sensor is in a different place. If I can confirm this and get my OFT working then I could easily apply the 124s iat correction to the 500 with the relocated sensor. This is assuming I ever get a definition file that is at least somewhat put together.

My IATs usually sit in the 40-70 over ambient range.