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Old 01-20-2014, 11:23 AM   #1
WAM
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Default High IAT's

I recently bought a 1.6 car with an M45 JRSC. Put the small TDR pulley and TDR heat shield on it and converted it to E85. Made it's first partial pulls on the tuner's dyno yesterday and he was alarmed that it had IAT's of 200 -- the highest he had ever seen for this type of setup. Hasn't even done a full pull yet.

The original pulley gave just 5 psi. I imagine this one is only 6 or so. That's not much pressure. What's the deal with the high temps?

This is for autox only use. I doubt at those speeds I'd be able to push much air thru an intercooler. And I shouldn't have to. Looking for background and been-there-done-that's.
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Old 01-20-2014, 11:32 AM   #2
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Meh.

On track I saw temps in excess of 150degC, goes with the territory of no IC and a low efficiency supercharger.

As long as you tune appropriately there's no big deal.

If it really bothers you fit water injection.
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Old 01-20-2014, 12:06 PM   #3
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I run water injection and track a lot. High IAT's is not the path to power of course. But as long as det is under control . . . . There is something to be said for the maintainability and radiator efficiency that comes with not having IC and piping all over the place. Everything's a compromise.
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Old 01-20-2014, 01:20 PM   #4
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unintercooled supercharger - high IAT's
they go together hand in hand. intercool it or spray the house down to cool it
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Old 01-20-2014, 01:30 PM   #5
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Okay, so the readings aren't a surprise. Is there a consensus on how high an IAT is safe for a solid E85 tune? I know he plans to pull timing at high temperatures. And I imagine we're tuning fat since it's a trailered autox car. No concerns for economy and such.
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Old 01-20-2014, 01:35 PM   #6
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high AIT is high AIT.

if your question is "how hot can I run and not blow up on e85" then the answer is "pretty hot"

but here's the thing: you're gonna make dick for power with 200+ AIT's, and running the e85 super fat and pulling a ton of timing you'll probably end up with STOCK power. And that's not even an exaggeration. so either intercool, or spray some e85 into there, but either way you gotta drop those AIT's.

why do you think we hate on superchargers so much around here?
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Old 01-20-2014, 02:57 PM   #7
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Don't expect spraying water, alcohol or E85 into your intake tract to have much, if any, effect on IAT. It doesn't.
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Old 01-20-2014, 03:02 PM   #8
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Quote:
Originally Posted by hornetball View Post
Don't expect spraying water, alcohol or E85 into your intake tract to have much, if any, effect on IAT. It doesn't.
This.

Depending where you spray it can cool off, but really just ignore IAT,just ensure you're not encounting detonation.

With e85 your det resistance will be far far higher!
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Old 01-20-2014, 03:56 PM   #9
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Quote:
Originally Posted by hornetball View Post
Don't expect spraying water, alcohol or E85 into your intake tract to have much, if any, effect on IAT. It doesn't.
wait wat?
am I missing something?
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Old 01-20-2014, 04:56 PM   #10
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Quote:
Originally Posted by 18psi View Post
wait wat?
am I missing something?
??
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Old 01-20-2014, 07:14 PM   #11
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Quote:
Originally Posted by 18psi View Post
wait wat?
am I missing something?
They both have cooling effects, particularly if they're injected upstream of the valves.

But doing that reduces the effect they have on det resistance.

So pick lower IATs for whatever that's worth, or greater det resistance.
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Old 01-20-2014, 07:35 PM   #12
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well he already has det resistance with e85
now he just needs to cool the charge

and unless I'm mis-understanding you guys, spraying water/e85 just before the IM should drop his temps at least 40* when in boost.

so if he doesn't want to intercool, I don't see why that's not a valid idea

And the reason I think its a terrible idea to just run the e85 and not do any charge cooling is because I tried that on my MP62 and once AIT's were in the 200-230 range the car didn't make jack diddly squat for power. it was truly sad
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Old 01-20-2014, 07:36 PM   #13
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In my fairly substantial experience with water/alcohol injection, I'll just flat out tell you that it has almost no impact on IAT. The only exception would be alcohol injection pre-compressor. Anything post-compressor doesn't have enough time to phase change and the droplets will be injested into the cylinder in liquid state. The phase change from liquid to vapor state during the combustion cycle gives detonation resistance (alcohol will also combust if there is enough free oxygen).

The hype about "chemical intercooling" is just that, hype.

Don't believe me? Try it. Log it.

To make power from injesting a cooler, denser mixture, you need an intercooler. Period. And, yes, I still don't have one. Spending too much time at the track and changing out fluids, brake pads and front hubs.
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Old 01-20-2014, 07:43 PM   #14
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Meh, I don't know nor care enough about it to argue with you, so I guess you're right.
I just know high AIT's suck, so OP should most definitely intercool his setup esp since he'll be tracking it.
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Old 01-20-2014, 08:01 PM   #15
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A TRD heat shield will help a little. So will getting a cooler intake charge by redoing the placement of the intake. The stock intake placement on the Jackson racing kit is terrible.

But you are going to be chasing small gains.

I am fighting the same battle. Making gains, but I am considering doing water injection pre-charger and possibly a small intercooler.

Last edited by verch101; 01-20-2014 at 08:13 PM.
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Old 01-20-2014, 09:33 PM   #16
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Quote:
Originally Posted by 18psi View Post
I just know high AIT's suck, so OP should most definitely intercool his setup esp since he'll be tracking it.
From what I've learned so far, I'd agree with you if I tracked it. But I have to think autox will be another thing since full throttle will be in relatively short bursts. And I get a few minutes cool-down between runs.

So perhaps I will occasionally touch 200, but I hope the large majority of each lap will be cooler.

I found some stick-on temp indicators at McMaster that will let me know what my max surface temps are. Not as good as data logging, but maybe useful.
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Old 01-20-2014, 10:11 PM   #17
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Quote:
Originally Posted by hornetball View Post
In my fairly substantial experience with water/alcohol injection, I'll just flat out tell you that it has almost no impact on IAT. The only exception would be alcohol injection pre-compressor. Anything post-compressor doesn't have enough time to phase change and the droplets will be injested into the cylinder in liquid state. The phase change from liquid to vapor state during the combustion cycle gives detonation resistance (alcohol will also combust if there is enough free oxygen).

The hype about "chemical intercooling" is just that, hype.

Don't believe me? Try it. Log it.

To make power from injesting a cooler, denser mixture, you need an intercooler. Period. And, yes, I still don't have one. Spending too much time at the track and changing out fluids, brake pads and front hubs.
I dug up a old link for a somewhat related thread Joe made over on M-net supporting this. Interesting read: http://forum.miata.net/vb/showthread...rative+cooling
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Old 01-20-2014, 10:12 PM   #18
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I promise you after about 30 seconds of WOT you will be in the 200 range and unless you pop the hood and direct a giant fan at the bay you will stay there for each run afterwards.

Your definition of "cool off" is our definition of "give it time to really heat soak".

Because that's exactly what will happen.
You need to intercool if you want to do it properly.
But hey, do what you want.
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Old 01-21-2014, 07:23 AM   #19
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Quote:
Originally Posted by 18psi View Post
Your definition of "cool off" is our definition of "give it time to really heat soak".
Yeah, in this instance, cool down would actually mean driving around out of boost to get cold air into the blower and lower it's temp.

Popping the bonnet and shutting down the motor will only help if the wait is of a decent length of time - and you're not in the desert....
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Old 01-22-2014, 08:57 PM   #20
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Worried about low speed and an IC? Run a setup like mine. With the fan and sealing the hell out of it it stays pretty cool even at low speeds. And this is with 14 psi so my outlet temps from the blower are probably higher.

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