BAT’s, what to do

gotovato

Greenie N00B Member
Greenie Member
Hey all, as some of you know I track my car pretty often in the summer. One issue I’ve had is BAT’s getting up to the point where I’m seeing decreased boost and timing(built into my tune of course for safety) after only 2 or 3 laps. On the street this isn’t an issue, 2-3 back to back 4th gear logs and it’s fine, only becomes an issue on track.

Currently rocking a mishimoto J line intercooler. I specifically picked this so I wouldn’t have to ditch my crash bar which I’m not willing to do.

One option would be running a little meth? Small nozzle, not tuned for, just to keep bats in check. I was told to avoid this.

Next option, ducting(which needs to happen anyways) and hole saw my grill to get extra air in there. Might work? Maybe?

Another option, a more efficient/better intercooler that is a similar size to my current? I looked into a vibrant option but it was rated for the same HP mine is, and is only 1.75” taller, all other dimensions were the same so probably not worth it.

Anyone have any suggestions for me? Thanks
 
Ducting, ducting and more ducting.

Do not cut more holes, or allow more air into your engine bay yet.

How much air pressure, or vacuum are you seeing in the engine bay? Have you used a magnehelic gauge to ensure you are passing enough air out of the engine bay?
 
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Make sure that all of the air coming through the grill is being forced through the radiator and intercooler. You should have a diverter to make sure that a high pressure area is maintained in front of the intercooler. Given the opportunity air will just go around
 
E85 an option? With added octane you wouldnt have to worry about high IATs as much from a safety perspective.
 
E85 an option? With added octane you wouldnt have to worry about high IATs as much from a safety perspective.
Unfortunately, no e85 available for me. Pump 94 is what I have, and it’s not even great 94 lol.

Ducting, ducting and more ducting.

Do not cut more holes, or allow more air into your engine bay yet.

How much air pressure, or vacuum are you seeing in the engine bay? Have you used a magnehelic gauge to ensure you are passing enough air out of the engine bay?

so ducting seems to be a popular option among track goers. I haven’t done any testing of any sort, and nothing with a magnehelic gauge. Ducting should go a long way for both bats and coolant temps. Really need to figure out how I can do it.


The OEM pu grill seems to be pretty restrictive. You suggest not cutting it up?

Make sure that all of the air coming through the grill is being forced through the radiator and intercooler. You should have a diverter to make sure that a high pressure area is maintained in front of the intercooler. Given the opportunity air will just go around

so ducting alone will help force enough air through the intercooler that I’ll notice a drop in bats?
 
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Simple ducting around my rad/intercooler sealing it to the grill as best as possible will hopefully be a good start?
 
Have you blocked off your hood scoop?

You would be surprised at how much air that thing forces into your engine bay when you go front mount IC.

It will fuck with you 2 ways, 1) it forces air behind the radiator and can ruin cooling efficiency by creating a high pressure zone behind the radiator. 2) that same high pressure zone can create lift, which will severely affect the handling of the car.

A simple way to test it, use some blue painters tape and line the hood scoop enough to block it and then check BAT's and ECT's. Even if you dont permanently block it off, you can confirm if it's an issue.
 
Have you blocked off your hood scoop?

You would be surprised at how much air that thing forces into your engine bay when you go front mount IC.

It will fuck with you 2 ways, 1) it forces air behind the radiator and can ruin cooling efficiency by creating a high pressure zone behind the radiator. 2) that same high pressure zone can create lift, which will severely affect the handling of the car.

A simple way to test it, use some blue painters tape and line the hood scoop enough to block it and then check BAT's and ECT's. Even if you dont permanently block it off, you can confirm if it's an issue.
That is some very helpful information. I really do need to try and block it off. Might be good for a few degrees. Will have to test that and see
 
Have you blocked off your hood scoop?

You would be surprised at how much air that thing forces into your engine bay when you go front mount IC.

It will fuck with you 2 ways, 1) it forces air behind the radiator and can ruin cooling efficiency by creating a high pressure zone behind the radiator. 2) that same high pressure zone can create lift, which will severely affect the handling of the car.

A simple way to test it, use some blue painters tape and line the hood scoop enough to block it and then check BAT's and ECT's. Even if you dont permanently block it off, you can confirm if it's an issue.
I can confirm blocking off the hood scoop makes a difference. I have a CS scoop, was even running a koyo radiator, and coolant temps would get high. I blocked off with some 1/8" perforated steel (I figured that would allow some air to pass through as if the TMIC was still in place). Bats rarely get above 212 and when it's cool I will cruise at 183/185 where as I was cruising at 207.
 
Or best plan: get rid of pu, replace with Gen win.
Lol yea sure. Will start by blocking the hood scoop sounds like. Just block the opening where the TMIC would seal against and see how that goes? Would probably be better to just block the opening. Less material needed that way ?
 
Lol yea sure. Will start by blocking the hood scoop sounds like. Just block the opening where the TMIC would seal against and see how that goes? Would probably be better to just block the opening. Less material needed that way ?

Yes, just tape up the scoop opening and drive around on a highway or something. Them drive the same route with the scoop open at the same speed and watch BAT's and ECT's so you have equal means of which to measure just that one change.

I wouldnt block it off permanently just yet, because you have to figure out a way to vent heat during stop/go or very low speed driving. The TMIC shroud that goes behind the scoop has slits on the turbo side to vent heat right out of the scoop when stopped. You would need to take that into account if/when you decide to work on your ducting.
 
Yes, just tape up the scoop opening and drive around on a highway or something. Them drive the same route with the scoop open at the same speed and watch BAT's and ECT's so you have equal means of which to measure just that one change.

I wouldnt block it off permanently just yet, because you have to figure out a way to vent heat during stop/go or very low speed driving. The TMIC shroud that goes behind the scoop has slits on the turbo side to vent heat right out of the scoop when stopped. You would need to take that into account if/when you decide to work on your ducting.
well that’s interesting. I figured I could just seal it up and it would be fine? Hmm. Taping the hood scoop is easy enough for some simple testing for sure.

I wish I still had my TMIC shroud so I could see what you mean there. In the spring I guess I’ll play around with it all. Ducting the front end will be interesting aswell
 
@gotovato

Pictures of the shroud under the hood. (Mine has a few drill holes from a project that didnt pan out.)

The vents are towards the back and passenger side. The driver side has too many harnesses and electronics to risk water damage on rain.

General pic
20191129_094958.jpg

Backside by turbo
20191129_095002.jpg

Passenger side
20191129_095007.jpg
 
I definitely removed that piece when I put my bigass scoop on, wonder if I should put it back to maybe protect some shit from the elements...
I have been reading up about how much heat the bigger turbo setups make. I am wanting to find a way to do vents in the hood with expanded black aluminum as the covers but haven’t found a good way to do that and maintain DD friendly qualities.
 
@gotovato

Pictures of the shroud under the hood. (Mine has a few drill holes from a project that didnt pan out.)

The vents are towards the back and passenger side. The driver side has too many harnesses and electronics to risk water damage on rain.

General pic
View attachment 12504

Backside by turbo
View attachment 12505

Passenger side
View attachment 12506

Thanks for the pictures! Now I know what you mean. I’ll have to keep those, but just seal up the scoop opening. First thing I’ll do is test just by taping it off and see what that gets me. Easy enough
 
I have been reading up about how much heat the bigger turbo setups make. I am wanting to find a way to do vents in the hood with expanded black aluminum as the covers but haven’t found a good way to do that and maintain DD friendly qualities.
The heat issues typically don’t appear during regular street use. The difference between street/track driving a car is huge.
 
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