Let's talk about heatsoak

[thefrush]

Ok, so in an effort to combat the ever present issue of heatsoak, I need to better understand what it is and how it works. First off, a general definition of heatsoak; it's basically just high temp intake charges, right? Is this caused by high supercharger/turbo temps, engine temps, or both? What are some ways to combat heatsoak?

We all know about cooling intake charges through inter/aftercoolers, injection, etc... But what about us JR guys who can't run an aftercooler? I've been advised against injection, so what does that leave?

-Thermal coating?
-High performance radiator?
-Venting?

Would these even come close to the effect of an aftercooler that drops intake charges almost 200 degrees? All three of these focus more on lowering underhood temps in general as opposed to cooling the direct intake charge, is that even worth the benefit?

What are some of the drawbacks of heatsoak, besides the obvious decrease in performance? I've heard about problems with fuel and injectors getting plugged, though it was in reference to military vehicles, is this an issue for a track car? I've also heard about causing detonation inside the cylinder due to spontaneous combustion? Any other things to worry about with heatsoak?

Discuss please.

[focusownerskid]

When you're inlet temps go up, your timing has to go down.

So, other than just the thinner, less hp producing air, going into your engine, it is also retarding timing to combat against detonation.

When the block/head get hot, with a roots blower bolted to it, the inlet temps go up further.

A larger more efficient rad, a slightly lower t-stat and some decent electric fanS(not single) to keep the motor happy is a nice addition.

You don't have to worry about deto if you have your tune setup to decrease timing with inlet temps(which is only possible with your IAT in your mani).

Water/Meth is the best way to combat this. Or, if you are daily driving/drag kind of guy, just throw a bit of N2O on top when ya want to get onto the gas a bit

- Drew

[thefrush]

I was advised against injection, so I'm going to try and avoid that.

What about an oil cooler? Is the oil that runs in the JR coming from the engine? In which case, would cooling the engine oil help to cool the JR?

[BUR_ZX3]

Unfortunately, with the JRSC there really is no way to avoid heat problems... compressing air simply creates more heat. same as decompressing air chills it. (hence why air compressor tanks are hot to the touch and those spray duster cans freeze up when you spray em non-stop.)


If you're lookin to go uber custom... I'd tap the manifold, install an IAT sensor and run that... that'll make it so that you possibly have more power @ lower temps, but that the ECU recognizes when the heat is getting to be too much, and backs off to a safe area.

Gettin an oil cooler would be really only advantageous if youre gonna track it hardcore... otherwise its a lot of money for a little gain... and when it comes to keeping the engine cool, you'd prolly find more usefulness there.

[belacyrf]

Treat everything seperately.
If coolant temps are to high, modify your cooling system.
If oil temps are too high, modify your oil system.
If inlet temps are to high, modify your induction system.

They are intertwined, but not to the point where changing one makes a noticeable difference to the other.

[w00w00]

amen. break down your problem into its constituent pieces. you dont want to talk about heatsoak in a holistic manner or youll get too jumbled up in all the variables.

typically people refer to heatsoak in regards to the efficiency of an intercooler. you could say, well, my turbine is glowing red hot, thats obviously a source of higher IATs, lets do something to reduce the heatsoak of the turbine, e.g. water cool your center section. however, a more proper way to look at the problem is as follows. your turbine is part of your air compressor, its job is to compress air, if its operating where its not thermally efficient then you need a new compressor. your intercooler, which comes after your turbine/compressor, is part of your charge tubing, its job is to cool your intake charge. if your ic is heatsoaked then you need to get more, cooler air flowing past it or you need a better ic.

[j20000]

Originally Posted by focusownerskid

When you're inlet temps go up, your timing has to go down.

So, other than just the thinner, less hp producing air, going into your engine, it is also retarding timing to combat against detonation.

When the block/head get hot, with a roots blower bolted to it, the inlet temps go up further.

A larger more efficient rad, a slightly lower t-stat and some decent electric fanS(not single) to keep the motor happy is a nice addition.

I talked to Oscar about this when I bought my JRSC/BBK from him...he said the same thing...The biggest side effect of "heat soak" is retarded timing. With a larger radiator it will help keep temps down, and maintain your timing. He said that with a PWR radiator and 180 degree thermostat a full day of racing never brings the temp gauge over 180. Without it he said he was seeing temps in the 240 range. He also said that although the Zetec cooling system is VERY efficient, and can handle these temps...there is also room for improvement. So that's my next purchase...a PWR rad, and 180 degree thermostat. He also said that another downfall of heat is that since the manifold is aluminum it acts as a heat sink. When the engine is turned off after hard or long driving, the intake manifold actually pulls the heat up from the motor, so its better to keep your engine at opperating temps before racing or dynoing.

[sleeperlove]

why have you been advised against injection?

[w00w00]

honestly i think youre jumbling up a couple different things here. youre talking ect when we're talking iat. yes, the two are related, as belacyrf touched on, but solving the ect issue, while it may lower your iats slightly, doesnt address the problem head on.

however, when we're talking about the jrsc, there are only so many things you can do to lower those iats. thats why i think oscar recommended a better engine cooling system to you.

i think a proven addition to a bbk jrsc is water/meth injection but apparently someone has steered you away from that. curious about why? was it the possibility of rotor degradation? reason i ask is cause there was a guy from texas a couple years ago that put injection on his jrsc, infraredsvt used to be his name but he changed it at one point. i wonder how his blower is holding up?

[j20000]

Originally Posted by w00w00

i think a proven addition to a bbk jrsc is water/meth injection but apparently someone has steered you away from that. curious about why? was it the possibility of rotor degradation? reason i ask is cause there was a guy from texas a couple years ago that put injection on his jrsc, infraredsvt used to be his name but he changed it at one point. i wonder how his blower is holding up?

Once again...Im fairly new to the whole FI thing...so most of my knowledge has been gained on here, or from Oscar himself. I also asked Oscar about water/Meth injection...he said that yes, it is proven to cool IAT's....but water molecules take up more space than air...so he said what you gain in cooling you lose in air volume, since the water is taking up space where air could be. So he said it's pretty much just a waste of money becuase it just evens itself out. I do know first hand that heat soak is an issue..Im not saying that is is like Bigfoot..people talk about it, but it doesnt exsist, because everytime I go drag racing if I dont let the engine cool significantly between runs...every run gets .1 slower.

[w00w00]

i agree, your injection will displace some of your air charge but i dont know that the tradeoff is as even as that, otherwise, yea it would be a big waste of time/money and noone would bother with it. id say the diminishing returns on water/meth are had if youre only running in short spurts with plenty of time in between to cool everything off.

going with your example, lets say again we're at the strip in your car. you take your first run, temps are normal, spraying water/meth will likely have little benefit and will infact displace some of your air charge. but say youre now on your 5th pass, your engine bay is much hotter, your iats are way up, your ecu should be pulling alot of timing to compensate. this is where the water/meth is beneficial. you dont add timing with water/meth, instead you try and get back to your programmed peak timing by lowering iats to safe levels.

dont take this as an affront to oscar or his advice. hes a great guy and knows what hes talking about. i just cant help but see it the way i do until someone can give me a more logical, cogent perspective.

edit- something to note as well. adding water/meth will require some programming to actually maximize the benefit in most cases. this is due to the fact that its typically injected after the maf/iat sensor. therefore the ecu isnt going to see the iat change, and will continue to pull timing.

[DisrupTer911]

this may sound off beat but...

high IATs are result from excess blower heat.

so wouldn't cooling the actualy JRSC lower the IATs?

so wouldn't using something like... this hood help to lower the blower's temp and create lower IATs? I mean, once you get moving and air is being forced in, its going to be substantially cooler air then whats being jumbled around under the hood?

or what about using something like the old FC hood w/ the vent over the airbox to get cooler air into the filter and subsequently into the blower?

[Jaspo]

I don't think you'd see much if any effect on IAT's from lowering your coolant temp. I recall an article about the PW kit that said they had showed a 300 degree reduction in intake temps in some instances. With the high temps you can get from a blower, a 25 degree cooler engine temp isn't going to do much.

I'm doing something similar to what Disrupter spoke of. I have a Kamanari ram air hood and I am ducting half of the air flow onto the top of the PW intake manifold and the other half is ducted to the air filter. I seldom have heat soak issues with the intercooled PW blower, but during last years string of 90-100 days there was some effect. I'm hoping some induction of cooler air may lessen the effects.

With an non-intercooled blower, heat soak will be an issue.

[sleeperlove]

The FC hood with the ram air would be something to look into as well. The cooler the intake charge is before the blower the less it will be heated after it. Also in your search for lower underhood temps you may want to look into ceramic coating your header or heat wrapping it.

[j20000]

Originally Posted by w00w00

edit- something to note as well. adding water/meth will require some programming to actually maximize the benefit in most cases. this is due to the fact that its typically injected after the maf/iat sensor. therefore the ecu isnt going to see the iat change, and will continue to pull timing.

I totally agree with you completely...and the fact that I do agree with you is somewhat of the same reason that I havn't installed a Water/Meth injection yet...I would want to optimze my performance by adjusting my tune and advance the timing to reap the benefits of the lower IAT's, the problem there is that I would have to be running the injection all the time...and what if I run out, or it quits working for some reason...then I am running lean....so I figured I may as well leave it alone. I figured that the cost to benefit ratio of a PWR radiator and thermostat would work just fine with me. If I was into hardcore drag racing, then I would think about going with the water/meth injection...but the fact of it being a daily driver and occasional drag racer...I just cant justify it...however having two seperate tunes may be an option since I have an XCAL2...one with water/meth, and one without. maybe someday. oh...and I used to have a VIS Invaser hood...and I didnt notice any differance...only that you can hear the SC whine better.

[w00w00]

well see thats the thing about the water/meth. most people advise you not to do things like increase timing or boost with just wmi. thats because its meant to be a safeguard only. however, testimonials on snoperformances own site contradict this with people advancing their timing by up to 10 degrees iirc in one example.

i wouldnt run any more timing then you had planned to without the wmi but i would want the tune to be 'aware' of the wmi in the sense that although the iat sensor isnt seeing lowered temps immediately when the injection comes on, the charge temp in the manifold is lower then at the sensor. that way the ecu doesnt start scaling back your timing, because its assuming the charge in the manifold is really hot.

[focusownerskid]

Originally Posted by thefrush

I was advised against injection, so I'm going to try and avoid that.

What about an oil cooler? Is the oil that runs in the JR coming from the engine? In which case, would cooling the engine oil help to cool the JR?

What oil?



- Drew

[thefrush]

I thought the JR had oil in it for lubrication. I guess not.

Thanks for all the info everyone, exactly what I was looking for in this thread.

[w00w00]

i believe it does in the bearing case, but its totally self contained so theres no way to cool it.

[LeadfootS2]

Your ? was on heat soak so that's what I'll talk about. IMO

I like the ducting from the hood to the S/C, that would work.

If you have the $$$ this is what I would do.
1. Radiator
2. Oil Cooler
3. Injection
I had real bad heat soak with my turbo setup, I know it's Apples to Oranges but it's still heat soak.
My charge piping was too hot to touch even when I wasn't boosting and I had no cash.
I tried an oil cooler, it cooled the oil but the hot air was blowing into the bay. I tried slicing the cowl seal off with some success. Then I noticed that my driver side radiator fan was blowing really hot air into the engine bay, so I made a sheetmetal duct to divert that air down and out. That worked to some extent.

Now I have plenty of flow through the engine bay, a Be-Cool Rad, and a larger IC.
No more Heat soak.

[thefrush]

I think a vented hood, PWR Radiator, and 180 thermo should cover me. Thanks guys, continue discussion, I want to know enough about heatsoak to write a Masters degree thesis.

[P-51]

Unfortunately, there's not going to be much you can do. Look at how much money you're looking to spend... wouldn't it be better to sell that thing and just get a PW kit?

This has always been one of the biggest disadvantages of the JR kit from the beginning. Using an undersized blower that is working less efficiently (more heat) and no intercooler was just... bad design.

When you're boosting, that little blower makes a lot of heat, and you cannot get it out of the intake charge. Then, when you're in the pits idling trying to get your engine temps down, the engine heat is soaking up through the intake manifold and into your blower, it will heat up to engine temp, roughly 200 degrees. The only way to cool that thing is drive around off boost, get air flowing through the blower and over it. This kit was really only good to soup up a daily driver for occaisional boosting. It was never going to work for any kind of racing.

The intercooler in the PW kit helps in two ways. First, it obviously directly cools the charge air. Coupled with the larger more efficient blower, this creates huge benefits. The secondary benefit is the AW intercooler sandwhiched between the blower and the intake manfiold acts as a thermal barrier. The engine heat cannot conduct through to the blower, because it's being soaked up by the IC water.

The sad answer is, you can put a lot of extra time and effort and money into that JRSC, and only get marginal improvements. You'd be better off ditching it and getting something better.

The most cost effective thing you could do to improve the situation for drag racing, is do water injection on track, and then come in and douse the blower with water in the pits.

A properly sized IC system on a race car should have temps near ambient on the entire system downstream of the IC. My A/W intercooler box is exactly ambient temp after spending 30 minutes on track, and the charge pipe between the IC and TB is only only luke warm right near the throttle body end because of heat conduction from the TB.