Forced Induction Interchillers

[GenF-GTS]

Xpuffin said:

How long can you hold wot before iats become high enough to pull timing.
(Appreciate its a difficult question to answer but possible if you base it on the car you have used in the video, as we can already see iats in the mid 40s after 14 secs.)

We don't do much drag racing over here, the only real application for most of the forum members track wise is a standing mile event.

Based on the correction map at 55c the car is pulling timing out, if you have no chiller you will be pulling timing out very soon after nailing it.
Have not done a mile event so i cannot tell you, what i can tell you is if you install a reservoir and get your fluid temp down to 0c and you have enough volume you will have 0c coolant entering the blower for the entire mile.

Its a simple calculation based on pump speed per min versus coolant volume.

The point is at the end of the day you want to be cooling the air charge, with the chiller the air charge is never going to reach "non chiller" air charge temps....if performing the same task over and over.

eg on the video posted previously we have a 6.5L reservoir and with the reservoir and the chiller being so cold, we turned the chiller off and continued to bypass the front HX for another 6-7 dyno pulls just to get the intake temps back to normal "non chiller" temps.

If you're doing a mile race install a reservoir and have much colder coolant passing through for longer.

Another example is this video 20sec after the pull which is 0-225mk/h the IAT is back down to 18c, this is 2 videos on the same day on same road about 10min apart left screen is with the chiller turned OFF and right screen is with it turned on.

http://www.youtube.com/watch?v=pZQ7zX4Oz4g

The other thing about the chiller holding temp really well, we can be on the highway with cruise control on, switch the chiller off and still be below the ambient temp for another 15-20min. Once the chiller is cold it stays cold really well.

[AngryMidget]

GenF-GTS said:

correct you do not get hot when stopped in traffic, recently we had a customer at the drags on a 30c day and his intake temps were 10c whilst waiting in the pits with the car idling for 20-40min between runs.

When you go WOT without the chiller your temps increase quite high then with the chiller they do not go anywhere near as high and you have more ignition timing as it's not being removed since you are at a lower temp in the IAT table. So you gain HP.

I think you might know where I am going with this but hear me out. Sat in traffic the other day for about 20 minutes in 13C ambient temps, my IAT1 climbed up to the mid 60s due to the heat soaking of the air pipe. Obviously, as soon as I pulled away and started pulling more air through the temps dropped fairly rapidly, but in this situation the chiller has no affect on IAT1, and minimal affect on IAT2 due to the boost bypass being open.

Extrapolate this to the start of a run and you are starting from the line already heat soaked for the first 60' or so whilst the charge cools all the parts down again. Granted any loss here will be made back at the top end and more, but netter not lose that loss in the first place I guess which then leads me on to my next question. Would water jacketing the intake pipe to prevent it getting heat soaked in the first place be of much use as it would also provide a colder, denser charge of the air to the rotors to begin with?

[GenF-GTS]

AngryMidget said:

I think you might know where I am going with this but hear me out. Sat in traffic the other day for about 20 minutes in 13C ambient temps, my IAT1 climbed up to the mid 60s due to the heat soaking of the air pipe. Obviously, as soon as I pulled away and started pulling more air through the temps dropped fairly rapidly, but in this situation the chiller has no affect on IAT1, and minimal affect on IAT2 due to the boost bypass being open.

Extrapolate this to the start of a run and you are starting from the line already heat soaked for the first 60' or so whilst the charge cools all the parts down again. Granted any loss here will be made back at the top end and more, but netter not lose that loss in the first place I guess which then leads me on to my next question. Would water jacketing the intake pipe to prevent it getting heat soaked in the first place be of much use as it would also provide a colder, denser charge of the air to the rotors to begin with?

IAT1 is at the MAF, the reason this is getting hot is not the air temp it is surrounding engine bay heat being thrown at the intake pipe from your thermofans, the sensor is metal it absorbs that temperature it has no relevance to air temp at this point, as soon as you tip into the throttle air will start cooling IAT1 down which means cooling the sensors down this may take 10 min of driving to remove heat from the metal sensor....However your ECU doesn't give a toss about IAT1, it's not important the only thing it cares about is the temperature of the air entering combustion which is IAT2. You can't possibly think that your IAT1 "actual air temp" is say 50c after you start driving again and have air flow, i've seen mine take a full 10min to get back down to the normal highway temp it sees....this is a hot sensor and not hot air.

The air temp is not 60c it's impossible, it's also impossible for the air temp at the MAF (IAT1) to be above ambient but the sensor is always slightly above ambient as surrounding engine bay heat is changing the temp of the sensor, air flow is constantly moving the sensor isn't so the sensor heats up, your actual air will not heat up very much pre supercharger as it's moving too fast compared to the sensor which is fixed.

As said the ECU only cares about IAT2 as it is the most crucial of the 2 temperature readings, IAT1 could be 10c and IAT2 could be 120c it only makes decisions based on IAT2.

Water cooling your intake pipe "may" have a slight benefit but as explained it's not really "highly" needed.

[Xpuffin]

GenF-GTS said:

Based on the correction map at 55c the car is pulling timing out, if you have no chiller you will be pulling timing out very soon after nailing it.
Have not done a mile event so i cannot tell you, what i can tell you is if you install a reservoir and get your fluid temp down to 0c and you have enough volume you will have 0c coolant entering the blower for the entire mile.

Its a simple calculation based on pump speed per min versus coolant volume.

The point is at the end of the day you want to be cooling the air charge, with the chiller the air charge is never going to reach "non chiller" air charge temps....if performing the same task over and over.

eg on the video posted previously we have a 6.5L reservoir and with the reservoir and the chiller being so cold, we turned the chiller off and continued to bypass the front HX for another 6-7 dyno pulls just to get the intake temps back to normal "non chiller" temps.

If you're doing a mile race install a reservoir and have much colder coolant passing through for longer.

Another example is this video 20sec after the pull which is 0-225mk/h the IAT is back down to 18c, this is 2 videos on the same day on same road about 10min apart left screen is with the chiller turned OFF and right screen is with it turned on.

http://www.youtube.com/watch?v=pZQ7zX4Oz4g

The other thing about the chiller holding temp really well, we can be on the highway with cruise control on, switch the chiller off and still be below the ambient temp for another 15-20min. Once the chiller is cold it stays cold really well.

Appreciate your post, perhaps i worded my question badly as you haven't answered it.
In you video the chilled iats rise to 45ish c in a 14 sec pull. I get the baseline starts lower due to the chillercooler doing its job but how long can you hold wot (Ie the mile) before the temps need spark control or are you saying the chillercooler can hold temps for the entirety of the run.

[AngryMidget]

Xpuffin said:

Appreciate your post, perhaps i worded my question badly as you haven't answered it.
In you video the chilled iats rise to 45ish c in a 14 sec pull. I get the baseline starts lower due to the chillercooler doing its job but how long can you hold wot (Ie the mile) before the temps need spark control or are you saying the chillercooler can hold temps for the entirety of the run.

AIUI, all depends on how big your reservoir is and whether there is enough coolant to only pass through the intercooler once.
(Theoretical numbers)
IE: 12s pass on the 1/4 mile. Pump flows 1l/s. You would need a 12l system of coolant for the coolant to only pass through the intercooler once during the run, and thus temps shouldn't rise into spark retardation territory.

[Xpuffin]

AngryMidget said:

AIUI, all depends on how big your reservoir is and whether there is enough coolant to only pass through the intercooler once.
(Theoretical numbers)
IE: 12s pass on the 1/4 mile. Pump flows 1l/s. You would need a 12l system of coolant for the coolant to only pass through the intercooler once during the run, and thus temps shouldn't rise into spark retardation territory.

That only addresses the return temperature of the interchiller coolant.
Not what I'm asking, I want to know when, using the coolest interchiller fluid temps possible on a wot run, and for the duration of that run, the iats rise to a level that would result in retardation.
I ask this because on a 14 sec wot run the temps rose very rapidly to 45ish and showed no signs of slowing.
The majority of the guys over here never need to contend with 35c oats on a regular daily basis during a commute nor do they drag race the car. Therefore I'm guessing that a fair few would be considering this system for events like Thunder Road where I'm yet to be convinced it would make much overall difference.
But I'm sure given a turbo type inter cooler system the results would be significantly different as the inherent weakness will always be the valley inter cooler itself.

[AngryMidget]

Xpuffin said:

That only addresses the return temperature of the interchiller coolant.
Not what I'm asking, I want to know when, using the coolest interchiller fluid temps possible on a wot run, and for the duration of that run, the iats rise to a level that would result in retardation.
I ask this because on a 14 sec wot run the temps rose very rapidly to 45ish and showed no signs of slowing.
The majority of the guys over here never need to contend with 35c oats on a regular daily basis during a commute nor do they drag race the car. Therefore I'm guessing that a fair few would be considering this system for events like Thunder Road where I'm yet to be convinced it would make much overall difference.
But I'm sure given a turbo type inter cooler system the results would be significantly different as the inherent weakness will always be the valley inter cooler itself.

Gotcha, will double check my logs from Thunder Road to see if I have IAT2 logged, not sure I do have though. I don't remember too much timing being pulled though, and that was a hot day.

It does in part answer the question in that the coolant temperature going into the intercooler will still be very cold, but the roots blowers inefficiencies start to make themselves known as they compress the air in the manifold/against the intercooler producing a lot of heat, hence my direction of going for the screws.

Edited by AngryMidget on Tuesday 23 February 17:13

[AngryMidget]

Yup, no IAT2 logged (IAT1 of 26), but interestingly, the stock tune for the VXR8 does add timing below 35C of up to 4 degrees!

Looking at my data, only 1.5 degrees of timing were being pulled at 5836rpm in 5th towards the end of the run, got 1 degree KR straight after that till the end though but hadn't disabled burst knock retard by that point so not sure what caused that. What it does indicate that on the LSA at least, is that no timing was being pulled due to IATs, as the first cell to pull timing is at 40 degrees and that pulls 3 degrees.

You do have to remember that this is a factory setup blower though, so should be capable of a full run without overheating. Or so you would hope.

EDIT----

Actually, the RPM multiplier is @ 0.5, so IAT2 was therefor around 40 degrees at the end of the mile in the first band of timing being pulled.

Edited by AngryMidget on Tuesday 23 February 17:41

[anonymous-user]

The assumption that the valley heat exchanger is a weakness is not entirely true. When my engine was run on the engine dyno, it was found that intake temps could be kept under control with an endless supply of cool water. Problem being, the circuit heats up and loses efficiency.

With a large reservoir I could see how this system would work well. One thing I do know is outside a certain operating range, all types of PD superchargers turn into heat pumps, even twin screw types.

[AngryMidget]

Yup, they just have a habit of heat soaking with no airflow over the ic. Which is where the chiller comes into it'sown really.

[anonymous-user]

At VMax, I saw AITs of 230 deg. Not because of heat soak. Mine was overdriven though at the time.

[stevieturbo]

wormus said:

The assumption that the valley heat exchanger is a weakness is not entirely true. When my engine was run on the engine dyno, it was found that intake temps could be kept under control with an endless supply of cool water. Problem being, the circuit heats up and loses efficiency.

With a large reservoir I could see how this system would work well. One thing I do know is outside a certain operating range, all types of PD superchargers turn into heat pumps, even twin screw types.

it's entirely true.

A heat exchanger designed to cool inlet charge....mounted right in the valley of an engine already running at 100degC, also pumping all that heat into the heat exchanger at all times.
So not only does it need to deal with hot air, but heat from the engine.

Screw types are more efficient in the hot air department, but ultimately heat exchanger is still in a bad location, so it needs to be incredibly efficient to stand any chance, or as you say have a huge supply of cold water.

Obviously if you have the aircon system cooling the water, that has to be a bonus. Other than that, simply having the largest possible air/water core up front is the best solution. This will add water to the system, plus offer as much cooling as possible to the water in the system.

If there is a chiller unit present, "cold" water from the front rad could then be cooled further prior to the valley heat exchanger.

Or to keep it all simple, screw all the complication and just use water/meth. ( and a large water rad of course, along with high flow pump system )

[AngryMidget]

I think all options together give the best outcome, only relying on the water/meth at full boost

[GenF-GTS]

Xpuffin said:

Appreciate your post, perhaps i worded my question badly as you haven't answered it.
In you video the chilled iats rise to 45ish c in a 14 sec pull. I get the baseline starts lower due to the chillercooler doing its job but how long can you hold wot (Ie the mile) before the temps need spark control or are you saying the chillercooler can hold temps for the entirety of the run.

Well the thing is our car is built for drag racing it makes over 700hp at the wheels we are spinning the living sh *t out of the blower so it makes plenty of heat, there is a "safe" range that you are suppose to over spin the LSA blower by...we are spinning it much more than that with ours and one day it will likely give in, blow up or do a blower bearing. We already know this.

This video is when the LSA blower was stock, the car had only a tune and a pod filter you can see the IAT2 on a 36c day with a 1/4 mile run around the 2:40sec mark http://www.youtube.com/watch?v=KGAyIYlCXvY

As you can see when the blower is being spun at the normal speed making 9.5psi it doesn't rise very fast and the IAT also only peaks at 29c even though the ambient is 36c so we are still below ambient.

You can also see in this customers car who is manual his IAT2 doesn't peak as high due to gear changes over a 1/4 mile.
http://www.youtube.com/watch?v=wCG-kwkVEH0

In terms of mile racing I cannot tell you what the peak IAT2 will be as I have not held the throttle open for that long i think it's around 30 sec of WOT.

What I can tell you is with the interchiller and a medium sized reservoir your IAT2 will be much lower over the mile than not having an interchiller, if you get an interchiller and are wanting to do mile racing there are a couple of things you should be doing, 1 get the fastest intercooler pump you can we recommend the Stewart EMP from Lingenfelter, install a 6-10L reservoir and then also monitor the intercooler fluid temp before it enters the blower (between chiller and blower)

The temp of the fluid entering the blower will be able to tell you if you have enough coolant volume to avoid that coolant going at or above the ambient temperature, the goal would be eg 25c day to have the coolant be below or peak at 25c at the end of the mile. If possible based on the size of the reservoir it would be nice for the coolant to be 0c the entire mile.

So your only variable will be the reservoir and as said if you are putting lets say 0c coolant into the blower for the entire duration of the mile then the car will be faster and make more HP.

This would be versus having no interchiller your coolant would 1 be very hot before you start the mile race and 2 would loop the entire fluid loop several times, the cooling being applied would only be brief and would only be to the effect of whatever the ambient temp is, the ambient temp would also not be able to cool say 50c fluid back to 25c....it would likely cool 50c fluid to say 45c.....however once that fluid makes it's 2nd or 3rd pass of the coolant loop all of a sudden your 50c coolant is now 70c and 80c the more passes it makes.

In terms of the IAT table removing timing based on the IAT2 temperature this is all going to be dependent on how you tune the IAT2 table, one would assume that if you have a chiller and are participating in mile racing you would have the car tuned and thus the IAT table would also be tuned to 1 take advantage of the cold temps the chiller provides but 2 also not be as aggressive at removing timing when it gets hotter as the stock IAT table removes far too much timing than what is required. A decent tuner would be able to perform this for you so you gain timing when cold and dont remove excess amounts of timing when hot. The adjustment for IAT timing advance/retard is every 5 Celsius so you would tune on the dyno to have the most timing and HP possible for every 5 degrees of temperature increase.

At the end of the day if you size your reservoir correctly you can have 0c coolant passing through the blower for the entire mile. This versus your HX which is simply going to go from warm to hot to very hot over the space of the mile. The car with the chiller will be faster.

The other thing we are yet to try but will be an additional advantage will be water injection combined with the interchiller, water is great at lower IAT, EGT's and combustion temps along with gaining HP, this would then be cooling the actual hot source "the rotor group" and allowing even colder intake temps. We have a friend who has installed water injection it doesn't work as well as the interchiller but he has lowered the peak IAT2 by 12c. When you compare this to the chiller on our car as shown in the video posted previously we are peaking at 79c without the chiller and 45c with the chiller so we have reduced the intake air temp 2 by 34 degrees celsius and as said we are spinning the living sh *t out of our blower so it makes loads of heat to give you an idea the guy we know with water injection is at 28% over drive of the blower we are nearly double that percentage.

I personally do not like the idea of water/meth or meth only injection as it is corrosive and has been shown to strip the teflon coating on the rotor group. Do a quick google image search "methanol blower rotors"

Edited by GenF-GTS on Wednesday 24th February 00:58

[Boosted LS1]

AngryMidget said:

I think all options together give the best outcome, only relying on the water/meth at full boost

You can have progressive water injection. It's really simple and carries no real weight.

[AngryMidget]

Boosted LS1 said:

You can have progressive water injection. It's really simple and carries no real weight.

It was more the consumable nature of it

[Boosted LS1]

I get you

[stevieturbo]

GenF-GTS said:

I personally do not like the idea of water/meth or meth only injection as it is corrosive and has been shown to strip the teflon coating on the rotor group. Do a quick google image search "methanol blower rotors"

If you believe it may cause harm to the rotors, then dont inject prior to the rotors....simplez.

Although it's almost baffling here that the naysayers as to this interchiller...are almost the same people who have been crying for an interhciller on the forum for months, if not years ! lol

Nobody is saying it is the ultimate be all end all solution...but there is no question it will improve things vs water coolant only.

[MildlyAnnoyedMidget]

stevieturbo said:

GenF-GTS said:

I personally do not like the idea of water/meth or meth only injection as it is corrosive and has been shown to strip the teflon coating on the rotor group. Do a quick google image search "methanol blower rotors"

If you believe it may cause harm to the rotors, then dont inject prior to the rotors....simplez.

One of these would do the trick surely? Just change the nozzles? http://www.nitrousoutlet.com/lsa-blower-spacer-nit...

[GenF-GTS]

injecting meth directly into the intake port is only going to result in you getting the benefits of higher octane the cooling effect of the intake air isn't going to be much.

You are also married to methanol injection systems, if you simply plug it in and drive and it injects at WOT you actually lose HP as the air fuel mixture is richened up too much, you have to remove some of your "normal" fueling to compensate for the methanol.

Something goes wrong during WOT like the pump for the methanol fails, you get a leak etc you then get divorced from the system in a big bang. Unless many safety parameters are in the system to return the ECU back to normal fueling.

Like i said though you are married to the system it needs to be working all the time at WOT any failure of a meth injection system isn't good.

The best thing is with the interchiller the temps are a massive reduction and there is no maintenance of it at all, loads of reviews and cars on our facebook now too. 1 car also competes in 1000m sprints you can read his review here: http://www.hsvforum.com.au/showthread.php?15040-Fo...
His car is now the fastest HSV in Australia Holding the record over 1km.