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Intercooler vent

Posted: November 19th, 2008, 11:00 am
by cantfindausername
Hi all,

I'm toying with the idea of making a rear facing vent for the intercooler thats mounted in the boot of my Toyota MR2.

The I/C will have 2 11" fans blowing through the core to keep temps down.

My thoughts behind this idea are 2 fold. Firstly to direct the air backwards rather than just having the air coming down and potentially disrupting airflow. And secondly to act as a heat shield from the large exhaust cans.

I'd like some advice on what thickness & material I should make it out of, and how would be best to protect against exhaust heat.

This is a very rough sketch but should give an idea of what I'm trying to do.

Thanks,
Ant

Re: Intercooler vent

Posted: November 19th, 2008, 2:09 pm
by Julian
Sorry but those diagrams make no sense to me, you will have to elaborate a little (at least for my sake).

Where will the cold air be coming from and where will it be fed to.

Re: Intercooler vent

Posted: November 19th, 2008, 2:44 pm
by cantfindausername
Cold air will be pulled in the Right hand side vent on the car. This was originally used for a Side Mount InterCooler as fitted as stock to these cars. I will remove that SMIC and fit a blanking plate to that vent, this will divert the air up over the wheel arch to the boot area. This is a tried and tested method of feeding cold air to the boot.

The 11" fans will then be used to pass the air over the intercooler core. They should pass enough air over the core to keep the charge air cool.

I know the drawings aren't the best - and looking at them again its quite embarassing. I will try and get some more done in better detail. Working in an IT department though I sometimes get funny looks when I'm drawing car parts!

Re: Intercooler vent

Posted: November 19th, 2008, 3:03 pm
by Julian
So basically the IC will sit above the exhaust cavity? fed with cold air from a side vent?

If that understanding is correct then the intercooled should work quite well. The fans will only really be necessary when the car is stationary as the low pressure area behind the rear valance should do a reasonable job of sucking air past the IC provided there is positive pressure from the side vent.

I had something similar on my X1/9 taking cold air from above the rear wheel arch flares. No fans as the car was for racing purposes only but we did find very substantial temperature differences across the intercooler to the point where it was just above ambient air temperature which is about as good as it gets. We had a CO2 cryogenic system as backup but never got to use it (the one time it was fitted and working it was deemed to be in breach of the racing regulations).

Re: Intercooler vent

Posted: November 19th, 2008, 3:06 pm
by cantfindausername
edit - yes you've pretty much got it Julian.

Hopefully this will explain a little better the idea behind the piece I'm wanting to make.

I will add pictures that Phill Lanes sent me of where he's mounted the I/C which should also help.

Image
Image

The previously attached images just show the general shape of the piece I'm after, and again, a rough sketch of what I have attached here. Now have air lines tho to show the purpose of the piece.

Re: Intercooler vent

Posted: November 19th, 2008, 3:49 pm
by Julian
I would be looking to close the ducting off a bit to ensure consistent flow from your sidevent and avoid unnecessary heat soak from the engine bay but that would otherwise be optional.

It looks as though you should be fine although the IC looks a bit big for road use (sorry I'm not a firm believer in the bigger is necessarily better theory for intercoolers).

Re: Intercooler vent

Posted: November 19th, 2008, 3:58 pm
by cantfindausername
Julian wrote:I would be looking to close the ducting off a bit to ensure consistent flow from your sidevent and avoid unnecessary heat soak from the engine bay but that would otherwise be optional.
Not entirely sure what you mean by that. The side vent will be blanked off, no air from that vent will go to the engine bay, but will all go to the boot area.
Julian wrote:It looks as though you should be fine although the IC looks a bit big for road use (sorry I'm not a firm believer in the bigger is necessarily better theory for intercoolers).
The car isn't really of "road use" spec. Big turbo, big intercooler, big cams, Its a bit of a mish mash between Track & Drag.

Re: Intercooler vent

Posted: November 20th, 2008, 2:48 pm
by Julian
cantfindausername wrote:
Julian wrote:I would be looking to close the ducting off a bit to ensure consistent flow from your sidevent and avoid unnecessary heat soak from the engine bay but that would otherwise be optional.
Not entirely sure what you mean by that. The side vent will be blanked off, no air from that vent will go to the engine bay, but will all go to the boot area.
I understand that the air flow is seperate, it is the heat soaking through the firewall that I would want to avoid and tighten up the airflow you have to make the best use of it.
cantfindausername wrote:
Julian wrote:It looks as though you should be fine although the IC looks a bit big for road use (sorry I'm not a firm believer in the bigger is necessarily better theory for intercoolers).
The car isn't really of "road use" spec. Big turbo, big intercooler, big cams, Its a bit of a mish mash between Track & Drag.
For drag use it isn't going to make much odds, the air flow would be adequate but for track use you may find that the air flow is too small to maintain a consistently cool charge. I have no idea what kind of volume you get into the boot but it needs to be fairly substantial to keep everything happy. The basic idea is sound but my concern is just that the airflow is not going to be enough.

A ducted cover over the IC helps to keep the air flowing straight into the matrix consistently, it doesn't have to be airtight, just closed enough to keep things moving in the right direction. Just remember you aren't trying to cool the entire boot space.

Re: Intercooler vent

Posted: November 20th, 2008, 3:00 pm
by cantfindausername
Thanks Julian. All good stuff to bare in mind.

I'm not sure myself on how much air is going to be passed. The idea initially is to operate the fans via the intact temps.

I hadn't considered heat soaking through from the engine bay to be honest. Perhaps that is something that does need looking at. I'm hoping that the engine bay fans will decrease the chance of that. Maybe I could seperate the I/C section of the boot so that it just channels round from the vent to a "smaller boot" in effect. This should create some space between firewall and Intercooler space.

All stuff I need to look at more closely I think.

Thanks again,
Ant

Re: Intercooler vent

Posted: November 21st, 2008, 9:12 am
by Guy Croft
It might have been better to have a water-cooled charge cooler with its own radiator,

G

Re: Intercooler vent

Posted: November 21st, 2008, 9:43 am
by cantfindausername
Guy, that was the original idea.

I had this monster core to put in...

Image

With a Fiat Cinqucento Radiator mounted up front.

Image

However, I had massive issues with the Davies Craig pump that was used. It was a well spec'd set up, but I never had the confidence in it. I was always concerned about air locks, water leaks and burning the motor out etc. I discussed it with Phill Lanes when I took the car to him the first time and we decided that it would be better to keep the intake system simple and revert back to a large cored intercooler.

I'm paying a visit next week Monday or Friday so will get some bang up to date pictures of how the car is coming along. I might have to pop in to ask directions tho Guy - hope you don't mind?

Ant

Re: Intercooler vent

Posted: November 27th, 2008, 2:14 pm
by Evodelta
I don't like this design at all, it looks terrible, sorry.

Is this the side vent we are talking about here in front of the rear wheel?

http://www.geocities.com/MotorCity/Downs/2156/side.jpg

Apologies for the link (I don't have any personal pics of MR 2s), but I think it shows instantly what we are talking about here.

Re: Intercooler vent

Posted: November 27th, 2008, 2:37 pm
by cantfindausername
Yes, the side vent, but on the drivers side - that will be used to feed air into the boot area.

What part of the design don't you like?

Re: Intercooler vent

Posted: November 27th, 2008, 2:39 pm
by Evodelta
None of it!
I'll type out something more constructive later when I have time.

Re: Intercooler vent

Posted: November 27th, 2008, 2:48 pm
by cantfindausername
thank you Martin, look forward to reading it.

Ant