[West oz loti]

Okay guys, bumping this thread as I do believe I have a DIY solution which may be slightly better than previous solutions (without going to a air to water system or misting system)

Now I have done a bunch of research on this as I am about to buy an exige s.

This is what I have found so far;
Going to a aftermarket intercooler(air to air) makes little if no difference, as recovery time has been shown to be critical.
The 2-eleven shroud deleting the scoop, is the best option
The roof scoop does very little
Volume of air increase has the biggest benefits

Now the 2-eleven uses two 4inch (100mm) ducts, one going to each side scoop, this give an area of 15707mm2

Now if I use 4 × 3inch (76mm) two going to each side scoop my area increases by 15%. Eg: 18145.84mm2.

Now to achieve this, I will mount two inlets on each side of the Intercooler by using this flat mounted dual duct (https://www.pegasusautoracing.com/productselection.asp?Product=3629 ) and mounting them onto a flat piece of aluminium (with the back cut away to match the duct) and then fit it to a shallow fabricated aluminum box on the front of the intercooler, replacing the existing shroud, as per the 2-eleven design.

This would also direct the air smoothly onto the intercooler. Then two pipes can be mounted into the side scoops each side.

My only concern is fitting the two pipes down the side of the car to the side scoops, but from pictures I believe they will fit.

When I start the mod I will post pictures. This will probably be april/ june.



Any comments/ suggestions are welcome?

 

[West oz loti]

Considerations

- what is the cross sectional area where the air comes in at the scoop? If its less than what you've already measured you won't be getting the amount of airflow you think you are

- it is believed that the air coming in is also part of engine cooling, stealing enough of it to the intercooler may have an effect on engine temps?

- air coming through the scoop definitely feeds the air intake

- you'll need a shape other than 3" circle if you want to mount even one 3" tube near the face of the intake scoop (unless converting to wide scoop)

Whatever you do, don't just post pics show some data!

If you search the internet, selco and exige.com, all the testing and data has been done;

They swaped out 4 different ICs and changed out the different shrouds and pipes using the same track and same driver.

The 2-eleven shroud with the standard IC gave the best results, I am only suggesting improving on the 2-eleven design by increasing the volume of air.

If you want to stick with the standard setup or go to the gold standard air to water, that is your choice. I am only offering a variation to the best air to air solution shown to date.

Stealing air from the side scoops has been shown to have little impact.

PS, earlier in this thread, it has been shown the roof scoops provides peanuts as volume of air goes. Do your own calculations. The 4inch 2-eleven provides considerably more volume of air than the triple mod of 2x 63mm pipe + the roof scoop.

Link to the study done in the UK; http://www.exiges.com/bb/viewtopic.php?f=12&t=15396&hilit=intercooler+exige

http://forums.seloc.org/viewthread.php?tid=368103&page=1

 

[West oz loti]

Well, aftermarket intercooler might actually help.
https://www.youtube.com/watch?v=htGndR7-1Ic
Given that experiment, I hope the better IC has lower heatsoak point and brings the IAT to under 70c.
I have some reservation about that experiment, though. The hairdryer wasn't as hot as I hoped, no inlet temperature, and maybe there should have been a fan blowing through them. And measure with/without the fan. It does indicate that the aftermarket one cools better, though. Whether it's purely due to higher thermal mass, I'm not so sure, since higher thermal mass means it'll take longer to heatsoak, but it'll also remain at that temperature for longer too cool down as well.

If the hair dryer does indeed pump out 190F(87.8C), resulting heatsoaked temperatures 125F(51.7C) and 158(70C) show clear difference.
I've personally seen IAT reach 210F(99C) with the stock setup and float around 90C at a hot track day. Leaves a lot to be desired...

On a related note, I'll be running supplemental air duct to the IC as well soon.

It was found that some of the aftermaket intercoolers didn't recover as quick as the stock one. This is critical as when the intercooler temps spike recovery is crucial. This actually amazed the testers so they repeated the run again with the stock unit and got the same results. I have linked the threads for your reading in the last post.

Enjoyable reading, the guys really did a good comparision.

 

[West oz loti]

These are good points and may make a difference I really don't know.

All I can tell is that larger volume piping (or more volume ) of air apppears to work better at maintianing IC temps.

The scoops I intend to widen and remove the mesh (fit front ducting). Frank (tag name Ronin)) says mesh blocks alot of air so that will be gone.

So will be addressing both your comments to some degree.

This mod is only pinching 15%:more than the 2-eleven mod which has been done before a number of times with no ill effects.

Anyway I will be giving it a try.



Something else which may also help, is the air ducted to the intercooler will go through the intercooler out then up through the boot lid. This will draw more air from below in the engine bay due to a syphon effect, also the air from the roof scoop is still entering the engine bay.
There is also ducts underneath the engine. I don't believe anyone has done tests to prove this that I know , but from theory (can't remember the name off hand for this effect) a low pressure should be developed at the top of the engine to draw air up. Will see.

 

[West oz loti]

well..To me, I didn't' even have to finish watching video to know the result. :shrug: Yes of course the RLS will be better in this experiment. It has a larger thermal mass. It doesn't reflect real life because it doesn't include any flow though the heat exchanger. The rate of heat transfer "Q" is directly proportional to the mass flow rate of the air though the IC. In this video, the cool air flow rate is zero, so your rate of heat transfer out of the IC "Q" is zero. You can have the biggest IC with the most thermal mass and surface area, after 1 lap you've heat soaked if you don't have any cooling air flowing though it. I really think the biggest improvement for the buck is to increase flow. I'd put a stock IC with big ducts against a big fancy $xxxx intercooler going though the mail slot any day. The most effective part of the RLS kit are the shroud with duct adapters.

I realise a lot of ideas have been put forward and in different situations they may be significant, but with the Exige intercooler design real life experiments show more volume of air lowers exit intercooler temperatures.

Testing has shown Iambatman is on the money with his statement above, ie: why I am trying to get as much air through the intercooler as possible. This applies with any intercooler.

As I said previously the 2-11 shroud has been shown to be the most effective as it supplies more volume of air to the intercooler than the other methods; this is proven. I am only trying to create a design that delivers a bit more.
We can only try and see.

 

[West oz loti]

So make a 4" dual inlets to the IC shrould tmr. My drafter will do it tmr

So HK, are you suggesting you are going to copy the 2-eleven shroud with two 4inch inlets out of carbon fibre?

Cool! (If so a price would be great, very interested)

If so I think also just a straight fibreglass may also work to make the cost competitive.

Thanks HK, you make some nice stuff, bought some of your gear through Fly ( john) in Australia.

:coolnana:

Cheers

 

[West oz loti]

John T has lots of cars and chicks :up:

Any chance of making some 4inch ducts that fit in the side scoops that mount between the bracket and the top of the scoop that takes a 4inch pipe?

This would just finish the whole mod off nicely;
Carbon duct intakes and carbon 2-eleven intercooler shroud.

:bow:
:clap:

 

[West oz loti]

Guys,

You are on the money! I have researched this to death, as I had a SC elise previously and don't want to have an exige that drops performance below my older car due to heatsoak.

I have watched videos where the tempretures are live whilst drivers are circulating the track and temps mimic the acceleration (temp goes up), deceleration (temp goes down). The ability of the IC to recover is critical as even with our mods the IC really still doesn't recieve enough air. Having a greater thermal mass just prevents the IC from shedding the heat quickly when decelerating (which isn't that long in a track situation). This is the only time the IC has time to recover.

Therefore why the stock IC preformed so well. It is surprising and it has nothing to do with quality. It is all to do with the poor location and lack of airflow to the intercooler.

Hence my path of trying to get as much air to my IC as possible.

Some more reading ;
http://www.exiges.com/bb/viewtopic.php?f=12&t=15406

The 2-eleven mod will be my go to mod as it has been proven to be most effective. If I can improve on this I may try my new idea. Although if HKfever can make a 2-eleven shroud out of CF I will be very tempted.

 

[West oz loti]

This is only a draft.....

4" = 101.6mm is very large :crazyeyes

Can you find 4" air dust?

Yep!

4 inch piping is available in silicon and neoprene through specialised performance outlets on the net. If you want to be a cheap skate you can also use ally AC duct, 100mm. Available from a hardware store.

Lotus OEM will sell you a genuine 2-11 shroud and associated piping, but it is a pretty penny! The geniune shroud from lotus is made from ally and welded together, so it is pretty good quality.


By the way the 2-eleven shroud replaces the stock shroud and deletes the roof scoop! NOT added onto the stock shroud.

 

[West oz loti]

If you replace the stock shroud to 211, I assume you won't be making use of the 'mail slot'? Not that it matters too much. It's barely adequate anyway...

Correct.

To be honest, I am still considering buying the OEM 2-eleven shroud. At least it keeps the car (sort of) lotus original.

 

[West oz loti]

1. I will mod the OEM Shroud to fit with the 4" dust and also with the mail slot.

2. 2 Curve Seperators in the Shroud to smooth out the flow.

3. Need to make 2 Side Inner Scoops 4" X 7" open with 4" dia elbow outlet that can house the 4" dust.

What do you think?

This will be good as you have the volume of air from the 2 large 4inch pipes+the roof scoop. My only concern is making it fit.

Normally using the 2-eleven shroud you need to take the boot off going to the roof scoop as it needs this space.

I am all open to new ideas that increase volume of air, if you can make it work and it fits.

Cheers HK!

 

[West oz loti]

Not entirely sure if there's enough space for 4" inlet in the side scoop...
I personally might like to keep and utilize stock side scoops(because I'm weird...

Looking forward to what you can come up with! :up:

I am also weird and like the colour coded std side scoops.

You are right, from my reseach the std scoops need to find at least half an inch. I haven't picked up my car yet as it is on the other side of the country, ( that will be another thread) so can't do accurate measurements.

Some modding of the side scoops will probably be required to space them out slight.

I have seen pictures of 4 inch piping in the scoops with the cover off and I would imagine it is slightly squashed with the cover on.

Fitting 4inch ducts will be challenging, but I have a few ideas.???????

 

[West oz loti]

4" is pretty big, can we settle in 3"?

Hi HK,

The whole reason I want 4inch is it is almost twice the volume of air as 3inch. The 2-eleven shroud (which has 4inch) has been proven to be the most effective ( I imagine because it allows the most air). If we can't have the roof scoop included, delete it (as it is insignificant in volume to the 4inch duct anyway) and just copy the 2-eleven design.

cheers.

I am personally not interested in a 3inch design.

 

[West oz loti]

INTERCOOLERS

You guys seem to be missing the point, no one is saying aftermarket intercoolers are rubbish, in fact it is the opposite. They maybe the gold standard, but without enough air ("air to air" heat exchanger) how do they cool?

They can't!

This is why I am suggesting to maximise volume of air. ALL intercoolers regardless of the brand WILL work better with more airflow.

IE, using bigger ducts.

 

[West oz loti]

I'm sorry, but there is just absolutely no possible way this statement is correct. Simply swapping out the stock IC with an RLS IC would not yield that big of a difference. No intercooler on the face of the planet can absorb as much heat as the Exige engine puts out at at WOT for 20 minutes and not be completely heatsoaked with the amount of available airflow to it that the Exige has. You would need an intercooler the size of the entire vehicle to even come close to making this possible and even then it would be quite a stretch.

While I haven't run the calculations, I would be comfortable in stating that the RLS IC wouldn't even last 5 minutes at WOT before becoming completely heatsoaked under those conditions.

Just because you have more mass does not mean it "wicks away" more heat. It means it can absorb more heat before becoming a radiator. If you have a lack of airflow, it makes absolutely no difference as to how much heat you can absorb once you reach that threshold, you're done. As a corollary to that, with more mass, the longer it takes to shed that heat... so once the RLS becomes completely heat soaked, it will take longer for it to return to a given lower temperature, all other things being equal.

What you CAN do with more mass is add more fins or other surface area to radiate that heat from, which is where you get a better performing IC. But the bottom line is, if you don't have the airflow, the RLS intercooler isn't going to help you much.

I am not saying the RLS IC is bad and no one should buy it (or any aftermarket IC for that matter) ... all I'm saying is that just because the RLS IC is better (lots better) than the stock IC doesn't mean it's going to help you much unless you have more airflow. As someone above said, I'd take a stock IC with 300% more airflow over an RLS IC with the roof scoop airflow any day of the week. Hell, I want an RLS IC myself, but I can't justify the cost since I don't really track my Exige that often. If I had unlimited funds and time, I'd definitely buy a different IC than the stock one.

Exactly!!!

And guess what, it has been proven with independent tests. I included the link, go read and search on exige.com, there is alot more info there about the tests, graphs and videos.

No amount of degrees or chest banging is going to change real track testing with the same car, same driver and same track changing out different ICs.

If the RLS is significantly better than the 4 intercoolers tested on exige.com. repeat the same tests including your IC and lets see the data! Preferably by someone independent.

Blowing hairdryers through them is not the same.

What some are failing to believe is the tempreture climbs very rapidly with full acceleration, only when you brake or coast does the intercooler recover. The lighter, less mass units can shed the heat quicker, this is just thermal dynamics. All this is because there is not enough air.

These are real world tests I have presented, on a track, which is worst case scenario.

If you dispute this;

LETS SEE YOUR DATA!

I would be happy to see the testing (which is now on the table) to be disproved.

:shrug:

 

[West oz loti]

It APK919's way better than adding on the shroud?

Hi HK, APK919 was the one of first to experiment with extra ducting and air, very inventive and probably would be equally as effective in fitting the same size hose to the intercooler shroud.

What I don't know is if 4inch could be fitted there. If you do the calculations 4inch provides almost twice the air volume of 3inch. So 4inch is what would be the preferred option. As per the 2-eleven shroud (by the way it fits perfectly on the standard IC and has the same part no: as the exige shroud)

If it is impossible to replicate the 2-eleven in Carbon fibre I will look at other alternatives. Just let me know.

Cheers for looking into this HK.

 

[West oz loti]

Need to measure the overing area of the oval tube to see the area is equal or bigger than the mail slot (?? in2) + 2 X 4" (25.143 in2).

For 211 copy + mail slot, you need to trim away 1" from the oval rubber tube. Is this OK?

Thank HK,

Best not to worry about connecting to the roof scoop, the area through the mail slot is very small. It is not really worth worrying about when you have 2 × 4 inch pipes connected. I would suggest just replicate the 2-eleven shroud as this should be fairly straight forward and gives heaps more air than other designs to date.

Plus through track testing has shown to preform very well.

Don't know if you know anyone with a lotus 2-eleven, but if they could send you the shroud to borrow, it would be easy to copy

Cheers

 

[West oz loti]

Copy 211 is easy, but doesn't look good with the original oval tube.

What the latest draft is with 2 side 4" inlets + extent the original oval inlet about 1 to 1.5". But buyer need to trim away 1" of the rubber tube

Here is a photo of what a member did on Seloc, homemade 2-eleven shroud. Looks pretty mean to me!

Also triming the bellows will mean you are into the segregated section which will be hard to fit back on the shroud.

After seeing one in a car, what do you think?

This has a heatsheild too. That could be another project for HK!

 

[West oz loti]

I think if I was going to get really crazy Id do the 211 heatshield, with wide scoops completely blocked straight to the ports. Then I would rip out the front oil coolers and do a small top mount oil cooler plumbed to the mail slot. If you want to get really nuts you could put a suplemental radiator in one of the oil cooler spots.


If I wanted to get super crazy over the top nuts I think the car absolutely begs for a front mount A-2-W.


Sometimes I wonder if mid engine is worth all the packaging constraints. What a PITA!

Aschen,

The 2-eleven shroud is absolutely a simple mod, any non mechanical person can do.

The 2-eleven shroud is a stock lotus shroud that fits perfectly onto the Exige intercooler, you can even by the piping from lotus. The hardest thing is to get the glued original shroud off, which is the same with all the aftermarket shrouds. So l am not sure what you mean by really crazy??

Then you feed the piping into the side ducts done! Simple!

The only reason you would fabricate your own or buy aftermarket piping is to save money.

This mod has shown to be extemely effective compared to other options (accept air to water), to me it is simply a no brainer, for such a simple change.

 

[West oz loti]

Also, this has been working wonders for me! I have been debating about adding cooling fans to the back of the IC, but haven't gotten around to it yet, and I don't know where to tap for power...

:coolnana: