37 replies to this topic

[The Knobs]

Europeans like them, but everyone here in the UK seams to think they are a waste of time. Anyone got any conclusions whether they are worth trying ? Back to back with a charge cooled car would be nice

[Lps]

isnt bigger always better.....


like you Tim, i cant quite get my head around a bigger cooler being a worthless upgrade. I know there in a shite position, and i know there get bugger all airflow, and i know chargecoolers are the best thing since sliced bread, but i'd have thought the Pro Alloy Cooler + a bigger Intercooler would be the be all and end all?

Plus for those that dont have £2k to spunk on a CC surely a bigger IC is the perfect *make do* upgrade

id love to see someone with emense gonads make a roof pod a la RS200

[The Knobs]

i know the airflow issue, but you stick your face out the window at 60, and there is quite a lot of air forcing its way into your head might well order one from europe at some stage and try it out. I know they wont show good results on a rr due to airflow, but you dont drive on a rr. That speedster in the other thread is not running a cc is it ?

[cyberface]

What if you made the 'ears' bigger? Perhaps someone with CFD software could work it out - it's not something I'm au fait with unfortunately. Any aerodynamic engineers on here?

[Joe-Turbo]

if you look at the first pic you can see this german speedster has extended ears http://www.vx220.org...opic=45718&st=0

[The Knobs]

that car was on here a couple of years ago with the lower side pod extension. I wont be adding any scoops or corn flake boxes onto the car though

[Alex Os]

One of the key factors which contribute to making an air to air intercooler perform well is the overall surface area of the core. There is very little space to fit an intercooler with a suitably larger surface area in the VX without some fairly substantial bodywork mods, so the only option to increasing the size is to make it thicker. The standard unit is about 100mm thick, this combined with relatively poor air feed would mean any increase in thickness is unlikely to offer any performance gain as the airflow to the rear part of the intercooler would be compromised by the warm air from the front part. Very thick intercoolers can slow the airflow down to such an extent that the air will stall almost completely making them practically useless. We have found in our testing that the VXT or turbo charged Elises really benefit from charge cooler as apposed to intercooling once you start to exceed ~250BHP. We spent a fair bit of time looking at the feasability of intercoolers for the VX and concluded that it wouldn't be possible to install an intercooler setup which would be of a suitable size and see the required airflow for anything over 250bhp without some very major bodywork mods. Hope this helps.

[Lps]

fcuk it, im going to get Reverie to knock up a nice pre preg carbon roof pod, that'll work.

[Alex Os]

fcuk it, im going to get Reverie to knock up a nice pre preg carbon roof pod, that'll work.

We have just finished fitting a Exige motorsport body to our S1 Elise which has a jocking great big scope on the roof. A couple of days ago we discovered that over 140mph the bloody thing gets so much lift through it that it bends the mount which holds the hard top on so much that you can get your hand out through the gap. There isnt much on the inside of the hard top to hang on to either.

[The Knobs]

so how come it works for the europeans, that speedster looks to produce the goods ?

[cyberface]

so how come it works for the europeans, that speedster looks to produce the goods ?

There was a cryptic comment by John in the thread linked above... something about how he doesn't think that the continental approach to tuning was how he would want to do things...

Reading between the lines it sounds like the German approach is to boost things well up with the expectation that there will be loads of cooling air constantly present (as per autobahn driving). Over here, the same approach would result in monster intake air temps, overheating, detonation and eventual engine failure - since we have fewer opportunities to drive consistently fast, and there's more stop-start hard acceleration, etc.

I'd welcome a correction by John on this as I didn't quite follow his original post. Certainly there shouldn't be any bullshit figures from German tuners, since there are strict engineering laws on power claims.

However if the entire system is undercooled for general British driving then I guess that's the reason. Airflow at 140 mph on the autobahn is enough to keep virtually anything cool, whereas if I'm using the full 300 bhp doing J turns and doughnuts in McDonald's car park, then cooling becomes slightly more tricky

[The Knobs]

what system does the american 275bhp elise conversion use ?

[Lps]

They use a Spearco I/C Tim Force Fed Elise

going by their you tube video of their 400Hp Elise id say it works fairly well.

[chris]

It is seems that physic laws are different in Europe and in UK ... I use to thought that Uk is a part of Europe, but finally not, On the other side, its normal, because physic laws are different : In UK chargecooler is more efficient, and in Europe Intercooler is more efficient For tuning use of course, because track enthusiastic are all in UK !!

Edited by chris, 26 March 2007 - 11:50 PM.

[Thorney]

Eh? I've not said anything on this thread? I've always said that 'any' additional cooling is a good idea on the VXT regardless of how minimal as heat is such an issue with the car but (and I've been pretty consistent in this if you check my posts): 1. Lotus spent a long time designing the VXT intercooler, indeed there are at least 7 different versions they tried before it was acceptable, Vauxhall went on and on at them about it and refused to accept the car until the situation was resolved (if you remember it delayed the launch of the car). Now Lotus aren't stupid so if they can spend a few quid getting it as best tney can (with GM looking over their shoulder) I'm happy to accept that. 2. I've tried 2 alternative intercoolers that 'dont' require clam shell cutting and neither of them made a blind bit of difference to intake temps on the road or the track, ergo they're a pointless waste of money you might as well stick with the standard IC, I can't believe the air in Germany is any better than here in this respect. 3. I've not tested the larger IC that does require the clam to be cut as the level of modifications to the clam are pretty extensive and for me don't justify the gains, we're talking rear clam and side sill cutting, fixing and repainting, to me thats a pita and not worth doing. (IMO of course). For racing we're not allowed to cut the clams anyway so pointless for any race car development. 4. The CC's are proven over an over again on the road and the track. We've fitted them to French owners cars who all confirmed that they lost power on hot track days without the CC but once fitted they were fine (at least one is a member here, I'm sure if he spots this he'll make a post).

[cyberface]

Eh? I've not said anything on this thread?

Sorry John - I said the comment *linked* above i.e. it was from another thread, about the German stage 3 car.

You said:
I've seen this car in the flesh and it really has been done well however I still think there are certain aspects of how the German tuners approach the car that I do not agree with, Chris I think you're just going to have to accept that just because people approach things differently does not mean that other people are doing it wrong.

That's all I was getting at - no offence or mischief intended whatsoever. I was just interested in your reasons why the 'German approach' was different, and not your style. That's all, nothing malicious or pot-stirring.

[speedster]

Some of the larger air to air charge coolers in use over in Germany (not necessary on a VX) have modified end tanks with internal defectors providing maximum flow over larger core areas. That is the good ones are custom jobs. I even heard of some with carefully engineered and hand assembled core tubes too, insuring charge flow cooling is maximized. You know the Germans love their engineering With air to air charge cooling you need to strike a balance between contact/friction and flow rates, for example the charge can't cool unless it comes in contact with a cooler surface/particle..... Bigger cores if designed badly means a loss of boost at the outlet, meaning you may increase boost at the inlet to compensate, meaning you may have just increased the charge temperature......meaning you may gain nothing! Thicker cores and larger vents if not thought out don't necessary work. With a thick core the air may just travel around the unit taking the path of least resistance. Also you need to understand how the unit is constructed and assembled in order to determine the intercooler efficiently, or go bench test it. Getting hold of something thats already proven is the easiest route. The TMS water to air cooler looks good, though I'd like to see a schematic of the pipework

Edited by speedster, 27 March 2007 - 04:11 AM.

[chris]

Between to add : Light larger Intercooler with two lower vents (for symmetry reason)
and one heavy (estimate weight 15 kg) Intercooler system with hypothetic improvement results (versus Intercooler system), my choice was easy :












But, as said before, Physic laws are not the same in my Country.
So you are right to choose Charge cooler and low torque tuning solutions for your engines ...

I put on this forum several : Gtech curves, magazine articles and video which show European tuned cars performances, but similar evidence (for comparaison reason) are rare on UK side ...

Edited by chris, 27 March 2007 - 09:46 AM.

[Joe-Turbo]

hey chris, I think it was probably one of your posts that I have seen before with every thing being weighed? I dont suppose you know how much the standard full exhaust on the VXT weights by any chance? cheers Joe

Edited by Joe-Turbo, 27 March 2007 - 10:39 AM.

[The Knobs]

After reading the article a few threads below, it looks like the intercooler does work on track. As someone says on there, the german cars have been properly performance tested, so when do the uk tuners get this done then ?