260 cup exige anyone?

[The Pits]

Anyone getting one of these or has anyone driven one?

I wonder if it's really any faster than the 240bhp cars? Hopefully it is. I love all the carbon bits, esp. the carbon spoilers, dash and roof scoop.

claimed weight is 860kg, which if true is a pretty impressive reduction but I think that means no aircon which isn't practical on an exige.

I'm unreasonably obsessed with ordering one (i'm very happy with my elise and love driving without the roof) but it would need to be significantly faster than the 240 exige to justify the extra money.

[TOENHEEL]

Im not to convinced that it will be that much quicker really if comparing the 220 to 240 theres nothing in it on the road. The weight might make it feel even better than it already is through the bends though.

[JPF40]

The Pits said:

Anyone getting one of these or has anyone driven one?

I wonder if it's really any faster than the 240bhp cars? Hopefully it is. I love all the carbon bits, esp. the carbon spoilers, dash and roof scoop.

claimed weight is 860kg, which if true is a pretty impressive reduction but I think that means no aircon which isn't practical on an exige.

I'm unreasonably obsessed with ordering one (i'm very happy with my elise and love driving without the roof) but it would need to be significantly faster than the 240 exige to justify the extra money.

I thought the weight was 890kg? And for 14bhp, I don't think its a big enough jump from the 243 bhp offered from the performance option on the Exige S.

[The Pits]

apologies, it is 890kg, down from 935kg quoted for the exige S.

not a bad reduction but I bet that doesn't include aircon which comes in at 15kg.

[squirejo]

I can tell you that my exige 240R is not noticeably faster in a straight line (on a circuit) than a Exige 220S and hence I would wonder whether a 260 would be any different until well into 6 figures, by which time the straight may be coming to an end. HP = straight line speed, torque and factors like grip = acceleration out of the bend.

[Scuffers]

I think the problem here is that these cars depend so much on the intercooler, and given some beans for more than a minute, it's so massively heat-soaked, as to be next to useless.

[TOENHEEL]

squirejo said:

I can tell you that my exige 240R is not noticeably faster in a straight line (on a circuit) than a Exige 220S and hence I would wonder whether a 260 would be any different until well into 6 figures, by which time the straight may be coming to an end. HP = straight line speed, torque and factors like grip = acceleration out of the bend.

Makes you wonder if blowing loads of money on tuning the 220 is worth it unless your going up to 280 maybe. I find my 220 is more than fast enough on the road, not a great deal keeps up unless its something else a little tasty.

Just think how dissapointed you would be blowing the think end of £50k to find its really not all different to a 220/240.

I think the main problem is that to keep reliability they have drip fed the bhp increases making the differences between the old cup 255 for example and the latest cup 260 unnoticeable, had it jumped from 220 to 260 you might notice. I can remember having the ecu remapped on my BMW for an extra 35bhp and it transformed the car.

[Scuffers]

TOENHEEL said:

squirejo said:

I can tell you that my exige 240R is not noticeably faster in a straight line (on a circuit) than a Exige 220S and hence I would wonder whether a 260 would be any different until well into 6 figures, by which time the straight may be coming to an end. HP = straight line speed, torque and factors like grip = acceleration out of the bend.

Makes you wonder if blowing loads of money on tuning the 220 is worth it unless your going up to 280 maybe. I find my 220 is more than fast enough on the road, not a great deal keeps up unless its something else a little tasty.

Just think how dissapointed you would be blowing the think end of £50k to find its really not all different to a 220/240.

I think the main problem is that to keep reliability they have drip fed the bhp increases making the differences between the old cup 255 for example and the latest cup 260 unnoticeable, had it jumped from 220 to 260 you might notice. I can remember having the ecu remapped on my BMW for an extra 35bhp and it transformed the car.

Whist I get where you are coming from, there's more to it than that..

what you 'feel' when driving the car is not power, but torque, the only time power per say comes into it is how long you can feel the torque for (as in what point you have to change up cause it's fallen off the torque curve).

the 260 cup car should have noticeable better torque than the 220S, the problem comes with the 260 getting heatsoaked faster so the top of it's rev-range being blunted off much faster than the 220S.

At the end of the day, the engine can only make so much power for a given setup, the harder you run the supercharger, the more power it saps and the higher the temps will go, if you can't then get shot of that heat, then the ECU has no option but to back off the engine to avoid detonation etc, this will happen much more quickly on a 260 than a 220S as the heat loads are higher, and thus the det margin much smaller.

[TOENHEEL]

Scuffers said:

TOENHEEL said:

squirejo said:

I can tell you that my exige 240R is not noticeably faster in a straight line (on a circuit) than a Exige 220S and hence I would wonder whether a 260 would be any different until well into 6 figures, by which time the straight may be coming to an end. HP = straight line speed, torque and factors like grip = acceleration out of the bend.

Makes you wonder if blowing loads of money on tuning the 220 is worth it unless your going up to 280 maybe. I find my 220 is more than fast enough on the road, not a great deal keeps up unless its something else a little tasty.

Just think how dissapointed you would be blowing the think end of £50k to find its really not all different to a 220/240.

I think the main problem is that to keep reliability they have drip fed the bhp increases making the differences between the old cup 255 for example and the latest cup 260 unnoticeable, had it jumped from 220 to 260 you might notice. I can remember having the ecu remapped on my BMW for an extra 35bhp and it transformed the car.

Whist I get where you are coming from, there's more to it than that..

what you 'feel' when driving the car is not power, but torque, the only time power per say comes into it is how long you can feel the torque for (as in what point you have to change up cause it's fallen off the torque curve).

the 260 cup car should have noticeable better torque than the 220S, the problem comes with the 260 getting heatsoaked faster so the top of it's rev-range being blunted off much faster than the 220S.

At the end of the day, the engine can only make so much power for a given setup, the harder you run the supercharger, the more power it saps and the higher the temps will go, if you can't then get shot of that heat, then the ECU has no option but to back off the engine to avoid detonation etc, this will happen much more quickly on a 260 than a 220S as the heat loads are higher, and thus the det margin much smaller.

Spot on as usual

[JPF40]

Scuffers said:

I think the problem here is that these cars depend so much on the intercooler, and given some beans for more than a minute, it's so massively heat-soaked, as to be next to useless.

I can't see where you are getting the heats soak idea from, maybe whilst sitting in traffic, but at sustained speeds of over 70mph around a track? I think not, and I'm sure that's exactly what Lotus engineers would think too.

[TOENHEEL]

JPF40 said:

Scuffers said:

I think the problem here is that these cars depend so much on the intercooler, and given some beans for more than a minute, it's so massively heat-soaked, as to be next to useless.

I can't see where you are getting the heats soak idea from, maybe whilst sitting in traffic, but at sustained speeds of over 70mph around a track? I think not, and I'm sure that's exactly what Lotus engineers would think too.

I can notice a marked improvement in my car during the winter or on a cold day seems to have more get up and go.

[coxy79]

Is it a bad idea to put an intercooler on top of the engine?

I always thought it might be a bit of an interwarmer.

[The Pits]

Just what I was going to ask.

This heat soak issue would go some way to explain a friend's issue with his 240 exige. He find's it a bit 'moody'. by that he means some days it feels really fast, other days not quite fast enough.

Out of interest Scuffers do you think it's the placement of the intercooler that's the problem or the design?

Would a different intercooler fix this? And how do you get round the problem with the honda SC cars, surely they produce a good amount more heat?

[LivinLaVidaLotus]

Sat on top of the engine was never going to be ideal, hot air rises. Heat as we know travels from hot to cold areas - as it's right on top of the engine then it's going to soak away heat from the engine. ProAlloy do an IC that sits in the right hand side pod AFAIK.

[Phil-CH]

The location of the intercooler is a problem, not to mention it's being fed with air through a roof-scoop that wasn't intended in anyway for functional use and has now been modified in the latest cars by enlarging the scoop and bringing it to the front. This on the other hand increases CW and drag (which is why on the Nurbourgring/Nordschleife, it's not that much quicker on the straight as per the SportAuto review last late summer) despite the higher power output over even a NA Exige.

Because the intercooler is a problem, every decent company offering S/C kits for this car has gone with the more expensive route of adding a front mounted charge-cooler.

Per reference: My car (with charge-cooler) runs fine on hot summer days at 35°C (road temps higher) with engine oil being around 95°C and induction air (after chargecooler) no more than 45°C - 50°C. Sure, it runs better on cooler days, but the difference between outside temp and induction is always around 10°C - 15°C. No heatsoak issues either. For the record, these stats are max stats and while driven *very* hard for extensive time.

Edited by Phil-CH on Wednesday 1st April 11:53

[cyberface]

Well the Scooby had an intercooler mounted on top of the engine, and even though the engine was in the front, the big power cars needed to relocate the intercooler to the front. With the Lotus mid-engined design, that's a bit trickier and what you gain with a water-air chargecooler setup with extra heat exchangers at the front of the car, you presumably lose with the weight gain of the additional water circuit.

Whilst I'm interested in the Gotham chip + injectors package for 280 bhp, it's sounding suspiciously like this peak power would only be possible for a few acceleration runs before the standard intercooler saturates and IAT rises to the point where the ECU has to rack things back.

I like superchargers and have had various conversions on my cars - and Roots-type blowers are a particular problem when it comes to heating the intake air. Ideally I'd like a twin screw unit and a decent chargecooler setup on the Exige but nobody offers this. So I'm still in a bit of a quandary as to what to do

squirejo said:

hence I would wonder whether a 260 would be any different until well into 6 figures

6 figures? They're quick, but surely not *that* quick...

[bencollins]

Power extraction is only possible proportional to oxygen being put in, in combination to petrol, but the more you charge it the hotter the air gets and the lower the density of the initial charge and the more it needs to be cooled.
As i understand in the Elise it is less to do with location and more to do with cooling capacity, determined by:

a) size
b) flow
c) charging pressure
d) ambient temp
e) cooling medium.

(e) is the most important, liquid cooling is superor to air due to density.
The Lotus folks have decided air to air is sufficent fit for purpose. For racing air to liquid IC is necessary.

If you were building the "ultimate" OTT small capacity charged engine you would have intercooling, aftercooling and maybe even mid cooling and a cooled manifold. Then multiple direct and indirect injection fuel squirts to further lower the temps. And put the engine inside a phillips whirlpool freezer*

In my opinion there are two choices for improving cooling,
a)swap A2A for A2L ICer
b)rather than bin the air to air intercooler, a secondary cooler A2L might be useful, but where to put it?!

• AF

[TOENHEEL]

what about water spray? would this have much benefit?

Edited by TOENHEEL on Wednesday 1st April 12:35

[bencollins]

TOENHEEL said:

what about water spray? would this have much benefit?

Edited by TOENHEEL on Wednesday 1st April 12:35

Water Spray:
OK well im guessing but water spray system are on the EVOs and i assume they are for "emergency" cooling when everything was getting heat soaked. Then again rally stages are only a few minutes duration. I cant imagine water spray is a useful solution outwith rally stages.

Multiple Icing:
The application of multiple intercooling and liquid systems of course demands big costs, weight, pumping loss and attachment problems so the designer makes a decision. The lotus system A2A is no doubt light, simple, reliable, pumpless. i.e lots of good points matched for the fast road car / occasional track car purpose.

Fan Proposal:
I wonder about the size and application of fans to the existing system, particularly as the current location is in an eddy zone. If Porsche can cool Race 12 cylinder engine with a fan (which I cant get my head around you would think it would melt) then a proper fan set up might improve things and be the next logical step or mod to a SC Exige without going to the complication of chopping or binning stuff. Cost//hassle/power yield must be the highest with a fan (or?).

A Hybrid
It could be switchable in the cockpit and only used when pushing on. That is also technically then a hybrid system using excess alternator wasted power when revving for a useful power (and slight fuel economy) gain. So its green too
Take the window out and it will warm your neck too. Think ill enter that green tech competition now

All theoretical of course, looking forward to reading other comments.

Edited by bencollins on Wednesday 1st April 13:54

[Phil-CH]

cyberface said:

Well the Scooby had an intercooler mounted on top of the engine, and even though the engine was in the front, the big power cars needed to relocate the intercooler to the front. With the Lotus mid-engined design, that's a bit trickier and what you gain with a water-air chargecooler setup with extra heat exchangers at the front of the car, you presumably lose with the weight gain of the additional water circuit.

The airflow in the Scooby is a lot better than what you get in the Exige on top of the engine though. The entire front a Scooby/Evo is practically a large intake.

The gain in weight is minimal with the charge-cooler. I think it doesn't account for more than a few kgs. Besides, the weight is all low down and not like the Exige-S where the heavy intercooler is right on top...