Performances of Elan Sprint 1972 versus Elise S1 1996

[bs982367]

I am the happy owner of an S4SE equipped with big valve head (so like the Sprint) but I cannot accelerate like the Elise S1 - 120 HP and 740 kgs.
Indeed, as you can notice on the road tests, we have the following figures:
0-60 mph: 6.5 sec Elan Sprint ( Elise S1: 5.8 sec )
0-100 mph: 19 sec Elan Sprint ( Elise S1: 17.5 sec )
The Sprint has even a slightly better power/weight ratio, so how can we explain such a difference ?
The gearbox and differential ratio cannot play any role here because we do not exceed 160 km/h.
Thank you !

[GrUmPyBoDgEr]

The difference lies most likely in the Torque figures for both engines.
The 1,8 Liter engine of the Elise must have more than the 1,6 Liter Twincam,

Cheers
John

[rcraven]

You're assuming that the road test times and the manufacturer's power figures are all accurate and reproducible in normal cars and I wouldn't assume any of that.
PS, following on from what John said, the torque at 3000 rpm of the Elise engine is said to be 122 lb ft and the Sprint at 5500 is said to be 113 lb ft.

[Bruce Crowthorne]

Like you I have both an Elan (S4 105bhp) and an Elise (S1 - about 150bhp).
And yes the Elise is MUCH quicker.
My guess is that Lotus would have been getting away with murder in the Elan road tests - probably supplied "special" cars for the road test!

I treat my two cars totally differently. In reality the Elan is for nice days and gentle drives (well compared to most road users) whereas the Elise is for fast drives and the odd track day.

IMHO the biggest difference is in the handling and levels of grip. The Elan can be drifted quite happily at legal (ish) speeds on the road (predicatble handling, gently approaches it's limit of grip, but has only moderate levels of ultimate grip).
The Elise has so much grip that it corners much more quickly that any Elan and the level of grip is such that you can only really explore it's limits of grip on a track or airfield. When it finally let's go it is predictable, but it reaches it's limit quite quickly and I am not a good enough driver to drift it (I have tried - but failed!)

Just enjoy them both! And appreciate how lucky we are to won the best two Lotus road cars ever

Bruce

[bcmc33]

I think John and Robert are correct as far as they went.

An standard average big-valve Twink will produce 110 bhp and 100 lb.ft of torque. The published figures were always enthusiastically optomistic ? typical of Lotus at the time.

In today?s environment the figures quoted by OEMs are more believeable because of legality issues that did not exist in the 60?s.

[GrUmPyBoDgEr]

Road test & Press Cars are were & always will be "special"
Today they are put together & checked that they meet the "published" figures, back then well who knows what lengths manufacturers went to.
It's well documented that Lotus Cars were "Doctored" when the Guv'ner wanted a drive so no doubt about the test Cars in my mind.

I know of one German Car maker that put 2 Cylinder Head Gaskets in their Engines to keep the performance down for the official testing.


Cheers
John

PS I'm pleased to say that my S4 Elan will give an Elise a run for it's Money

[gjz30075]

PS I'm pleased to say that my S4 Elan will give an Elise a run for it's Money

Me too, John. All the more reason to build a stroker motor these days. Mine puts out (dyno'd at the flywheel) 150 hp and 138 lb/ft of torque. Idles like a stocker, too. Bring 'em on.

Greg Z

[bcmc33]

PS I'm pleased to say that my S4 Elan will give an Elise a run for it's Money

Me too, John. All the more reason to build a stroker motor these days. Mine puts out (dyno'd at the flywheel) 150 hp and 138 lb/ft of torque. Idles like a stocker, too. Bring 'em on.
Greg Z

The QED cams I have for my new ported head should make a difference. The QED dyno results showed 148 BHP & 132 lb.ft of torque running on Dellorto 40's. I have injection so expect to get a little more. I plan to get the rolling road set-up to concentrate on torque and not power - if that's possible.

The object???? To beat the Elises down the straights at sprints and track days.

(No, not really)

[bs982367]

Bruce

Thanks for the valuable comments. You said:

Like you I have both an Elan (S4 105bhp) and an Elise (S1 - about 150bhp).
And yes the Elise is MUCH quicker

I suppose that you have the S1 111S which is definitively much quicker than my S4 (Sprint specs) and my S1 standard.

I also agree with your comments and the Elise is much quicker , and not only in acceleration !

[Bruce Crowthorne]

Actually mine started as a 118bhp car, but as with most Lotus I have swapped the cams (270s), exhaust manifold and back box and mildly ported the head (a la Dave Andrews) but run the stock ECU. So that should be about 150bhp.

150bhp in an Elan should be "interesting". I assume that is when you need as wide rims and tyres as you can fit plus the solid driveshafts to get rid of the doughnuts?

Love to have a shot in one if anyone is at a trackday at Goodwood (5 minutes from my place)
Bruce

[MintSprint]

For what it is worth, Evo magazine took a full, accurate set of performance figures for their editor's Elan Sprint as part of a group test against the Smart Roadster, MX5 and MR2, and achieved a much better 0-100 time than anything I've seen in period road tests (16.3 seconds). The 0-60 time was 6.8 seconds on this test, incidentally.

I suspect (though they didn't mention it) that this car may have been running a QED 420 spec engine or something similar, though.

The Elise (even in basic 118bhp form) has a little more torque than the Elan Sprint, though my experience of the Elan is that the 8-valve Twin Cam actually feels a lot gutsier and torquey than the K-series (though my car is modified to similar to QED 420 spec., too).

My own feeling is that the other big contributing factor (particularly for the 'dissapointing' 0-60 time) is old fashioned carburettors versus modern engine management: when you're trying to juggle limited grip against power and revs for a clean take-off on fragile rubber driveshaft couplings, the precision of modern fuel and ignition management would make a big difference.

[bcmc33]

The new head I have for my car is an unused 3 year old QED 420 version with maximum size inlet and exhaust valves.

The car is booked in for rolling road set-up first week March - I will report the results.

However, the 0-60 & 0-100 times will not be exactly independent.

[dlbutler]

My Elan with a stock Big Valve Stromberg that was tuned to the max was fast, but modern cars could keep-up and some could even out run it on the long staights, but not the corners. So, I rebuilt it with a FFI (Formula Ford 1600cc) crankshaft and special pistons to match (1700cc now), reground camshafts (Dave Bean #112). Almost every part in the engine has been modified. Now I keep-up with the supercharged Elises and, last time out, a Ferrari 308. It's a bit tempermental, but much faster and a lot more fun! Now the acceleration is in keeping with the handling. I'm glad I made the changes.

Don

[richgilb]

And are you sure you are as competent at getting your car from 0-60 as test drivers were / are?

[rgh0]

Keeping up with Elises of all types in my Elan is relatively easy but it helps if you have around 170 hp and a well set up suspension on sticky tyres. A well driven Elise that has good tyres will still be hard to beat in the corners but you can take them down the straights

cheers
Rohan