Acceleration stats?

General General Lotus Talk
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Just wondering if anyone has managed to accurately record their Exige�s performance from 0-60mph. I tried it a few times last night using the ap22 http://race-technology.com/WebPage/Products/Accelerometer/ap22/Ap22Introduction.htm and was a bit disappointed. I know the Exige is not all about shooting off at high speed, but I expected it to be a bit better than my old Elise. The best I could record is 5.7 seconds to 60.My technique was to get it to about 3.5 - 4K rpm drop the clutch, then change to second gear about 6.5 - 7k revs. I�m not really to keen on blatting in any harder. Does anyone know the proper way � i.e. how do Lotus gets their stats ?

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As has been said a few times before, it’s not overly easy to get a good get away in an Exige and it knackers the clutch (and everything else). So I won’t be giving it too many goes but I’ll try and have a bash this weekend.Personally, I think you need a few more revs to start with, although not too many as the clutch just spins/bounces. Unless your car isn’t run-in, I think you need to ring out every last rev, all the power is at the top end.What settings are you using on your AP22? That’s important for its accuracy. I’ll try and double check mine and perhaps taking an average of everybody that has calc’ed them for an Exige is a good idea.Ian [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]

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I’m using the default settings - I will try and dump the performance data to my PC over the weekend and post it on this thread.

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Nick Adams on the lotuslife BBS explained the technique a while ago, from what i remember (and thats not a lot these days !) rev to 6K, slip the clutch until 4-4.5K and change gear at 7.5KPhil

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Well I tried Nick’s method a couple of times but haven’t perfected the clutch slipping part and was hence rather poor. I certainly would’nt win any sprints!If you plot the results (below) you can kinda see the velocity doesn’t really start climbing well until after 40mph. I was surprised the results were as close to 6 secs as they were (completely std engine), because the revs just died (as per normal) when I started. The 0-60 in this car means nothing really.For those with AP units, I calculated the figures for calibration as:Time1 (decelerate from 60mph to 55mph) = 4secsTime2 (decel from 15mph to 10mph) = 11secsMass (with me) = 870kgs thereforeCdA = 0.82Rolling Resistance = 0.019I left the other Tilt (0.011), Roll (0.011) & Smoothing (0.004) as I’d have them for my Scooby.Having said that, the results below were actually taken with a CdA of 0.9 and a Rolling Res of 0.02, as I forgot to take a calc with me and the sums are a little big for my head to be too accurate!It’s difficult to find a quiet, completely flat area to do the tests on and each time I tried the results varied quite a lot. I discarded some of the more wild measurements before taking an average. If anybody knows the more scientific CdA and Roll R that’d be great. Anyway, here are the results…Start Speed 0.0mph mph s g ft hp 10.0 0.61 0.78 4 41 20.0 1.49 0.47 24 50 30.0 2.44 0.49 59 80 40.0 3.40 0.49 108 108 50.0 4.87 0.31 204 93 60.0 6.40 0.27 328 104Pk Power: 44.0mph 4.01s 145ft 120hp Peak G: 13.3mph 0.78s 7ft 0.82g----------------------------------------Start Speed 0.0mph mph s g ft hp 10.0 0.70 0.87 4 45 20.0 1.55 0.44 23 47 30.0 2.47 0.50 57 81 40.0 3.42 0.49 106 108 50.0 4.75 0.33 194 98 60.0 6.28 0.27 318 104Pk Power: 47.0mph 4.31s 163ft 130hp Peak G: 13.4mph 0.86s 6ft 0.91g----------------------------------------I’ll try and get some more in depth data (inc. std brakes) shortly.Ian [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]ps. If you are the chap who left the Ely meet (in Hampshire) last year with wheel-spin, please identify yourself and let me know the technique.

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When I recorded 0-60 I had the following settings (which are not the default) � I borrowed this unit from someone with a 190 Elise and assumed my set up should be the same.CdA at 0.420,Roll resistance at 0.013,Tilt fator at 0.007,Roll factor at 0.011 and Smoothing 0.004I did two tests one in each direction on the same piece of roadStart Speed 0.0mph mph s g ft hp 10.0 0.88 0.60 5 30 20.0 1.52 0.76 19 76 30.0 2.25 0.56 47 85 40.0 3.42 0.25 109 53 50.0 4.62 0.36 188 95 60.0 5.89 0.36 291 117 Pk Power: 60.0mph 5.89s 291ft 117hp Peak G: 22.8mph 1.67s 24ft 0.80g ---------------------------------------- Start Speed 0.0mph mph s g ft hp 10.0 0.80 0.67 5 33 20.0 1.43 0.60 19 59 30.0 2.23 0.57 48 85 40.0 3.36 0.31 108 64 50.0 4.52 0.36 185 95 60.0 5.78 0.35 287 112Pk Power: 59.1mph 5.66s 276ft 116hp Peak G: 18.4mph 1.28s 15ft 0.80gNot sure what are the correct settings are for the Exige and the AP22I would love to get the 0 � 100mph but I�m waiting till I get on suitable terrain.Re: ps. If you are the chap who left the Ely meet (in Hampshire) last year with wheel-spin, please identify yourself and let me know the technique.I though not being able spin them wheels was a good thing ! Needless to say twas not me.

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quote: Nick Adams on the lotuslife BBS explained the technique a while ago, from what i remember (and thats not a lot these days !) rev to 6K, slip the clutch until 4-4.5K and change gear at 7.5K I will give it a bash and let you know if the timing improves - THANX

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quote:Originally posted by leon:Pk Power: 60.0mph 5.89s 291ft 117hpPeak G: 22.8mph 1.67s 24ft 0.80g Pk Power: 59.1mph 5.66s 276ft 116hpPeak G: 18.4mph 1.28s 15ft 0.80gHmm?I’d question your settings a little, as with a peak hp of only 117bhp (albeit at the wheel), you’re achieving a lower time. Although the lower hp could be down to you not using the revs as much. Is yours a 190?Your peak hp comes as you ringing it out in 2nd rather than mine in 1st. I think you may have backed off slightly just before 60mph on the second run as the peak was at 59.1.If you can get the wheels to spin briefly the revs don’t die as badly and the load on the transmission reduces. Grip from spinning wheels comes back quicker than revs do. It’s the technique used by car mags to get their best times. It’s possible an Exige may even get a slightly better time on damp tarmac where the wheels can spin (it was dry at the Ely, so that wasn’t the cause there).Ian [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]

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I was not really looking at the hp reading � I do not recall what I set the weight to � think it was about 800kg � which is probably to light. Thinking that the Exige is meant to be 785kg + me at about 90 kg should have a setting at more like 875 � which may give more sensible hp readings.My Exige is the 190, with oval sports exhausts, new tyres, all running very well (as far as I can tell). My synchromesh is getting a bit worn � i.e. it grates a little when changing (even during normal driving) - so I will probably try again once its been sorted. �Leon

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Anyone have some new/better numbers to give me?? If not I’m using IDG’s numbers.
(just received the Ax22 with live lap times on display )

Cda : 0.82
Roll Resistance : 0,019
Tilt Factor : 0.011
Roll Factor : 0.011
Smoothing : 0.004

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Yep, I reckon those stats are about right. Pretty much the same as I got on an ap22 and a DL1 data logger for a standard exige 190. They are a pig to get off the line quickly and I frankly don’t believe lotus’s figures at all.To get decent power fig’s you need to run the car up to 100mph plus then you should see around 150-160hp at the wheels if you’ve set it up right!

Also my 0-100 time was at best around 14 secs. Tried the same exercise with my Noble and can get 0-60 in under 4 secs without much trouble

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I recorded a 0-60 time at the Bruntingthorpe sprint circuit last weekend of 4.8 and the clutch gave up. I definitely could have gone faster and was dissapointed with the results especially as my mini did a 3.5 dead the week before on my ratty set of tyres. (however my mini is very quick off the line !! )

I was using AO49 Yoko’s tyres @ 20psi and still a lot of wheel spin followed by clutch spin !

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I know Lotus have little mechanical concern when setting these times (clearly like Pegbox!).

I do find it funny though that Lotus claim 4secs for the Exige S and a 800kg (i.e. 25% lighter) S1 with 230bhp can only do 4.8.

Is the Yoko A049 a new tyre Pegbox?

Ian

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I think if you want a “proper” sprint car you need one of these -

goto ebay and search for this number 4645658626

I think he might have got carried away with the performance claims. That 0-140 time is 2.5 seconds quicker than my GSXR1000 - RETAR*D