ECU

The Oily Bits S1 Specific Topics
1

Chaps,This is relevant to you lot as the Exige is a victim of poor lotus engine mapping at low revs also…I have a S160 which is basically crap at low revs, It idles agresively between 1100-1400rpm and Anyway after advice from a number of members on the Elise BBS I decided to do a number of things - Change the exhaust manifold, fit throttle bodies and a new ECU.The difference is frankly amazing, It now idles at My advice if you are using your exige’s as a road car at all would be to switch the ECU on your VHPD’s to something like an Emerald or DTA - And use one of the maps that have already been devloped so you’ll have no need to spend on that either. So if your looking at a 190 upgrade, try doing it without the ECU bit and get a different one! No doubt it’ll screw the warranty but the difference is marked…I’m not trying to sell you anything just really impressed with the Emerald I’ve fitted and the results to the overall enjoyment of the car that a proper mapping for the engine can give.Still trying to hold off buying an Exige, and the job i’ve done on the car has helped alot but that Laser blue Exige in Peter Smiths is still calling me…Rich

2

RichThanks for the info. as I am considering fitting an Emerald chip aswell after hearing good things about them.Your S160 sounds as if it use to run pretty similar to an Exige: )Are there no drawbacks to this chip and is cold starting still OK?Thanks - AlP.S. Hurry up and get an Exige - u know it makes sense. [image]http://www.exiges.com/ubb/NonCGI/images/icons/blush.gif[/image]))

3

GuysHave been looking into this myself as I am not enthralled with the reports of the Lotus ecu. There is a good write up at :-AOL.co.uk | Breaking News, Sport, Features and Video - AOL.com

4

Well, At the mo its reasonably hot so it starts as normal. I haven’t re-fitted the IACV as I couldn’t be arsed with all the plumbing.When its cold I’ll have to start with the throttle for a couple of secs but apparently its reasonably good.Fortunately the Exige has the IACV ready an waiting so it’ll start just fine hot or cold.Why the mapping on the Lotus ECU’s is so poor is beyond my comprehension after trying mine with the Emerald unit. Still can’t believe it ticks over smoothly at 900rpm - before it was 1200-1400 an lumpy as hell.Seen no drawbacks yet! other than that bloody laser blue exige [image]http://www.exiges.com/ubb/NonCGI/images/icons/wink.gif[/image]

5

First off can you tell me where you had the work on your S160 done? and when you talk of the crappy ‘190’ ECU do you mean the MEMS unit or the later EFI technology unit? i have an S160 with the EFI unit and inhave been told the only reason the idle is so high is to clear the gas test due to the cam overlap, is your car o.k for the test?D.

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Dean, you are quite right about the elevated idle speed it is to keep the cat lit for the mot and European emissions test. The 190 ecu is an EFI unit as used on the Esprit v8, Exige and 340R. The Sport 160 ECU is either a GEMS unit (First batch of cars) or an EFI unit. Despite what some people will tell you the EFI ecu is in fact a very good unit that was originally developed for motorsport applications. The mapping for the sport 160 has been critisised as being crap but this is not strictly true. The car as it leaves the factory must be capable of passing a full European emissions drive cycle test, cold start to -20 deg C, run ok at altitude and pass European drive by noise regs. None of the after market controllers you buy will have had this much work done to map them. In the case of the sport 160 it is the base engine spec which causes most of the problems and not the mapping. Most of the improvement Rich B got was not from the ecu but from the multi throttle setup which works wonders on this engine as the original plenum causes problems when combined with the cams that are used. If you want to know more about this engine or any other aspects regarding the sport 160 drop email me off line and I’ll fill you in.

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Sorry Pablo,Thanks for the message about the 160.I cannot fidn your email address, i think you left it off your login info?I have done some more looking around i am looking to push the power up to 180-190 brakeI was considerign some QED throttle bodies, a pair of 285 piper cams (Timed in on verniers) and changing the ECU, so would i be better going for an emerald item? or just upgrading to the 190 EFI unit (My car is not one of the first 50)What do you think? would the standard 160 ECU struggle to fuel the throttle bodies, and run the engine way too lean?RegardsD.

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Dean,I’ve done a lot of work with this engine and you have a couple of options. The most reliable and cheapest option is to replace the original throttle body with a trophy 160 one, fit a vernier pulley to the inlet cam, (I can supply the figure you need to time it to) and then alter the mapping in the original controller,( I can do this for you). This will give you slightly more power and vastly improved drivability without stressing the engine any more than it already is. The second option is to fit a good quality set of throttle bodies which will improve drivability further but need to be carefully sized for the 160 engine. The last thing you want to do is throw anymore cam at it as the originals are far too aggressive as standard.The main problem you will have which ever route you take is that the engine in the 160 is only safe to 7000rpm. To make full use of the piper cams you need to rev to 7500rpm which means forged pistons, have the head ported and fitted with the bigger VVC sized and valves. Also the injectors become marginal at this level and are on there limit.You can certainly fit an Emerald unit to your car and it has some advantages such as mapping access etc but there are people around who can re-map your ecu or you can buy the communication tool and have a go yourself! If it was me I would just change the cam pulley and throttle body and leave it like that.Try the email again

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Pablo,I’d be grateful if you could drop me a line please.

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Dean,I’m running a S135 head (same as your S160 head) with Piper 740’s (BP285M), QED CTH TB’s and an Emerald. The BP285H are pretty equivalent cams, bit less lift and duration.All I can say is it goes pretty well, probably about 170bhp (was 161bhp at the SELOC RR and the exhaust timing was miles out! now remedied by DVA) idles rock solid at 850rpm and very driveable. Fuel economy isn’t too bad either (ie better than a standard S160!).Have a look at DVAPower website (AOL.co.uk | Breaking News, Sport, Features and Video - AOL.com), which is Dave Andrews tuning co.If you want to go any further than this, then the head is going to need porting properly with big valves (�600 ish exchange?) and then you’re looking 200+CheersChris