Discussion
Rich,
After 1000 miles I took it back to V8 Developments and they adjusted the tappets (they did need doing).
After that it is as smooth as silk! No tappet noise to speak of - I would say it's running sweeter than new. It does idle a little higher than normal (at around 1,000 RPM) but it's a very constant idle and very easy to drive in slow traffic.
Without questions it's a combination of many factors - cam needs improved induction to get the benefit, improved induction needs more fueling, more fueling means re-chipping, re-chipping needs a rolling road or dyno...
...but I know many people have started with an ACT plenum and larger flared trumpets and have been thrilled with the results.
After 1000 miles I took it back to V8 Developments and they adjusted the tappets (they did need doing).
After that it is as smooth as silk! No tappet noise to speak of - I would say it's running sweeter than new. It does idle a little higher than normal (at around 1,000 RPM) but it's a very constant idle and very easy to drive in slow traffic.
Without questions it's a combination of many factors - cam needs improved induction to get the benefit, improved induction needs more fueling, more fueling means re-chipping, re-chipping needs a rolling road or dyno...
...but I know many people have started with an ACT plenum and larger flared trumpets and have been thrilled with the results.
Acknowledged Steve.
Compensation was applied, but realistically (verging on pessimistically) compared with the air temperature readings taken in the workshop. It was really too hot to get acurate readings, but admittedly the compensation could have taken it either way.
Without the hose in place we got better power figures but low torque, and the air was being taken straight off the engine bay rather than from the air being blown at the radiator. With the hose in place we got stonking torque, but power was slightly lower. The hose was bent almost double at one point with several 90 degree angles, and judging by the wires sticking through the plastic it was probably collapsing internally... not good.
Tim at ACT reckons on upto 6 BHP extra with the new hose. I'm also allowing for a bit more from a different airflow meter. Time will tell!
Compensation was applied, but realistically (verging on pessimistically) compared with the air temperature readings taken in the workshop. It was really too hot to get acurate readings, but admittedly the compensation could have taken it either way.
Without the hose in place we got better power figures but low torque, and the air was being taken straight off the engine bay rather than from the air being blown at the radiator. With the hose in place we got stonking torque, but power was slightly lower. The hose was bent almost double at one point with several 90 degree angles, and judging by the wires sticking through the plastic it was probably collapsing internally... not good.
Tim at ACT reckons on upto 6 BHP extra with the new hose. I'm also allowing for a bit more from a different airflow meter. Time will tell!
shpub said:
...
With the new air hose and a cooler day I should expect to see around 310 BHP and 340 Lb/Ft.
Might not as the figures are usually temperature compensated.
Generally that is the case, but am not convinced that the compensation is always accurate, typically we see better results on colder days ?
Marlon out of interest what was the road wheel figure, we had a 500 with the same upgrades as yours with 260 @ wheels.
Tim
Hi Tim,
Don't remember off hand. When we had the first RR session the car was running very lean (hence bigger injectors recommended by Mark) and was producing 284 BHP (flywheel) at 4,700 RPM, which equated to 234 at the wheels. Suspect it is currently around 240... 260 sounds impressive! Mark says it is unusual to get one above 230, even with the mods...
Don't remember off hand. When we had the first RR session the car was running very lean (hence bigger injectors recommended by Mark) and was producing 284 BHP (flywheel) at 4,700 RPM, which equated to 234 at the wheels. Suspect it is currently around 240... 260 sounds impressive! Mark says it is unusual to get one above 230, even with the mods...
Marlon said:Interestingly, Lotus claim that the Rover K series has a 3% tolerance.......
Jeremy,
The Rover V8 is actually a pretty consistent motor from what I'm told - you certainly wouldn't expect a 30% variation... and most 500's are within 10 BHP of each other as standard, assuming no flaws elsewhere in the system (i.e. new).
I've posted a quote from Nick Adams from the lotus owners bulliten board that is now defunct - Nick was(is) one of the development engineers on Lotus cars..
Nick Adams posted 29 January 2001 13:21
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Hi Rob, Hi Mark,
Thanks for your questions, I hope the following answers them fully. I don't know you or your level of knowledge so please excuse me if I start from first principles. The ultimate power output of any engine is a direct result of how much air the engine can ingest. For a given amount of air, there is a maximum power output, which can only be achieved by setting all factors such as ignition advance and air fuel ratio to the optimum. Because a mass produced engine is made up of many components, each with a range of tolerances, the precise amount of air ingested at any condition will vary from engine to engine and hence the optimum settings for spark and fuel will also vary. When we set up (or calibrate, in engineer speak) the engine management system we take this variation into account and apply settings which are the closest to optimum for the majority of engines, while staying clear of settings that could cause damage in the (rare) case of an engine with all the tolerances in the wrong direction. In general, the variation in power output between engines will be within a band smaller than + or - 3%. We do not need to take factors such as emissions into account at full throttle other than to avoid temepratures that would damage components such as the catalyst. We (Lotus) are therefore able to calibrate in general to within 2 % of the ultimate output of most engines. A mainstream manufacturer may set the cal. slightly further from optimim to reduce risks of warranty claims in, for example, territories where fuel quality cannot be guaranteed.
So, to get rather labouriously to the point, fitting a pre-programmed chip to a bespoke engine such as the 160 will offer very little in the way of a benefit, typically no more than 2% (3.2PS) and more usually nothing. Setting the calibration on a rolling road to suit your specific car will guarantee a gain in that it will remove the margin of safety we dial in, but this will still only be in the order of 2%. Tuners who claim more are either optimistic or are prepared to run your engine into the boundaries of detonation, which will lead to tears in the long run. In my opinion, based on 16 years of dyno tuning engines at Lotus, the most a re-chip will achieve on a normally aspirated engine will be 5%, with a significant risk of engine damage. No manufacturer is going to set the standard cal more than a few % from optimum, why would they want to do that?
So, more power from a Lotus 160. I assume you've fitted the track only airbox and catalyst. A low restriction air filter gave us 2PS on the dyno's here, and wasn't specified because the cost and risk outweighed the benefit. You may choose to fit one, your call. The biggest increase would come from re-setting the calibration to make use of 98 RON fuel, but bear in mind that it's getting harder to find and the 160 doesn't have a detonation sensor and running at full throttle on 95RON will then damage the engine. If you do go that route you should see about 5-8% (circa 8-10PS) as an absolute maximum. The head gasket will be exposed to greater loads and may fail, the big end bearings would also be pushed harder than we would recommend, you would have to carry the risk. Beyond that, there's not a lot you can do before the engine will get seriously fragile.
With regard to the standard car, the original Elise cal was about 3% from optimum, the new car with the Lotus controller is about 2%. That's all a chip can give you (unless the car has a turbo in which case a quick tweak to the boost curve can work wonders)
. Any more is usually sleight of hand when driving the dyno. I am now ready for a torrent of abuse from all the tuners out there who make a living from selling chips.....
Hope you got to the end without falling asleep, let me know if the level of detail is too great (or too small). Cheers, Nick
And further - here is your "legal" answer...
+ or - 5% is the maximum allowed under EEC conformity of production rules.
I new I'd seen the actual figure somewhere.
Again taken from the now defunct lotus life BBS.
Nick Adams posted 26 March 2001 12:01
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Hi Ian, what did the rolling road tell you you had before you put the bits'n bobs on? All standard production engines are legally required to run within limits known as "conformity of production". Under EEC legislation these limits are +/- 5% of the manufacturers declared maximum torque and power figures. We declare 118PS for the original S1 Elise, so if it produces more than 124PS we are building illegal cars. I can assure you we are not. Judging by the data someone else has posted elsewhere on this page about the rolling road you used I would say it is reading between 7 and 15% too high. Do you really believe ALL of the cars tested that day (except for one non-Lotus approved conversion) were amazingly good examples of the breed?
The standard air filter costs about 2PS on our dynos compared to no filter at all.
Cheers, Nick
Edited to sort out bolding
>> Edited by joust on Thursday 21st August 18:54
+ or - 5% is the maximum allowed under EEC conformity of production rules.
I new I'd seen the actual figure somewhere.
Again taken from the now defunct lotus life BBS.
Nick Adams posted 26 March 2001 12:01
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Hi Ian, what did the rolling road tell you you had before you put the bits'n bobs on? All standard production engines are legally required to run within limits known as "conformity of production". Under EEC legislation these limits are +/- 5% of the manufacturers declared maximum torque and power figures. We declare 118PS for the original S1 Elise, so if it produces more than 124PS we are building illegal cars. I can assure you we are not. Judging by the data someone else has posted elsewhere on this page about the rolling road you used I would say it is reading between 7 and 15% too high. Do you really believe ALL of the cars tested that day (except for one non-Lotus approved conversion) were amazingly good examples of the breed?
The standard air filter costs about 2PS on our dynos compared to no filter at all.
Cheers, Nick
Edited to sort out bolding
>> Edited by joust on Thursday 21st August 18:54
joust said:
James - what you been drinking? What on earth are you going on about old bean - you've lost me.
J
Rob Newman and David Baddiel, 'The Mary Whitehouse Experience', c. 10 years ago. Also had Stephen Punt and Hugh Dennis.
(sorry, back to thread).
260 cf 340 is far worse pro rata than 21" cf 25" telly. But we don't care!
simpo two said:Oh my god - forgotton all about that. Fab stuff!
Rob Newman and David Baddiel, 'The Mary Whitehouse Experience', c. 10 years ago. Also had Stephen Punt and Hugh Dennis.
simpo two said:You are trying hard to keep this going...
260 cf 340 is far worse pro rata than 21" cf 25" telly. But we don't care!
Everyone knows that the telly's actually are the size stated, it's computer VDU's that aren't.
Interestingly an EU investigation into both VDU sizes and hard disk capacities resulted in both of them being required to have the actual visible area and useable capacity quoted in all litrature.
Who says the EU doesn't look after the consumer
Mind you, don't get me started on hard disks, since when has a Gbyte been 1,000,000 bytes??? It's 1,048,576 bytes and they should all be shot!
J
joust said:
simpo two said:
Rob Newman and David Baddiel, 'The Mary Whitehouse Experience', c. 10 years ago. Also had Stephen Punt and Hugh Dennis.
Oh my god - forgotton all about that. Fab stuff!
simpo two said:
260 cf 340 is far worse pro rata than 21" cf 25" telly. But we don't care!
You are trying hard to keep this going...
Everyone knows that the telly's actually are the size stated, it's computer VDU's that aren't.
Interestingly an EU investigation into both VDU sizes and hard disk capacities resulted in both of them being required to have the actual visible area and useable capacity quoted in all litrature.
Who says the EU doesn't look after the consumer
Mind you, don't get me started on hard disks, since when has a Gbyte been 1,000,000 bytes??? It's 1,048,576 bytes and they should all be shot!
J
One gigabyte equals 1,073,741,824 bytes m8
Edited to say - Shall I bring the gun then?
>> Edited by KeithS on Friday 22 August 16:52
joust said:
One gigabyte equals 1,073,741,824 bytes m8
Oh poo - you are quite right
KeithS said:
Edited to say - Shall I bring the gun then?
ep - I think you need to. Let's say 5:30 - my office?
Thank you for pointing out my inability to cube 1024
Sorry, I know no-one likes a smart arse! I have to admit that I did check it 3 times in case I made a prat of myself while correcting you!
KeithS said:
Sorry, I know no-one likes a smart arse! I have to admit that I did check it 3 times in case I made a prat of myself while correcting you!
Thanks anyway! (of course what I should have written was since when has a Gbyte been 1,000,000 Kbytes??? It's 1,048,576 Kbytes and they should all be shot!
) J
>> Edited by joust on Friday 22 August 18:45
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