miegru
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| posted on 12/1/07 at 09:08 PM |
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Rolling roads and ecu: chicken or egg?
A query some days ago regarding kms-ecu turned into some remarks about rolling roads.
Please bear with me; long story but a question in the end.
With my first seven (first DTA ecu, later OMEX) i visited 4 rolling roads in the Netherlands. I was completely new to this at that time but soon got
amazed at the different approaches. Also the quoted power and torque figures were all over the place. My 2.0l zetec with only throttle bodies as a
modification was making 203bhp according to one rolling road! Took it the next day to another one since it felt like 5bhp on the road.
I ended up with Kronenburg; the guy there seemed to know what he was doing plus he was actually showing a lot of respect for the car (taking care of
the paint, heating up the engine properly but also making sure the gearbox and diff had some heat before going for the full runs. After the session he
quoted by far the lowest figures ever (142bhp) but the car ran perfect. It felt twice as fast as ever before and super smooth.
For my current car I chose KMS mainly because I knew that the guy at KMS (Stefan) will get the best out of it. How does that go with others?
In the uk I hear good things about Dave Walker's rolling road and Emerald.Is Emerald so good because of Dave W mapping them or is it really
better than others from an electronics perspective?
What are the rolling roads to use in the UK and what are the ones to stay away from?
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damien
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| posted on 13/1/07 at 08:50 AM |
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dave is a very good mapper not just with emerald, i dont know if he does kms tho
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chriscook
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| posted on 13/1/07 at 10:28 AM |
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You will get different results from different rolling roads as they are unlikely to be properly calibrated on a regular basis. Also it may be that the
first place was quoting a power at the flywheel and the second at the wheels. The corrections for rolling loses may also be handled differently at
different places.
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stevebubs
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| posted on 13/1/07 at 11:14 AM |
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quote:
Originally posted by miegru
In the uk I hear good things about Dave Walker's rolling road and Emerald.Is Emerald so good because of Dave W mapping them or is it really
better than others from an electronics perspective?
Dave Walker has an excellent reputation for tuning so gets a lot of press.
Emerald is popular over here because it's a plug-conversion for the K-Series ECU as used in Cateringvans and Elises. Having said that, the
Emerald interface is very slick and easy to use. It provides beginners with a much easier entry point than, for example, Megasquirt.
(edited to improve grammar)
[Edited on 13/1/07 by stevebubs]
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chockymonster
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| posted on 13/1/07 at 12:12 PM |
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You see these sorts of discussions on power all the time on car forums. On the Lancerregister there was a "forum" dyno. any power figures
that wanted to be compared were taken at this dyno, a Dynodynamics in shootout mode. Also wheel figures where never given as the calculations varied
so much!
The only way you can ever tell how much bhp an engine is producing is to take it out and bench test it. Rolling roads will give you an idea to work
from then.
PLEASE NOTE - Responses on Forum Threads may contain Sarcasm and may not be suitable for the hard of Thinking.
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blueshift
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| posted on 14/1/07 at 11:24 PM |
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People use a variety of methods to correct wheel bhp to flywheel bhp on a dyno, and it may correct artificially for temperature etc as well.
In my experience the only things a dyno is really good for is showing you the shape of your torque curve, and showing you the power difference before
and after: if you run the car on the same dyno, the same day, with the engine, tyres and air at the same temperatures.. etc etc.. if you take it off
and put it back on, how hard you strap it down can have an effect too.
They are only good for giving a ballpark idea at best of flywheel power.
Also there is some degree of "marketing" going on. If these people are tuning your car and showing you nice high power figures on a pretty
graph, they might make more money than the guys down the road who read 5bhp lower on every car. There are ways to make a dyno read higher power than
the car is capable of.
I work at a tuning company by the way, we have our own dyno.
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NS Dev
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| posted on 16/1/07 at 10:47 AM |
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will echo the posts above.
Dave Walker, despite selling in direct competition, i think would bethe first to praise DTA as well, the DTA ecu is NOTHING to do with any power
losses.
Both Emerald and DTA are known for their free and very user friendly software. in fact the man behind DTA is first and foremost a racer and engineer,
with the elecronics coming in to complement that.
Both companies know what they are doing and both systems are at the mercy of rolling road operators.
if its the same in the Netherlands as here then they vary HUGELY in standard!!!
50hp variation from one to another is not at all uncommon.
What you need is an operator who can set the engine up correctly.......what power it makes is down to who specced and put together the engine, so
unless you plan on pulling it apart again it matters not one jot what power it makes as long as the fuelling and ignition are correct.
To that end, find a rolling road that uses an electronic microphone on the block of the engine to listen for detonation, and also steer well clear of
ones who give a fixed quote to map the engine. They can't do this, as they will not know how long the job will take. They should quote a
"per hour" figure and then an estimate of the hours, but nothing more.
I would always budget for a full day just in case, which will be between £300 and £400 at most sensible places in the UK
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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