jeffw
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| posted on 25/9/10 at 04:36 PM |
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Rolling Road again
Back to ATspeed this morning to get the final bits done to the map on the Omex and play with the cam timing.
State of play from the last session was 122 lb ft & 150 BHP at the wheels. I have since discovered that the throttle wasn't open completely
when the pedal was on the stop....since corrected that.
So we played with the inlet timing, added some more fueling and then played with the exhaust cam. Final figures where....
146 lb ft & 165.2 BHP at the wheels (20% losses gives 206.5BHP & 182.5 lb ft). The car has gained over 20 lb ft all the way from 3000 to 6500
rpm. It is a complete missile now in comparison, I'm amazed the difference a few hours on the rollers has made. Still not the figures that where
promised the supplier of the cams and heads but it is a really quick car now. Very pleased, we even had time to fit the new geared Hi-Torque starter
motor. I now have to watch how much throttle I put on coming out of 2 & 3rd gear corners otherwise the R888s start to get a bit sidewise.
Given that I had 140 BHP when I bought the car it has come a long way  Looks like the exhaust headers is holding back the peak HP figure a little
but even so very pleased.
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adithorp
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| posted on 25/9/10 at 05:29 PM |
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That sounds superb. I guess I'll have to push the braking points to the max now!
adrian
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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jeffw
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| posted on 25/9/10 at 05:39 PM |
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It's pretty quick now Adrian....might even get close to your BEC 
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MakeEverything
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| posted on 25/9/10 at 06:13 PM |
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quote:
Originally posted by jeffw
I have since discovered that the throttle wasn't open completely when the pedal was on the stop....
Dont you need to calibrate your TPS with Omex then? If this was MS, then it would have been apparent on first start.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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jeffw
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| posted on 25/9/10 at 06:16 PM |
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I think you miss-understand. The pedal was hitting the stop before the ITBs where fully open so there was a little bit of throttle left. The car
used to run MS with the same throttle setup ...don't see why you would see it in MS or Omex as the throttle didn't go to the max.
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britishtrident
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| posted on 25/9/10 at 09:53 PM |
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quote:
Originally posted by jeffw
I think you miss-understand. The pedal was hitting the stop before the ITBs where fully open so there was a little bit of throttle left. The car
used to run MS with the same throttle setup ...don't see why you would see it in MS or Omex as the throttle didn't go to the max.
There should always be a little bit of throttle butterfly motion left when the pedal is pressed hard against the stop. The tiny bit of of lost motion
is essential iIt is required to stop the carb spindles getting bent or the throttle cable breaking.
[Edited on 25/9/10 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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ashg
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| posted on 25/9/10 at 11:03 PM |
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the thing i love about Atspeed is that there are no bullsh*t bhp figures to flatter your ego.
they will tune it for everything it can do and what ever they say it is, is really what it is.
manufacturers of heads cams etc will always claim silly gains because it sells.
atspeed have nothing to gain and their policy of if its not better to drive at the end of the day on the rollers its free tells you everything to need
to know about their approach to tuning engines.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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jeffw
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| posted on 26/9/10 at 06:12 AM |
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Have to agree regarding ATspeed. Great guys and, as you say, it is what it is. Having said that they where surprised with the improvements we made
yesterday moving the cams around especially in the mid-range.
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franky
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| posted on 26/9/10 at 08:28 AM |
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great results, what cams/headwork have you had done? does the engine make smooth power or is it a little 'cammy'?
You must be over the moon
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ashg
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| posted on 26/9/10 at 08:17 PM |
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i can guarantee that it will be very well delivered throughout the range if they approached the setup anything like they did on my car.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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jeffw
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| posted on 26/9/10 at 09:14 PM |
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The car has a brand new blacktop Zetec with a "CNC Heads" port/polished/large valve head and their cams (which are somewhere between fast
road and Rally cams). The claim was that the engine would make 235-245BHP but we have not been able to make those figures.
The car is quiet smooth but pulls like a turboed car from 3000rpm when the cams come in. 183 lb ft is a lot for a NA Zetec and certainly the engine
feels very strong.
To get the extra HP that the original vendor claims it would make would almost certainly require pocket pistons and different (higher lift) cams.
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adithorp
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| posted on 27/9/10 at 03:35 PM |
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quote:
Originally posted by jeffw
To get the extra HP that the original vendor claims it would make would almost certainly require pocket pistons and different (higher lift) cams.
...or a recalibration of the RR You can always make a few extra horses that way.
You did remember to add 25bhp to the figures before posting, didn't you?
At the end of the day it's not a matter of how high the numbers are. Just that you've got the most you can from the set up you've
got and the way it's delivered.
adrian
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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MikeR
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| posted on 27/9/10 at 03:48 PM |
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why did you move from megasquirt (and which one did you have?)
What have you gained by going omex?
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jeffw
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| posted on 27/9/10 at 05:13 PM |
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I had a Megasquirt MS1 V3. The reason was pretty simple. I wanted a commercial product which did what I wanted without having to solder bits on the
board and was supported by tuners generally. I went with Omex as that was what ATspeed use and recommend. The car seems much smoother with the Omex
and I have a greater confidence with the whole setup (had the loom fitted at the same time).
I'm sure you could do the same thing with a Megasquirt but I'm also sure it would take a lot longer and not be quite as good. At the end
of the day I wanted a quick car without having to learn the complexities of ECU tuning to do it.
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jeffw
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| posted on 27/9/10 at 05:18 PM |
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quote:
...or a recalibration of the RR You can always make a few extra horses that way.
You did remember to add 25bhp to the figures before posting, didn't you?
So very true....the figures are the ones from the Dyno though so maybe I should do Pub figures and real figures (Pub Horse Power PHP) lol.
I've seen a number of Zetec engined cars claiming 190BHP with just ITBs and 210BHP with ITBs & Cams. Given what I've gone through I
treat all of these claims with a pince of salt.
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