rolling road figures

Talk about the E-Type Series 1
User avatar

abowie
Posts: 2359
Joined: Wed Sep 07, 2011 9:15 pm
Location: Australia
Contact:
Australia

#21 Re: rolling road figures

Post by abowie » Mon Jul 01, 2019 11:57 pm

Heuer wrote:
Mon Jul 01, 2019 2:00 am
Engine was built in 1999 by VSE to their VSE02 fast road spec:
On the receipt I see that they drilled 1/8" holes in the butterflies to prevent stalling. Do you know their rationale for this rather than just using the slow idle screws?
Andrew.
881824, 1E21538. 889457..oops
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Heuer
Administrator
Posts: 12717
Joined: Sat Mar 01, 2008 5:29 pm
Location: Nottinghamshire
Great Britain

#22 Re: rolling road figures

Post by Heuer » Tue Jul 02, 2019 9:16 am

The cams cause very uneven idle so it was done to prevent stalling when waiting at traffic lights. Another consequence of the search for power.

Fortunately the EDIS/Megajolt now keeps the idle rock steady at 750 rpm.
David Jones
S1 OTS OSB; S1 FHC ODB

Add your E-Type to our World Map: viewtopic.php?f=1&t=1810

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

WebconUK
Posts: 14
Joined: Tue Nov 17, 2015 10:51 am
Location: Sunbury UK
Great Britain

#23 Re: rolling road figures

Post by WebconUK » Tue Jul 02, 2019 10:55 am

A few years back, when we were still in the ECU business and had our own rolling road, we did some back to back testing on a standard 4.2 Etype , mainly to see how a well mapped ignition system affected the torque, but it also shows a stock SU equipped power curve alongside the same engine fitted with Webers, and below are the results we saw
Image

Link:
BBcode:
HTML:
Hide post links
Show post links


Gfhug
Posts: 1858
Joined: Thu Jun 19, 2014 3:08 pm
Location: Near Andover, Hampshire,in D.O. Blighty
Great Britain

#24 Re: rolling road figures

Post by Gfhug » Tue Jul 02, 2019 11:39 am

If that's at the wheel then can't be far off the mythical 265 at the engine :swerve:
S2 FHC Light Blue

Link:
BBcode:
HTML:
Hide post links
Show post links


danxke
Posts: 14
Joined: Tue Nov 08, 2016 11:38 am
Germany

#25 Re: rolling road figures

Post by danxke » Tue Jul 02, 2019 3:28 pm

WebconUK wrote:
Tue Jul 02, 2019 10:55 am
A few years back, when we were still in the ECU business and had our own rolling road, we did some back to back testing on a standard 4.2 Etype , mainly to see how a well mapped ignition system affected the torque, but it also shows a stock SU equipped power curve alongside the same engine fitted with Webers, and below are the results we saw
Image
Hello,
the performance gains over the 123ignition appears to be remarkable, even with the SU carbs.

You are talking about this product, right? http://www.webcon.co.uk/shopexd.asp?id=16353

Is it discontinued?

regards
Dan

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

WebconUK
Posts: 14
Joined: Tue Nov 17, 2015 10:51 am
Location: Sunbury UK
Great Britain

#26 Re: rolling road figures

Post by WebconUK » Tue Jul 02, 2019 3:48 pm

Dan. That hardware kit is still available. The kit was originally destined to be a complete turnkey kit with ECU and loom, but we dropped that when we stopped ECU production about 3 years ago.

As an aside, we had 2 x 123 units pack up when we had the car on the rolling road. I don't think our development engineers were terribly impressed with them

Link:
BBcode:
HTML:
Hide post links
Show post links


Tom W
Posts: 269
Joined: Sat May 05, 2018 10:18 am
Location: UK
Great Britain

#27 Re: rolling road figures

Post by Tom W » Tue Jul 02, 2019 8:00 pm

That’s a useful increase. Interesting that the Webers provide peak torque at a lower RPM than the SUs. I’ve always wondered what difference, if any, Webers make. My car has Webers, but I haven’t had it on a rolling road yet so don’t know the power output. I’ve not tried a standard spec car, so don’t know it compares.

Was the 123 you tested with the one with the preset curves, or the tune model?
Tom
1970 S2 FHC

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

WebconUK
Posts: 14
Joined: Tue Nov 17, 2015 10:51 am
Location: Sunbury UK
Great Britain

#28 Re: rolling road figures

Post by WebconUK » Wed Jul 03, 2019 8:09 am

Tom. No idea about the 123 I am afraid. It was fitted on the car when it arrived and our plan was always to remove it as soon as possible.

And regarding the DCOEs, when we did our development, we found we had to end up changing more or less every calibrated part, and below is the setting we ended up with which really works very well on a stock engine. The F2 E tubes and 3.5 Aux vents made a big difference low down, so worth fitting them if you don't have them already

CHOKE 38
AUX VENT 3.5
MAIN JET 160
CORR JET 200
E/TUBE F2
IDLE JET 65F8
PUMP JET 40
PUMP BLEED 50
NEEDLE VALVE 225

Oh, and the power figures we state are always at the crank, not the wheels

Link:
BBcode:
HTML:
Hide post links
Show post links


Tom W
Posts: 269
Joined: Sat May 05, 2018 10:18 am
Location: UK
Great Britain

#29 Re: rolling road figures

Post by Tom W » Wed Jul 03, 2019 9:11 am

Thanks, that’s worth knowing.
Tom
1970 S2 FHC

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

abowie
Posts: 2359
Joined: Wed Sep 07, 2011 9:15 pm
Location: Australia
Contact:
Australia

#30 Re: rolling road figures

Post by abowie » Wed Jul 03, 2019 9:18 am

WebconUK wrote:
Wed Jul 03, 2019 8:09 am
And regarding the DCOEs, when we did our development, we found we had to end up changing more or less every calibrated part,
Interesting and very close to the recommended S1.5 setup in the Haynes Weber manual:

Choke = 38
Venturi = 3.5
Emulsion Tube= F2
Main Jet = 1.65
Air Corrector Jet =1.90
Idle Jet = 0.65 F8
Accelerator PumpJet = 0.40
Accelerator Pump Inlet Valve with Exhaust Orifice = 0.50
Needle Valve =2.00
Andrew.
881824, 1E21538. 889457..oops
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

Link:
BBcode:
HTML:
Hide post links
Show post links


danxke
Posts: 14
Joined: Tue Nov 08, 2016 11:38 am
Germany

#31 Re: rolling road figures: ECU users here?

Post by danxke » Wed Jul 03, 2019 4:32 pm

WebconUK wrote:
Tue Jul 02, 2019 3:48 pm
Dan. That hardware kit is still available. The kit was originally destined to be a complete turnkey kit with ECU and loom, but we dropped that when we stopped ECU production about 3 years ago.
Hello,
did you adapt the software/parameters of the ECU to the XK-engine, or was it more or less standard software?

I know that Mr Polite Person (hello!) uses an ECU plus a fuel injection, right?

Seeing your figures I assume that an ECU even without FI comes with dramatic performance gains.
Installing just the ECU plus the coil pack and the trigger wheel etc doesn't appear as super complex to me.

Probably a forum member can share experiences with the "ECU-only" approach.

kind regards
Dan

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Heuer
Administrator
Posts: 12717
Joined: Sat Mar 01, 2008 5:29 pm
Location: Nottinghamshire
Great Britain

#32 Re: rolling road figures

Post by Heuer » Wed Jul 03, 2019 5:23 pm

David Jones
S1 OTS OSB; S1 FHC ODB

Add your E-Type to our World Map: viewtopic.php?f=1&t=1810

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

abowie
Posts: 2359
Joined: Wed Sep 07, 2011 9:15 pm
Location: Australia
Contact:
Australia

#33 Re: rolling road figures

Post by abowie » Thu Jul 04, 2019 7:17 am

WebconUK wrote:
Tue Jul 02, 2019 10:55 am
A few years back, when we were still in the ECU business and had our own rolling road, we did some back to back testing on a standard 4.2 Etype , mainly to see how a well mapped ignition system affected the torque
Any chance you could share the ECU map you used, if it's not commercial in confidence?

It would be interesting to compare it to the EDIS maps.
Andrew.
881824, 1E21538. 889457..oops
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

Link:
BBcode:
HTML:
Hide post links
Show post links


danxke
Posts: 14
Joined: Tue Nov 08, 2016 11:38 am
Germany

#34 Re: rolling road figures

Post by danxke » Thu Jul 04, 2019 7:49 am

Heuer wrote:
Wed Jul 03, 2019 5:23 pm
Everything we know is here: http://forum.etypeuk.com/viewtopic.php?p=2553#p2553
I simply cannot wrap my head around the fact that just a coil pack and an ECU achieve a performance gain like that. Even compared to 123! Has somebody an understanding how that can be?

regards
Dan

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

WebconUK
Posts: 14
Joined: Tue Nov 17, 2015 10:51 am
Location: Sunbury UK
Great Britain

#35 Re: rolling road figures

Post by WebconUK » Thu Jul 04, 2019 9:11 am

abowie wrote:
Thu Jul 04, 2019 7:17 am
WebconUK wrote:
Tue Jul 02, 2019 10:55 am
A few years back, when we were still in the ECU business and had our own rolling road, we did some back to back testing on a standard 4.2 Etype , mainly to see how a well mapped ignition system affected the torque
Any chance you could share the ECU map you used, if it's not commercial in confidence?

It would be interesting to compare it to the EDIS maps.
We would be happy to share it, but as that product line was closed during the development of the Jaguar range, it rather looks as if the development calibration files were never signed off and hence never made it to the completed cal folder. Sorry

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

PeterCrespin
Posts: 4042
Joined: Fri Mar 05, 2010 8:22 pm
Location: Gaithersburg, Maryland.
Contact:
United States of America

#36 Re: rolling road figures

Post by PeterCrespin » Thu Jul 04, 2019 12:59 pm

danxke wrote:
Thu Jul 04, 2019 7:49 am
Heuer wrote:
Wed Jul 03, 2019 5:23 pm
Everything we know is here: http://forum.etypeuk.com/viewtopic.php?p=2553#p2553
I simply cannot wrap my head around the fact that just a coil pack and an ECU achieve a performance gain like that. Even compared to 123! Has somebody an understanding how that can be?

regards
Dan
Depends on 123 type and settings. I didn't like the look of the advance curves on my first-iteration 123, so there's no saying the engine in condition 1 was optimal to begin with. If your baseline is low....

The second power jump was never signed-off, so there may have been other variables.

Webers can be optimized for low rev/high gas speed filling (narrower venturis and longer trumpets), or for higher revs to suit a performance cam and exhaust etc.
1E75339 UberLynx D-Type; 1R27190 70 FHC; 1E78478; 97 XJ6L

Link:
BBcode:
HTML:
Hide post links
Show post links


Tom W
Posts: 269
Joined: Sat May 05, 2018 10:18 am
Location: UK
Great Britain

#37 Re: rolling road figures

Post by Tom W » Fri Jul 05, 2019 5:39 pm

There’s a few points at play here.

All these dyno power runs are done at wide open throttle. As there’s no vacuum advance at wide open throttle the 3D mapping element of the ECU controlled ignition offers no benefit. Where it will offer a benefit, is part throttle, drivability, though that won’t show up on the dyno graph.

Next point to consider is the total advance. If this is different between the two setups, then you could get a different power output. I expect the original factory settings are toned back slightly from the point of producing maximum power to protect the engine when it’s in slightly less than optimum condition. E.g. a bit coked up, or running on poorer grades of fuel. On a freshly rebuilt engine running on known fuel, you might be able to get a bit more advance without pinking. This isn’t really a product of The ECU though, the same could be achieved with a standard points distributor.

Then there’s the advance curve itself. Below around 3000rpm the distributor is within the advance curve. With a mechanical distributor, or the regular 123, the potential shape of this curve is pretty limited, so advance is not necessarily optimal at every point on the curve. With a mappable 123, or ECU controlled ignition, there are many more points that can be set at the optimum values. Also, each value isn’t dependent on it’s preceding or following value. Unless your engine is making maximum power before it’s fully advanced though, the shape of the curve won’t affect maximum power.

Electronic ignition offers benefits for dwell angle. Basically, the time the coil has to charge. On a mechanical distributor, this is expressed (and controlled) in degrees, so the charge time varies with RPM. Too short a time and the spark will be weak at maximum RPM, too long and the coil overheats at low RPM. Electronic systems control this as a duration, so can achieve the optimum value irrespective of RPM.

Switching to EDIS wasted spark ignition offers benefits for coil duty cycle. With a distributor, the coil has to fire 3 times per engine revolution. With wasted spark, each coil is now firing once per revolution. However the XK engine is relatively low revving so we’re probably not reaching the limits of coil charging time.

With the coil better charged, you can run a larger spark plug gap for a bigger spark. This will give a benefit of the spark was previously weak, but once you’ve reached the point that the mixture is successfully lit, it doesn’t offer much else. However, it does give you the option to up the compression ratio for more power, though this doesn’t explain an increase on back to back tests on the same engine.

Having said all of this, people who seriously race E-types are getting far more power than we’re discussing here, and running a points distributor. So I would conclude that getting the total advance spot on is more beneficial than the specific hardware you use to control it.
Tom
1970 S2 FHC

Link:
BBcode:
HTML:
Hide post links
Show post links


MarekH
Posts: 847
Joined: Wed Jul 21, 2010 8:30 pm
Location: Surrey
Great Britain

#38 Re: rolling road figures

Post by MarekH » Fri Jul 05, 2019 5:59 pm

There are lots of very sensible observations in your post Tom.

The most notable is that the "rolling road figures" are really just the end result of someone purchasing an A4 graph with a squigly line on it, whereas a 16x16 map of load versus rpm for both advance and fueling means the purchaser has control over how the engine performs at all times. Whilst the tuner may have "helped" for the odd time when your driving just happens to be along the line, the tuner does nothing for you under any other scenario. I spent a day watching and quizzing one such tuner. It was very instructive that his entire garage was full of cars. I asked about each of them and they were all "chipped" cars with blown turbos, blown head gaskets , holed cylinders, etc, etc and the clients all wanted more power and were going from tuning upgrade to to tuning upgrade - in the most expensive and destructive way possible.

If you are going to a rolling road, don't just buy yourself an A4 graph with a line on it. You won't be happy. Ask for a 3D advance map with a view to maximising either torque or economy at all revs and all loads. That might indeed give you a better driving experience.

kind regards
Marek

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

politeperson
Posts: 902
Joined: Tue Jun 07, 2016 8:26 pm
Location: Boston UK
Great Britain

#39 Re: rolling road figures

Post by politeperson » Fri Jul 05, 2019 6:31 pm

Very true Marek.

Don't forget, those track 400 bhp XK engines make almost no power whatsoever below 3,500 rpm, cost the best part of £75k and might last one season if you are lucky. They are really suitable for racing only (unsurprisingly).

My last rolling road session lasted 4 hours. Emerald were very careful to map the car on a variety of throttle openings, as you would with a road car.

Yesterday another esteemed forum member-(Daimlerboy!) and I drove it to The Festival at Goodwood from Boston and back again. Stuck on the M25 in the heat for an hour idling. No issues. 33.5 liters of fuel at Midhurst after 205 miles- 28.85 mpg! Yes, we were both surprised. My maths must be wrong but I do have the receipt.

458 Miles in total, went like stink. Another great E type day.
James

L.J.K. Setright was right.
"You just cant beat a good E-type"

Link:
BBcode:
HTML:
Hide post links
Show post links


MarekH
Posts: 847
Joined: Wed Jul 21, 2010 8:30 pm
Location: Surrey
Great Britain

#40 Re: rolling road figures

Post by MarekH » Fri Jul 05, 2019 6:42 pm

You should have popped in on the way home.
I am just off the A3 near Guildford.
kind regards
Marek

Link:
BBcode:
HTML:
Hide post links
Show post links

Post Reply Previous topicNext topic