Westfield Duratec Rolling Road Figures

[Cleggy the Spyder Man]

I know this has been a past topic - and that Westfields claims of 205bhp are shall we say a little optimistic ..

Has anyone had there Duratec rolling road tested and what did it achieve -

Mine I believe has the later webcon throttle bodies and has cat exhaust - all standard stuff from Westfield - It was purchased as a complete engine from Westfield

[Barry Ashcroft]

David Chambers had his done at NMS and it was 170bhp,

Ported head new cams and a bit of Troy's magic got it to 224bhp

[Cleggy the Spyder Man]

How can the manufacturers figures be so far out?

What are the variables - the only one I can figure out is air temperature and set-up of the throttle bodies, surely the engine manufacture cannot vary that much

I am very curious to know if these low actual rolling road figures that have been around on the forums are one offs or literally every duratec that has been on a rolling road comes back with 170 ish BHP?

[samcooke]

Have a search for rolling road, it's been discussed lots on here. Apparently the roads themselves can easily vary by 10% or more.

[Norman Verona]

Manufacturers figures are probably at the flywheel.

RR can differ but quite a margin taking into account calibration of the RR and computer adjustments to the data fed in (like air temp).

The only real test for useful power is done with a stop watch

[Glen H]

When mine was a standard Duratec on the Raceline T/Bodies and Webcon ECU it went to Northampton Motorsport a few times and got 185bhp with a standard Westfield exhaust with integral Cat, back with new non cat exhaust and extended inlet it went to 187bhp but with loads more mid range.

New cams, pockets machined into the pistons, bit of DIY porting and some of Troys magic gave it 226bhp (also had the Crank & Pulleys keyed)

[stephenh]

Your right Norman, but usually the rolling road will estimate the power loss through the transmission train, and add it to the power at the wheels. Troy did that on his old rollers by measuring the drag on the rollers when he de-clutched (and lifted off the throttle of course!) from max. revs at the end of a power run. I dont know if his new roller works the same way.

Cleggy, my 2008 duratec, just run in and using a factory trackday silencer (worth possibly 5 bhp max.) made 187 bhp at 7050 rpm on Troy's old rolling road. Power was still rising slightly if IRC, so it might have made 190 at 7200, but the ignition cut-out was set at 7050 rpm.

Troy said it was the highest power output he had seen from a duratec on  standard head and standard camshafts.

Westfield are carefull not to make max power claims these days, they are well aware of how inflated most of the power claims are. If you ask them the question they will now say "around 190 bhp", and that is on the latest KMS tappered throttle bodies which I have, which I think have 50mm throttle butterflies. I haven't measured them ,but that is what they look like.

I believe the various tuning firms base their claims on engines out of a car on a testbed, probably with no air filter, no engine driven fan, possibly not even driving an alternator, probably no silencer, just a tuned length pipe. It's very artificial. As Norman says, how quick does it feel? Mine is like greased lightening. I've never experienced accelleration like it, and I've been in many fast cars over the years.

[Cleggy the Spyder Man]

Just been out for a spin, and yup it feels b****y quick as always, I am certainly not complaining of loss of power ..

Just curious on those figures

[simonbell]

I have always been dubious about the 200bhp out of a relatively std duratec claims. Westfield use Webcon don't they. I know Webcon claim 205bhp for a duratec with throttle bodies.

I had std duratec with raceline TB's, std head, std cams etc and it was 185bhp which I believe is the norm for that level of tune. Mine was mapped on rolling road at Emerald

Just fitting cams, pistons, rods and ported head, hoping to see 250bhp  

[Cleggy the Spyder Man]

If only I had bottomless pockets -

Glen H - how much did your engine upgrades cost you if you dont mind me asking?

[stephenh]

Simon, your out of date, Westfield stopped fitting the Webcon Alpha system over a year ago. They now use the Dutch KMS throttle bodies and ecu. That's what I have, mine was one of the first, built early last year, and registered new on 4th. March!

[Thrustyjust]

mates Westie with standard Duratec 2 ltr, throttle bodies (short ones under the bonnet), Emerald ECU with a catless exhaust ( Westfield system) was on the rollers at Emeralds.Dave Walker was stunned to see 197 bhp from it. Even got out shaking his head and went to 'have a chat with Carl' before admiting to unbelieveble power from a standard engine.He wanted to have another go and rev it a bit more to try and crack the 200bhp, but my mate's trousers were twitching and declined the event to happen.This was on an engine which had 1500 miles on it from the box.

[Northampton Motorsport]

Hi Guys, we have never seen a standard spec Duratec make 200 bhp. As Stephen says his was the best standard Westfield Duratec we have seen so far, and most make between 170 to 175 bhp.  

On both our old sun ram 12 and the new Superflow the dyno does a cost down run to measure transmission losses which is then added to the wheel hp figure and corrected for barometric pressure, air temp and humidity to give a final corrected flywheel figure.

There is lots of debate about this method as a lightly loaded gear train (as it is on cost down) will absorb less power than a heavily loaded one but after nearly 10 years of dyno’ing cars I really believe this method is better than just adding a % for trans losses which is how Webcon arrived at the 205 bhp figure.  We have run cars with identical engines but with different gearboxes and the wheel figures and trans losses were different but when added together the net flywheel bhp was the same to within 2 bhp. Using the % method in this instance would have resulted in 2 completely different readings, the engine’s were completely standard Vauxhall XE’s fitted in Astra GTE’s but one had its original Astra box and the other had a box from a Cavalier fitted which had different ratios. I can’t remember the exact numbers but they were with a gnat’s whisker of 150 bhp which is book power for the XE.

We have also run a few Fiesta ST’s and they make 150 bhp in standard trim so I have no reason to distrust the dyno figures. One project car we have been steadily upgrading made 149 in standard trim before we touched it, then with roller barrels and Omex 600 installed it made 172 and then with the standard Fiesta exhaust replaced with a miltek 4 branch manifold, hi flow cat and system it then made 184.

What we have realised with the Duratec is a) it is a stonking engine and has loads of potential and b) it is hugely sensitive to little things like shape of intake manifold, adequate filtration, exhaust etc etc.

Just last week we saw a 10 hp gain on a 750 kits race car after changing a poorly designed inlet manifold with a better flowing one from Titan.

[markcoopers]

So my mighty Zetec 1.8 monster can still kick sand in the Duratecs eyes          

[Thrustyjust]

Hi Guys, we have never seen a standard spec Duratec make 200 bhp. As Stephen says his was the best standard Westfield Duratec we have seen so far, and most make between 170 to 175 bhp.  

On both our old sun ram 12 and the new Superflow the dyno does a cost down run to measure transmission losses which is then added to the wheel hp figure and corrected for barometric pressure, air temp and humidity to give a final corrected flywheel figure.

There is lots of debate about this method as a lightly loaded gear train (as it is on cost down) will absorb less power than a heavily loaded one but after nearly 10 years of dyno’ing cars I really believe this method is better than just adding a % for trans losses which is how Webcon arrived at the 205 bhp figure.  We have run cars with identical engines but with different gearboxes and the wheel figures and trans losses were different but when added together the net flywheel bhp was the same to within 2 bhp. Using the % method in this instance would have resulted in 2 completely different readings, the engine’s were completely standard Vauxhall XE’s fitted in Astra GTE’s but one had its original Astra box and the other had a box from a Cavalier fitted which had different ratios. I can’t remember the exact numbers but they were with a gnat’s whisker of 150 bhp which is book power for the XE.

We have also run a few Fiesta ST’s and they make 150 bhp in standard trim so I have no reason to distrust the dyno figures. One project car we have been steadily upgrading made 149 in standard trim before we touched it, then with roller barrels and Omex 600 installed it made 172 and then with the standard Fiesta exhaust replaced with a miltek 4 branch manifold, hi flow cat and system it then made 184.

What we have realised with the Duratec is a) it is a stonking engine and has loads of potential and b) it is hugely sensitive to little things like shape of intake manifold, adequate filtration, exhaust etc etc.

Just last week we saw a 10 hp gain on a 750 kits race car after changing a poorly designed inlet manifold with a better flowing one from Titan.

Strange, as Troy mapped my Zetec after I had the injectors cleaned and a few other bits and I had the print out from Emeralds and we compared the figures on the plots and admitted to both rollers being very close to power outputs.