recently have been having a few problems with regards to a misfire, so last night cleaned the spark plugs and thought it was ok (plugs had only done about 400 miles).

Only happens at high RPM and it happened on every run

Took plugs out there to check the gap, and seemed fine, so not much I could do even though they said if it was a plug issue they would let me run it up again.

The last run, the car had to be run at about 70% throttle and even then still misfired...

Will change the plugs and leads, and if it doesnt cure it, I'll have to get Karl to have a look at it for me...

Despite all the above, here is the graph they printed out for me....

 

Get Karl to look at it mate.....im sure he will sort it after everything you have had done

 

why so much transmission loss??

 

Shame about the missfire but good power all the same mate!

 

Dunno mate, torque was down about 75ft/lb as well, guessing its to do with a proper run not being done...

Still, I drove it back

 

Anyone any thoughts?

 

1. 93bhp Transmission loss? There's no way in the world is that right.

2. What cam have you got?

 

Fook knows, will get Karl to have a look, have messaged him tonight.

 

still good fiure Stu even though you could not get a proper run.

 

Yes, but not taking anything away from Stu, the dyno measures power at the wheels and for that it shows 196bhp, which is by all accounts poor for the spec. I think there was a fault with the run personally.

 

I don't think the Rollers were very good yesterday, the power figures seems slightly low on a lot of cars, and the torque figures were all very low, even using the correct NM to Lbs/ft conversion.

My mates saff ran 415BHP, and 315 Lbs/ft, but recorded a 196BHP transmission loss - A lot of people seemed to be missing 50+ Lbs/ft of torque off thier expected figures odd.....

And Stu's car, I think about 30 people are now suffering from tinitus from the expolsions coming from the exhaust

 

Looks like yesterday was "National Lose power on a Rolling Road day"

 

if thats the case then Gary's Evo will be over 700 bhp

 

....and my 1600CVH will be 350bhp on 20psi!!

 

what would cause such big tranny losses for the day? Incorrect RR settings?

 

Hey Stu!

Nice to meet ya yesterday

What exactly did Curtis say to you about it then as i couldn't over hear the convo properly.

It did sound a bit like boost cut to me but i guess it all depends on what the boost limit is on your ECU. It seems a little coincidental its happening now the weather is colder aswell if you get me

 

the operator braking on the run down to get the flywheel figers up

 

Perhaps some people on here best do a bit of research and actually find out how a MAHA rolling road works first, before slagging it off.

Torque is down on a MAHA compared to say a Dyno Dynamics, where as power is slightly up compared to a Dyno Dynamics.

Ignore the PAW (on a Maha) as these rolling roads are geared towards Fly Wheel calculations.

 

Hey up mate, good to meet u 2!

He said it might have a bit of overboost, or plugs might be knackered!

 

LOL!

Bloodyhell, check the losses. Someone fitted 4wd?

How can ANY rolling road be geared towards flywheel calcs when flywheel calcs are TOTALLY calculated (ie guessed) from WHEEL numbers?!?!

 

As soon as it back fired the first time i said it sounded like boost limit, but even at 3/4 throttle it was popping and banging, but then that said it more than likely would of been boosting just as hard.

Have you checked the plug gaps like Curtis suggested? Might be worth turning the boost down a touch aswell to see if that cures the problem, you won't have lost anything if not.

Fairplay though, that car had some serious grunt

 

For those people that weren't paying attention the RR operators did actually say to ignore the corrected wheel figure because of the fact the rollers pinch the wheels and present twice the contact surface compared to when the car is on the road!

The flywheel figure is the accurate reading and the one you should be looking at for this rolling road.

 

No flywheel figure is ever accurate on any rolling road.

Fact.

 

IMO Stu...the RR run was a farce....as soon as it misfired like it did, it was never going to improve.

For them to try it time and time again was not a good idea at all! hopefully no damage has been done to your cylinder head in particular!

trying to get an accurate figure by using part throttle and driving through the misfire was a bit strange too

whether it's a plug fault or summat else i don't know, but i'd personally speak to Karl about some Denso Iridium, have the gap on that cam trigger doofa checked and maybe try new leads.

personally i think it's plugs though.

 

bud-weis were you there?

 

Yeh he was there, helped me check my plug gap.

Ive got some new 071C's Martin, should be gapping them later and seeing..

I wonder if it is boost limit

I suppose Karl would have to have set one?

 

I'm still interested to know what cam it has.

 

Has to be said, I was quite shocked they didn't put a probe up any of the cars exhausts to monitor the AFR either .... thought that would have been a very good idea to keep an eye on peoples engines.

Figures were very strange, operators said Torque was at the fly, and everyones was very low for their spec, even on cars who hadn't changed spec since last time they were RR'd. Power seemed sensible at the fly figures, but wheel figures were all over the place.

Have to agree with Stavros here and say that its hard to know what to belive - The only car I saw make what was expected or thereabouts was Si's saff, which made 397 BHP and 393 Lbs/ft, which was just about right for the spec, a lot of other cars seemed way off, even with no apparent problems.... odd

 

hmmm, i thought mine was a bit low too. Mines done 241 at interpro, and 242 at powerstation in may this year. My run was 229 this time, although with 3lbft more torque (wow ). I've compared the drag factor (or whatever its called (i dont have the graphs in front of me) on the two powerstation graphs and they are different - why would this be? I was also surprised as on my run in May this year, the car was only overboosting a third into the hashed section, this was fixed for the weekends run so the overboost peaked just at the red section then droping back exactly to the blocked in section (just as i believe it should?). The car felt quicker after the actuator was set correctly, but it produced less

 

If its any consolation, i was chuffed with the figures my trackday shitter produced

Plus it sounded good bouncing into the 8000rpm rev limiter !!!

I remember one of the powerstation guys saying something about the transmission losses being all over the shop, but cant remember exactly what he did say

 

i'm going to get mine power run somewhere else i think.

 

Go to Engine Advantages or Power Engineering, will be 579BHP and 760 Lbs/ft

 

all the graphs in PDF format can be found here

http://www.rs-mania.co.uk/forums/ind...=0#entry234214

 

Ahhh ok didn't know he was there aswell

Well yea Karl probably did set one, but as the weather gets colder and the air gets denser its more likely to hit the boost limiter

If the new plugs don't make any difference it'd be worth finding out what the boost limit is set as, i really don't think its anything major though as they nearly got a clean run at the slightly lower throttle.

 

As far as im aware its not standard practice but they are more than happy to do so if you ask, after all though its a power run for Ł30 (noramlly around Ł70 there) and not a mapping session if you get me

 

If you mean my car, it has a newman solid lifter cam w/ solid followers..

Changed plugs yesterday as was only firing on 3 and feels like a new car again. Yet to test high boost in 3rd though..

 

chop chop then its a dry day

 

 

My Escort cossie has just had a brand new from blank BD 14 Newman cam put into it, should be interesting to see how good it is, certainly looks the part great price too from Woodford

Stu those misfires on Saturday were comedy sounded like bin-laden was in the workshop

 

What fact because Sir Issac Newton said it wasnt or fact because thats what everyone says or fact because you have managed to measure the flywheel power of an engine incar and then measured it against what a RR says? I do find these statements quite funny as do you or anyone know how different these figures would actually be. I fully appreciate what you say though.

As regards to your understanding of how a RR works you really need to research on how a MAHA is both set-up and works. The simple fact is it is not meant to give any form of meaningful PAW's, regardless of what your logic dictates. I would explain, but I would get it all wrong even if I have had it explained to me a thousand times before.