Rolling Road Figures

Albrecht said:
So where are all the "you can't believe dyno figures" type posts we normally see when such topics are discussed?

If this data came from Rebello it would have been dismissed as hugely optimistic by now....
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Its really too hot today to be bothered but since you ask and have mentioned the R word then lets play................................................;)

The data didnt come from Rebello but if Dave Rebello had dynoed this engine it would have made 180bhp and he would have claimed it was due to the "custom Rebello header and filter" :D:D:D

you can't believe dyno figures
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You can if you want... its not a crime.:)
I didnt want to believe the dyno figure on my print out this week but I have had to accept that 234fwhp is all that my 3.0L VG engine is making cos TWO independent and highly respected concerns say so:eek:
I guess I sholuld have imported a Rebello one instead of trying to build one here in the UK.:rolleyes:
The upside is it makes 218.9ftlbs of torque and pulls strongly from 2500 all the way to 6500.
Just all figures on paper of course and as interesting as they might be to some people the real test comes on Sunday at TOTB:lol:
 
In my experience the tolerance and difference in dyno figures is less than that of the drivers ability.:driving:

The stopwatch is the best dyno. :thumbs:

So we have gone way off topic about what seems a healthy standard (almost) engine.
 
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pmac said:
Its really too hot today to be bothered but since you ask and have mentioned the R word then lets play................................................;)
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Or rather, let's not.

It seems that dyno figures are more dependent on whose they are than on anything else.

The usual old ********, then.

Carry on, as you were....
 
Carry on, as you were....
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OK will do.
Ive made a couple of Rebello comments.;) That will do:D
Nuff sed

I know from speaking off forum that the OP has a really nice un molested HLS30.
And Im sure he is very happy with it.
 
pmac said:
I know from speaking off forum that the OP has a really nice un molested HLS30.
And Im sure he is very happy with it.
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I'd just like to say - speaking ON forum - that I'm really happy for him.

Brilliant!

:rolleyes:
 
Anybody here in the (brilliant!) Zclub forum care to post a factory stock dyno data curve graph?

Or will it be down to me...?
 
Did they change the quoted output between engine changes? As in the L24 with the e30 head and its slightly higher compression against later versions that became more emissions friendly? As a side note was there any official type announcement from the early 69/70 cars to the later ones?

Alan you've got me, I had a little chuckle though as I thought that there was a nice curve printed in one of the brochures I've got but I was wrong, just tech data.
 
chrisvega said:
Thanks Albrecht, speaking ON forum, your concern is really touching :rolleyes:
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You get my point though, yes? It's nothing personal.

It's just that time and time again I see the same people telling us that dyno figures can't be trusted, are meaningless taken in isolation, and that rolling roads are simply tools for tuning with. All of which is generally accepted to be the case.

Then there's the scorn poured on certain USA-based engine builders with relation to the dyno figures they quote for their products, and the finger pointing at the USA's "optimistic" figures in general. I've even seen an Australian engine builder quote his own apparently optimistic figures whilst dissing those of others. It all gets silly.

And yet here we are with your figures being taken completely at face value and without question (apart from Rob's "on the face of it"), as though the rolling road that produced them is 100% accurate and the figures are spot-on. Have we found the world's first 100% accurate rolling road unit?


So here's a few straight, no spin questions for you:

What market was your engine originally built for?
What cylinder head casting does it use, and what is the (stock) compression ratio?
What distributor unit is it fitted with?
Is the cam timing 100% stock?
Do you have any theory as to why your almost stock L24 is making its peak torque at over 5k rpm?

Thanks.
 
I'll put my stock 240Z on a rolling road if anyone cares to pay for it. :p

I'm happy with the power and the way it runs having tuned it on my drive.
 
Rob Gaskin said:
I'll put my stock 240Z on a rolling road if anyone cares to pay for it. :p

I'm happy with the power and the way it runs having tuned it on my drive.
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It wouldn't help though would it as its not the same machine on the same day with the same conditions and would still be a wheel measurement with the associated losses of a 40year old drive train?
 
If you get it to Devon I'll go 50-50 ?
If you've tuned the carbs and no balancing/tweaking required will cost just £ 48 for an hours time on the RR. Great value ? Need to give them 3 or 4 weeks notice though.
 
So these rolling roads would be more useful for 'before and after' printouts on modifications or tuning on the day so you can get an idea of like for like improvements in power?
 
chrisvega said:
If you get it to Devon I'll go 50-50 ?
If you've tuned the carbs and no balancing/tweaking required will cost just £ 48 for an hours time on the RR. Great value ? Need to give them 3 or 4 weeks notice though.
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Chris, good offer and good value. If I lived closer I'd do it and bring my modded 240Z too for comparison.
 
Dale said:
So these rolling roads would be more useful for 'before and after' printouts on modifications or tuning on the day so you can get an idea of like for like improvements in power?
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I think that pretty much describes exactly what they are most useful for.

It certainly seems to be the best way to treat the figures they give. You could have your car rolling-road dynoed at Mr A's, then drive to the end of the same road and have your car dynoed at Mr B's. If they both gave you the exact same figures it'd be something of a surprise to say the least.

Mind you, further up the thread you can see somebody claiming that two different dynos - on two different days - gave the same "234fwhp" figure for the same car. What an extraordinary coincidence.....
 
At least the owner took the time to post up the graphs, generally owners with "high performance" engines from "reputable" builders seem to be a little more shy....but were talking two different types of claim here arnt we :rofl::p
 
I've used a rolling road local to me to do a bit of tuning both with the l series and the 1j under various states of tune. I think the figures they give are pretty accurate (392bhp at the fly) and this is verified with a 11.6@124mph run down the strip. Car was 1240kg at the time. I try not to dismiss other rolling road figures a I think if my one is accurate then there must be others out there that are the same. I do also believe that some just give you figures with the intent on just making you go away happy.
 
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