Dyno runs

[longassname]

Joe,

I doubt the dyno operator would have known the correct drivetrain loss to figure in to determine flywheel hp from wheel measurements. I only know from experience with dynoing svx's. There's really no way to figure what is correct for your friend's car without asking the dyno operator what he did. It's both possible that your friend's transmisison is on the way out and the #'s given by the dyno guy include some % added back to account for drivetrain loss and possible that the #'s are wheel #'s and the dyno just gives optimistic results.

On an acurate dyno an svx with a good auto trans measures right around the same as a wrx with a manual trans--just a few hp less than the wrx.

[SVXRide]

As you can see from the results that gest24 got when he dyno'ed his car after Young Tom did the 6spd and intake cams, there is variability between dynos (no shock here). What I have done is made sure that each of my dyno runs is on the same dyno to maintain consistency between runs. This will be the 3rd time I've been on Altered Atmosphere's dyno.
-Bill
p.s. picked up the car from the shop I did the flexplate replacement at and put the stock rims/tires back on before driving it home...to say there is a visual difference between 55offset/225/50 and 38offset/275/45 is probably an understatement

[Trevor]

I have been involved in the development of the electronics for a rolling road dynamometer which was to have been manufactured locally, so am fully aware of how these things work. The are many contingencies which prevents even repeatable accuracy, much less accurate calibration. Furthermore I was at one time sponsored in motor racing, by an organisation specialising in using such a machine, thereby gaining practical experience.

The limitations became patently obvious when differences in figures which caused concern, were not born out in lap times and race results.
I therefore only relied on the machine to provide comparative figures during a single test application. Even then there are many factors which may cause errors, varying from one machine to another. Those which incorporate a water brake are most suspect.

[svxistentialist]

Originally Posted by Trevor

I have been involved in the development of the electronics for a rolling road dynamometer which was to have been manufactured locally, so am fully aware of how these things work. The are many contingencies which prevents even repeatable accuracy, much less accurate calibration. Furthermore I was at one time sponsored in motor racing, by an organisation specialising in using such a machine, thereby gaining practical experience.

The limitations became patently obvious when differences in figures which caused concern, were not born out in lap times and race results.
I therefore only relied on the machine to provide comparative figures during a single test application. Even then there are many factors which may cause errors, varying from one machine to another. Those which incorporate a water brake are most suspect.

That's pretty interesting Trevor, and seems to bear out what others have experienced.

Notwithstanding your comment on calibration above, would there be a case for a government institute devising a rig to test each one of these devices once a year say? Here in Ireland we have the NSAI, who check up on everthing that purports to measure or to weigh or whatever.

It might just inject a measure [pun intended] of realism to have a comparator that shows what %age the dynos are out, to have them certified and presumably re-adjusted once a year.

Would it work?

Joe

[Trevor]

Originally Posted by svxistentialist

That's pretty interesting Trevor, and seems to bear out what others have experienced.

Notwithstanding your comment on calibration above, would there be a case for a government institute devising a rig to test each one of these devices once a year say? Here in Ireland we have the NSAI, who check up on everthing that purports to measure or to weigh or whatever.

It might just inject a measure [pun intended] of realism to have a comparator that shows what %age the dynos are out, to have them certified and presumably re-adjusted once a year.

Would it work?

Joe

Sorry, but don't think so Joe , too difficult to apply and would increase your taxes one way or another.

However this should be applied in respect of wheel alignment machines, which are so often not checked and are faulty. In this case, it is measurement which are being sold.:confused. I have often proven them miles out, using basic fool proof techniques.

Cheers for us poor consumers, Trevor

[NeedForSpeed]

Bill,

Just puttin' on the second coat now!!

Originally Posted by SVXRide

Ron,
So, get in your car and start driving now
-Bill
p.s. I think I'll need those parts from you in about 2 weeks...

[TomsSVX]

Bill, best of luck to you. Lets hope for a numer over 180 this time Wanna see close to 100 more? I could come along .........






Then I realize how broke I am and strapped for time and say..."nevermind "

Tom

[Earthworm]

Originally Posted by NeedForSpeed

Bill,

Just puttin' on the second coat now!!

<George McFly>Now Biff...</George McFly>

[sperry]

Originally Posted by svxistentialist

This being so, then Mal's car will only have produced 133 at the wheels, and then had the estimated 30% added to that to give the 173 quoted. If this is the case, then Mal is down 67 hp from the 240 he was expecting.

Just an aside... when I dyno'd my stock SVX, 133hp is right about what it put to the wheels.

[NeedForSpeed]

Sperry?

What kind of dyno?
Where, in Reno?

[sperry]

Originally Posted by NeedForSpeed

Sperry?

What kind of dyno?
Where, in Reno?

Mustang Dyno, in Sacramento on the date in the picture. Mustangs read notoriously low, but that 134 was 1 hp more than a 2.5RS w/ intake & exhaust, which sounds about right IMO. 200k mile 4EAT SVX should make about the same whp as an 80k mile 5MT RS.

[oab_au]

Originally Posted by sperry

Mustang Dyno, in Sacramento on the date in the picture. Mustangs read notoriously low, but that 134 was 1 hp more than a 2.5RS w/ intake & exhaust, which sounds about right IMO. 200k mile 4EAT SVX should make about the same whp as an 80k mile 5MT RS.

Were there any exhaust modifications done, or was is it standard.

Harvey.

[sperry]

Originally Posted by oab_au

Were there any exhaust modifications done, or was is it standard.

Harvey.

On the SVX or the RS?

The SVX was bone stock, right down to the OEM paper air filter element.

The RS had a short-ram intake and a header-back exhaust if I remember correctly.