Weber vs Holley revisited

289 dynoed back to back.

 

[BenL]

Which Holley did you use?

 

Reed's 750cfm

 

[BenL]

[ QUOTE ]
Reed's 750cfm

[/ QUOTE ]
Does that one have two bowls?

 

Yes

 

[Ron Earp]

If the power is in hp, and the torque in lb ft, then why aren't the two equal at 5225 RPM as they should be, by definition?

 

Strange on the dyno sheets torque and HP cross at 5250 but not on these graphs,any explications?

 

[Steve Toner]

The torque & HP are plotted on different scales. It looks pretty close to me, given the fairly low resolution of the graph...

 

[Ron Earp]

The upper curves intersect at about 4250, pretty far off. Don't know why since the dyno typically measures torque, hp is calculated from that, so by definition they have to be equal.
Hp = torque x RPM / 5225

 

[Steve Toner]

Looks to me like at 4250, the torque is about 350 (left scale) while HP is about 290 (right scale)...

So the facts that the curves physically cross there doesn't mean anything, does it?

 

[Ron Earp]

Well, lets see,

hp = torque * rpm / 5225

290 = 350 * RPM / 5225, true or not?

Which works for the resolution we can get off the graph.k. If it makes 350 lb ft of torque at 4250 then it must make 285 hp at that same RPM. Close enough.

It works here - what is throwing me off is the two axis graph and the poor resolution. If you look at 5225 RPM and get torque you get around 350. Same for hp, around 350. So, it is just the way the graph is that is screwing me up., nothing wrong with the dyno results at all.

 

[Gary Gibbs]

Yes the dual axis ploting makes things look different. BTW I believe the constant is 5252.

 

[Ron Earp]

Yep, I stand corrected, R

 

[Malcolm]

Well for me this discussion is simple. At the club track day I saw a battery run virtually flat trying to start a Webber car but my trusty Holley fired on the button all day! So of course I am biased!

 

[Max Walter]

Well mine is to be changed from Weber to Holley in the near future. I hope it improves the reliability etc as much as people tell me it will. I killed a battery too (whilst at Le Mans).

Max

 

[MWGT40]

I am going the opposite way - I have two Holleys at present (a 650 and a 750 double pumper) and am moving to Weber 48 IDAs - awesome! /ubbthreads/images/graemlins/cool.gif