Just got back from local dynojet days ago, the result is not so great. The shop owner was saying my clutch is not holding the power, he said rpm/mph(gear ratio) on the graph should hold flat. is this true on high whp Honda? This was 3th gear pull. A/f is low 11 on c16.

Car spec:
OBD1 GSR
Benson sleeved block 83mm bore
CP Pistons & rings 9:1
Manley Rods
00’ ITR camshafts
Stock gsr head with SuperTech Stainless Steel valves, valve springs and titanium retainers
Full-Race B series ProStreet turbo manifold.
Full-Race B series ProStreet 3” down pipe
Full-Race T3/T67 H.O turbocharger
LS transmission
Clutch specialty stage5 6-puck un-sprung iron disk 400ft/lb capacity



Thanks

 

Dude, yes. If you take MPH/RPM or its inverse it should be Constant and that should be not necessarily the "gear ratio" but a useful ratio nonetheless. If it changes one of two things is happening. Clutch slipping or tires slipping (or electronic error). It depends how they measure speed. If they measure rpm from the car and speed from the dyno, then the tires *could* be slipping. If they measure them both from the car, then the clutch *is* going.
Id make sure your tires can put down 300wtq.
Also you might try smoothing out that vtec engagement or whatever happens at 5k Looks like the jump in power corresponds with the traction/clutch loss.

Heres how you figure it out if the above didn't narrow it down...
1) go back to the dyno
2) look at your speed in the car and the speed that the dyno reads (have someone *yell at you as you go)

if the speed in the car is higher than the dyno by more than a little bit (2-5mph) then the tires are slipping
if the speeds are the same, the clutch is slipping

At 9k I have the car reading 110mph and the dyno reading 92mph *if the tires are slipping. (on the 25psi run) In other words, it should be obvious at high speeds.

Mad props by the way, looks like if you had the head for it you could keep on the power to 10k. Then you could shift to 8k and keep 500hp the whole time.

HTH



Modified by buzz1167 at 8:10 PM 8/14/2006

 

you should dyno the car in 4th gear w/ that much power on a dynojet. u probably are breaking the tires loose on the dyno

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mase &raquo;</TD></TR><TR><TD CLASS="quote">you should dyno the car in 4th gear w/ that much power on a dynojet. u probably are breaking the tires loose on the dyno</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mase &raquo;</TD></TR><TR><TD CLASS="quote">you should dyno the car in 4th gear w/ that much power on a dynojet. u probably are breaking the tires loose on the dyno</TD></TR></TABLE>

 

I can understand why should be in 4th gear pull, but the thing is I was on 225/50/15 drag radials, and also I compared my old dyno pull on regualr street tire(same 3rd gear) the graph still make no sence to me. I will post up the graph when I got home today.

thank to all you. so rpm/mph is not flat is either clutch going or tire spin on the dyno right? and yes I will go back dyno soon.

Thansk
Will

 

Is there any limit to how fast people should go on a dyno? I don't know all that much about how fast they are made to go... 9k in 4th is gonna be faster than i've seen a car go on one before.
I've never had the problem before b/c I dont have badass cars like that, the people I know do runs in 4th, but the aren't revving nearly that high.

Gonna land you some more power if you get traction, I wanna see another dyno.


Edit: didn't get to see your post: The radials might hook up on the ground great, but some dynos can be kind of slippery/worn smooth so the drags might not be good enough in 3rd.

 

I rev to 10.5k in 4th, over 155mph. The dynojet will go to 200mph.

 

bad thing about the dynojet, you have to run high roller speeds, ive gone numerous times over 150 mph, but id be lying if i said it didnt make me nervous. if anything happens at 150 mph and it takes quite awhile for those rollers to slow down...

not to mention most people dont have wheels properly balanced when they hit the dyno... that makes it even worse.

but yeah, do a 4th gear pull, it will probably solve ur problem, and you will notice the graph will look different

 

The dyno will shut down at 200 mph - I know this because I have done it a couple of times.

 

ho..btw, can anyone here giving a example to see how different powerband will be between 3rd gear and 4th gear pull?

Also I don't thinks the car the making the power that it suppost be. the power gain from 20psi to 25psi is bad, isn't it.

Also, I really don't thinks tire was spinning either, friends told me the very last pull the car sound's making big power jump, but the result wasn't what I was expecting.

Thanks
Will

 

anyone?