Heya guys,

I dynoed my standard car last weekend just to get an idea of how much power my car is making in standard form before I start modifying it and stuff

The dyno operator used 3rd gear on the dyno and the car squeezed 310whp but all the other cars was using 4th gear on the dyno , did he do it because my car a 6speed or what ???

Will the car putting a lot lower power output if 4th gear was used instead of 3rd ??
I asked him right after and he said the power output of the car wouldnt change much at all but torque figure will be quite different

Any input will be gladly appreciated

Cheers

 

from my experience it usually depends on the transmission the car has and also the power level the car is making. Usually on low HP cars (below 250whp) 3rd gear will show more peak power. High HP cars u have to do 4th gear pulls. On a 4th gear pull, the turbo has more time to spool up so the power band will be better on the dyno

 

Your right on my car i sued to run third gear dyno pulls all day longm, However once my numbers for torque got big along with the Hp numbers we had to switch over to 4th gear cause in third we were ripping the tires off the dyno.

 

alot of people boosted dyno in 4th because of traction but also its generally been said that you want to dyno is the gear that is closest to a 1:1 ratio. other factors come into play though and ratios are not alwasy spot on to do that.

 

I agree 100 %

 

we use 3rd gear for the main tuning and then a few last 4th gear pulls for brushing up.

this is with 700hp and 400+tq, never have any spinning problems.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SPOOLINmatt &raquo;</TD></TR><TR><TD CLASS="quote">we use 3rd gear for the main tuning and then a few last 4th gear pulls for brushing up.

this is with 700hp and 400+tq, never have any spinning problems. </TD></TR></TABLE>

yup 3rd....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by twkdCD595 &raquo;</TD></TR><TR><TD CLASS="quote">alot of people boosted dyno in 4th because of traction but also its generally been said that you want to dyno is the gear that is closest to a 1:1 ratio. other factors come into play though and ratios are not alwasy spot on to do that.</TD></TR></TABLE>

x2

 

will there be much difference in power output between 3rd and 4rd gear ??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cyber ITR &raquo;</TD></TR><TR><TD CLASS="quote">will there be much difference in power output between 3rd and 4rd gear ??</TD></TR></TABLE>

minimal. It really just depends from car to car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cyber ITR &raquo;</TD></TR><TR><TD CLASS="quote">will there be much difference in power output between 3rd and 4rd gear ??</TD></TR></TABLE>

pretty much just dyno in the gear that is closest to 1:1 ratio. i mean would you dyno in 2nd gear hell no imagine what that graph would look like ? overstated as hell.

it also makes more sense to tune in the highest gear you see at the track. for partial throttle tuning i saw slowly go through 2-4

 

on turbo cars (400+ whp) i usually see ~20whp difference from doing a 4th gear pull instead of 3rd (but once again there are variables from car to car)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted k20 &raquo;</TD></TR><TR><TD CLASS="quote">on turbo cars (400+ whp) i usually see ~20whp difference from doing a 4th gear pull instead of 3rd (but once again there are variables from car to car)</TD></TR></TABLE>

good example to point out. have you tried switching trannies on the same car just to see how far left or right your graph shifted ?

 

well even in 4th gear with an si tranny the tires are coming off the dyno wheel, maybe its time to switch trannys cause im not going to do a dyno pull in 4th gear and go like over 200 mph on the dyno LOL

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted k20 &raquo;</TD></TR><TR><TD CLASS="quote">on turbo cars (400+ whp) i usually see ~20whp difference from doing a 4th gear pull instead of 3rd (but once again there are variables from car to car)</TD></TR></TABLE>

20whp more in 4th or in 3rd ???

 

If you can get the car to stick to the rollers wouldn't it be better on the transmissions to dyno in 3rd rather than 4th on high hp cars? I've heard of alot of high hp cars breaking 4th on the dyno but never 3rd gear.