SRT8 Diff Gears

[Cruzmat]

Just had my 6.1 dyno'd at 1,800 km's, with 191kw result at 212 km/hr. The guy wasn't too supprised of such a low reading after such low k's, but suggested I change the diff gears because the horseys don't kick in 'til over 200 km/hr. Anyone tried this or got any advice?

BTW had dual 3" cat backs fitted post dyno, now she sounds angry!

[glhs837]

Something is wrong there, and its not the diff gears. That number converts to 256 wheel horespower (whp), and thats ridiculously low for an SRT, you should be seeing at least 350whp, which in your terms is 261KW.

Given that hes' talking about where on the speedometer hes' reading power, and not expressing it in terms of where in the RPM band your making that power makes me leery also.


Personally, Id find another shop, I dont think this guy is really up to snuff.

[Cruzmat]

Originally Posted by glhs837

Something is wrong there, and its not the diff gears. That number converts to 256 wheel horespower (whp), and thats ridiculously low for an SRT, you should be seeing at least 350whp, which in your terms is 261KW.

Given that hes' talking about where on the speedometer hes' reading power, and not expressing it in terms of where in the RPM band your making that power makes me leery also.


Personally, Id find another shop, I dont think this guy is really up to snuff.

Thanks for your input.

Seeing 261KW would be great, but the other stock SRTs I know about in Australia are only pulling 201 - 212 KW with under 2000km on the clock(I think that's about 1200 miles). Could be due to the very strict emmission laws over here, plus the low mileage and I'm in Brisbane in the middle of summer with an ambient temp of 31C and humidity 62% on the day.

Yeah I hear what your saying re the hole rev band v's speed thing, and now I've done the cat backs and cold air ram coming next week, I'll try another dyno tuner plus the guy i've already used to get a comparison and post the results back here.

Cheers.

[Hemi57]

From memory other Aussie member's SRT8s have been recording ~240 Kw. Your figures are being affected by the tight drive train and weather conditions I reckon. Oh and also, not all Dynos record the same from what I am led to believe

[glhs837]

Yeah, those ambients are a factor, do you know what your coolant temp was during the pull? Anything over 200F (93C) is a power killer, but do have it over 180F (83C).

[Cruzmat]

Originally Posted by glhs837

Yeah, those ambients are a factor, do you know what your coolant temp was during the pull? Anything over 200F (93C) is a power killer, but do have it over 180F (83C).

Thanks for the feedback, I'm not to sure about coolant temp, it normally runs around 95C on the street, remembering it's summer and the new toy. I'll make sure to check on the post cold air ind tune!

Cheers

[MrVelvet]

with under 2k km on the clock mine ran in the 240 or so bracket on a warm day. One of the things we did note is that you have to ramp it up on the dyno very slowly because even with the TC 7 second disabled the ECU detects the slip from the dyno rollers and starts reducing torque. Took a few goes before we got it right.

Cheers
Russ