Been trying to find a local shop in the Buf/Roch/Syr, NY area that can do a catback install on my G sedan with before/after pulls, but that is proving a bit more difficult than I expected. Grrr. I can install but I really don't want to do this on a cold garage floor and I really, really want the before/after dynos from my own car with as little time lag as possible to help minimize variables.

In the interim, can you guys help me with: what type of dyno to use; what settings, i.e. smoothing, etc. I should be requesting for that particular machine; is it best do 6MT sedan pulls in 5th gear for 1:1? What the top speed will be hit in the session, i.e. got the 90mph rated winter skins on - I presume I'll need to bring along my stock rear wheels/tires to swap for the pulls?

You get the drift...I'm looking for any and all dyno tips to get the best/most data from the pulls. My (gasp!) 1st time on the dyno and I want to do it right. These will be my baselines for future mods. Thanks.

Greg - I am within an hour of the Buf/Roch/Syr areas. Also, thanks for offering to share the dyno sheets on BRM's catback. Is that for the G coupe, though?. I have a sedan.

ok, for dyno info.........make sure you have a wideband O2 sensor available. The ones that go in the end of the tailpipe are fine.

reset your ECU 12-24 hours before and drive hard on the way to the Dyno and the night before.

Check your airfilter for dirt, bugs, etc that may be blocking air. A K&N or other oiled type can look brand new on one side but completey black on the other, same with paper and foam filters.

Try to get at least one fillup in between now and the dyno.

Smoothing, doesn't really matter, play with the run view software and set the smoothing to your taste.

Dynojet 248 is very common, pretty much any dyno will work as long as it is not a Mustang Dyno.

5th gear is the best but some dyno's are only rated at 120 mph max, so in that case a 4th gear pull will work and oly be off <5hp.

stock wheels hmmmm........ if you have a different size wheel on or a steel wheel on with your winter tires then yes, but if the wheels are same size just different look, no you will be fine

top speed in 5th will be around 135 or 140 or so.

that 90 mph rating is "sustained" speed on perfect road conditions. I think if it is your first time on a dyno, it might be cool to see the difference between your snow tires and stock tires/wheels. anyways I probably wouldnt go above 120 or so in the snows. But that long should be ok for a few seconds.

vq - great tips, thanks. I was surprised about the ECU reset. I thought the 6MT's didn't benefit much by doing that, just the 5AT's? Make a diff between quick reset or battery disconnect? Still nervous about the tires though - winter tires are 215/60-16 on Konig alloys vs. OEM 215/55-17 on the 5 spokes. I have a seperate winter/wheel pkg so it's not a big deal to swap for the pulls. They are, however, very close

radius = 13.1" vs. 13.2"diameter = 26.2" vs. 26.3"circum = 82.2" vs. 82.7"rev/mi. = 771 vs. 767difference = -0.6% vs. 0%

I'm thinking about using this shop:

Kennedy's Dynotune 3165 Niagara Falls Blvd. North Tonawanda 14120 Tel. 716-693-5354 http://www.kennedysdynotune.com

They have a 248C Dynojet Chassis Dyno

Thanks

vq - exhaust in hand, with install and before/after dyno time scheduled for Wed 7th

What were the results on the dyno?

For DYNO results, click here.