[Katfish]

Went to the track to see what the 3.73's would do. Last time we went it starting raining and only got 2 passes in.

Temp was at least 20deg cooler (~60F), that that should help. Car went a full 1 second slower than last time. I know the 60's are slower, but would that be the whole difference. A little background:

- 8 gallons of 93 and retuned right before.
- Car threw 2 "running lean" codes right before pass in staging lane
- Seemed to run ok, shifted and pulled hard.

Only difference between this outing and last is the weather and I did add a oil seperator on the driver's side.

Stinks going from 13.7 to 14.7!

[bigstick]

Originally Posted by Katfish Went to the track to see what the 3.73's would do. Last time we went it starting raining and only got 2 passes in. Temp was at least 20deg cooler (~60F), that that should help. Car went a full 1 second slower than last time. I know the 60's are slower, but would that be the whole difference. A little background: - 8 gallons of 93 and retuned right before. - Car threw 2 "running lean" codes right before pass in staging lane - Seemed to run ok, shifted and pulled hard. Only difference between this outing and last is the weather and I did add a oil seperator on the driver's side. Stinks going from 13.7 to 14.7!

Getting rained out > That means higher humidity > slower times.

I doubt that would account for a full second though.

[Katfish]

I got rained out the last time when I went 13.7 (6 months ago in May)
It was at least 85F and HIGH humidity.

Weather was what I thought was perfect this time, ~60F & low humidity!
and best I can do is a 14.7

Last 2 passes where 14.8 because of added weight, I let my daughter ride along, she probably weighhs ~80lbs.

I can only guess the "lean code" pulled some timing and hurt the hp?

[Rich11]

It's your 60's.

[69fastback]

I don't think it's all in the 60'. The 60' is hurting you probably .5 on the ET, but you've lost 3 MPH on the trap. It's lost power somewhere. I'd check that tune out.

[DickH]

looks like most of your time is lost by the 330, did you bog after the 60ft?

[Katfish]

Didnt notice any bogging. I'll have to get some more 93octane and retry the race tune. Still thinking the error codes detuned the performance.

Car never threw a code before, maybe I got some bad gas?

[69fastback]

If its trapping slower, at the same weight, throw all the short time numbers out, because they don't matter. The car isn't making as much power. 3 MPH is significant.

[mrbigjeep]

betting it had something to do with the CEL although a 2.3 60' sure doesn't help

[DickH]

All the mph difference is there by the 1/8th, just carries through til the end of the 1/4. Problem might not be the 60ft, but it is in the first half.

[Shaun03GT]

Trapping about 3.5mph slower in the 1/8 and about 3mph in the 1/4. One of your runs with a 14.7 with a 2.1 60' the other was a 13.7 with a 2.096 60'. So theres something going on. Maybe a bad tank of gas? Do you know why it was running lean? What did you do right before you went to the track?

[onurleft]

Just by getting your 60 down to a 2.0 from a 2.3x should get you in the 14.0-14.1 area. The rest is probably due to the weather and your lean code.


Figure every .1 in your 60 is .2ths off your e.t

We had a similar experience with my friends 335. We added an LSD, went back in slightly warmer weather and it only went 13.6 compared to 13.4 without the LSD. The 60's were the about the same but the slower time was due to more humidity and more heat soak from the car

[Katfish]

Does the car need some time to "learn" the tune? I normally drive around town with the 87 tune.

Previous time at track, I filled up with 93, programmed the tune, then drove the 1hr (70 miles) to the track and ran the 13.7.

This time, I drove to the track to empty tank of the 87, put in 1/2 tank of 93, programmed the race tune, drove 5 more miles and ran the car and did a 14.7 with "lean" error codes?

[69fastback]

Your 60' can change a bunch and not affect your trap speed. The trap tells the story.

Example: on DRs, my car cut a 1.8 60' and went 12.32@121 MPH. On slicks it cut a 1.51 60' and went 11.43@121



ET shows driver. Trap speed shows power.

[Shaun03GT]

Originally Posted by 69fastback Your 60' can change a bunch and not affect your trap speed. The trap tells the story. Example: on DRs, my car cut a 1.8 60' and went 12.32@121 MPH. On slicks it cut a 1.51 60' and went 11.43@121 ET shows driver. Trap speed shows power.

Exactly, this is one of the things I preach. Even a shitty driver doesnt really affect the trap speed to much. I mean unless your terrible.

OP's trap speed is down 3.5mph in the 1/8 with almost identical 60' time, and 3mph in the 1/4. I say take off the canned tune, and run it again. See if it was just the tuner.