Competition Need help with 6 speed shifting technique

[TomGolden]

Hi all,



I am in serious need of some advice on shifting techniques for the strip. Last weekend I raced for the second time ever, and here are my results:



R/T: . 75 seconds

60' time: 2. 7 seconds

E/T: 16. 9 seconds (oops, I was off by a second here)

Speed: 90. 19 MPH



Oh yeah, truck weighed 7270 #'s without me in it, 1/4 tank of fuel.



We had about 8 or so TDR guys racing at the Sacramento drag strip. Airhorns Dennis from Yuba City whose truck is very similar to mine, except he has the DD 2's, Pier's SuperTurbo and an auto transmission, had an E/T of I think 14. 5 seconds at 92. XX MPH. Also from reading other people's times here and on Diesel-Central, it looks like I am running reasonably fast speeds, but considerably slower E/T's than others running similar terminal speed.



My guess is it is related to my shifting timing. So far I have not had the nerve to launch in 4WD, as there is no way I could shift back to 2WD going down the track (too busy shifting other gears!!). I launch at about 1200 - 1400 RPM in 2nd gear, and then basically wind up each gear till something like 2700 RPM, then shift. I barely get into 6th gear before the end of the 1/4.



Someone suggested I shift closer to 2000 RPM, which I tried doing my second run of the day (the stats listed above are from this second run), but the turbo lag on my stock HX40 just kills me if I shift at too low of RPM going into the next higher gear.



Oh, my new hot Comp was on 5x5 for both my runs Saturday. In case you're interested, my stats from prior races are:



In August with EZ instead of Comp:

R/T: 1. 5 seconds

60': 2. 90 sec

E/T: 17. 6 sec

MPH: 86. 9



First run Saturday: ( I missed the 4-5 shift on this run )

R/T: 1. 2 sec

60': 2. 8 sec

E/T: 17. 4 sec

MPH: 84. 5



I am actually more interested in higher terminal velocity than in E/T, but I would of course like to learn how to do it as good as I can. Based on my BOMBs, I am sure my truck is capable of 14's or even 13's with a good driver.



Thanks,

Tom

 

[CRuD]

With all those mods why not start out in 3rd?? I don't know if the clutch will handle it. On the other hand if it does one of three things will happen. 1 Agood thing is you launch off the line and do great. 2 You smoke the clutch and slip your way to the finish line. 3 You twist things apart in your drive line and have to be towed off the line by a Honda ATV 4 wheeler.



Sorry I can not help you out here. I have enough trouble trying to shift fast enough to keep my "little 6 cylinder" happy when running emtpy. I have to hook my 5er on her to make her remember that she is a truck and not a sports car.

Good luck

See Ya

Chris

 

[joesoot]

We need an aftermarket shifter. Anyone listening?

 

[Steve St.Laurent]

Tom - keep in mind that you are shifting a manual transmission, your times are not that out of line for the mph you are running with a manual. Most of us that are drag racing with manuals are doing it with 5 speeds and you have an extra gear shift in there. My best time so far is a 15. 78 with my 5 speed. I've experimented with 3rd gear launches with my 5 speed and the times were definately slower than launching in 2nd - but with your 6 speed you might be able to make it work. Remember that every time you shift you have a period of time that you're making no progress (my estimate is . 2 seconds for each shift) plus you're losing boost between each shift. Launching in 4wd seems to be good for about a full second in the 1/4 but I for one don't have the cajones to do it! You could also slam shift (leave the throttle wide open and just push in the clutch and grab the next gear) - but that too is too abusive to the drivetrain, IMO. JMHO

 

[Bad340fish]

You might try launching at a higher RPM. Maybe try about 2000 then just swap petals. Let the clutch out as you put the throttle down... . don't drop it just ya know... . let it out lol. I got a 14. 48 out of my buddies 01 3500 ETC 5 speed the other night and thats how I launched with a 2. 17 60ft. I just stay in the smoke pedal and bang the gears at about 3000. His truck has DD2s so it RPMs a little better than stock injectors.



With my truck having an EZ only I have to ride the clutch out a little longer. But I still managed a 2. 25 60ft with on a 16. 20 run. I have more traction problems hitting 3rd than I do leaving the line.

 

[Gizmo 007]

I pulled a 15. 2 run the other day with my 7300# 3500. I shift a little different than others, but it works. Might be something to try.



Start in 2nd, Rev to 2000 rpms. Ease out of the clutch and floor it at the same time (trying not to break the tires loose).

Back out to about half throttle, stomp shift to 3rd.

Floor it to about 2750-2800 rpms, stomp shift to 5th (skip 4th gear) while backing out of the throttle slightly.

Floor it to about 2700 rpms and stomp shift to 6th.



I can make it shift fairly smoothly. Skipping fourth sounds rough, but it helps my times a little. I also don't like the 4wd idea, too much stress for me.