2nd gear launch

[LWATSON]

I've got a really tight converter and struggle to get a decent launch. The best I've got with my new charger, S475 is a 1.8X With my stock charger I could easily get low to mid 1.7s and had to be careful not to lose traction. With the tires I have now I would have been in the 1.6s with the stock charger. I feel like I'm leaving a couple tenths on the table now. I've heard its easier to build boost with a 2nd gear launch but It seems to me this would be very hard on the converter, just looking input-advise. I'm not ruling out a converter swap I just hate to do it just for drag racing, my converter does everything else fine.

 

[Hot COCOAL]

I am a newb. So take this with a grain, i have seen devices that will dial in exactly the fuel needed for a perfect launch. not sure, but i remember it being called a mixture control device. Mounts in the cab it is basically a knob that you control feul supply with from the cab, that works instantly. Not sure if this helped or just sounded dumb to y'all. Also just tryin to get ten posts so i can start an album in my profile.

 

[LWATSON]

Thanks for the help but the mixture control adjustment wont help my issue. I have a really tight converter and a large single turbo. Bad combo for drag racing!

 

[TheBac]

IMO, not much you can do other than to swap out to a looser converter. Which one are you running now? ML?

 

[ecc_33]

you'll end up buring up clutches starting in 2nd gear 4hi drag racing! It does work but not for long lol.

 

[Hot COCOAL]

In this situation if you were to add a twin and tuning, would the converter still be a problem, is a higher stall speed necessary to hook up @ launch with a high hp diesel?

Signed- lost but learning

 

[paint94979]

In this situation if you were to add a twin and tuning, would the converter still be a problem, is a higher stall speed necessary to hook up @ launch with a high hp diesel?

Signed- lost but learning

We need RPM to spool these giant turbos... a loose converter or lots of fuel(heat) will work. He cannot build enough boost on the line resulting in leaving "under" the charger

 

[LWATSON]

IMO, not much you can do other than to swap out to a looser converter. Which one are you running now? ML?

I'm running a Suncoast 1057 now, havn't decided what to swap to. Lots of options out there now. The 1057 was awesome with the stock charger but it does not like this big charger. Even with the loss on my 60' I've still ran 2 tenths quicker in the 1/8th and trap has gone up about 4 mph in the 1/8th.

 

[LWATSON]

We need RPM to spool these giant turbos... a loose converter or lots of fuel(heat) will work. He cannot build enough boost on the line resulting in leaving "under" the charger

You mention "heat", I've found if I bring RPM'S up to about 1500* and sit there until I get EGT's to 800-900 boost does come up some but not enough. I remember the old days when I would launch and my little cubby hole in the roof would empty when I launched sending nail clippers, pocket knife and dental floss to the back seat

 

[LBZrcks]

FWIW, my ML would spool the 72 I had fairly easy. How's your maf re-scaled in your tune?

 

[ripmf666]

I ran the 1055 when I had the GT4202R on the truck. Drove it for a DD but started to suck once we moved to Kansas and had to make the drive back to Maryland to many times.

 

[LWATSON]

FWIW, my ML would spool the 72 I had fairly easy. How's your maf re-scaled in your tune?

I dont know about my maf scaling, it should be good, I've had tunes from two top tuners one you know well.

 

[TheBac]

I dont know about my maf scaling, it should be good, I've had tunes from two top tuners one you know well.

If thats the case, maybe give your current guy a call, explain whats happening. See if there is something in the tune that isnt quite right for your combination. Worth a try.

 

[LWATSON]

I feel I've worn out my welcome with him. He sent me some good tunes, I logged them and he made some minor adjustments to get the power up. I sent him the third log for some final tweeks and he hasn't replied. I feel I got my moneys worth but my truck is simply not where it has been on power, but driveability and mileage is great.

 

[The Funk]

I had good luck with a 1057 and a s475 and had my fastest times on it until last night...usually left around 20-25 on that converter f the Trans was cool it would walk through the breaks until it got warm

 

[DMAXchris]

You shouldn't try a second gear launch if there's a lot of miles on the converter. It's very hard on them in 4hi from what I understand. A converter swap might be a better option than risking the TC coming apart and wiping the trans out.

 

[Dirtymaxx03]

What about talking with your tuner and seeing if he could retard the timing anymore through your staging rpms? Might be able to get a little more heat while you're spooling. I also have a really tight converter and a big single but I'm not a huge racer. I will say my truck is constantly under the charger unless I can catch a rowdy downshift at 50mph. Then it's like a rocket.

 

[LWATSON]

I got lots of miles. Around 170k on this trans and converter. I'm going to give it a couple more trys at the track and see what I can do, I may try sitting a few more seconds and build even more heat, maybe 1000-1100* and see what happens.

 

[LWATSON]

What about talking with your tuner and seeing if he could retard the timing anymore through your staging rpms? Might be able to get a little more heat while you're spooling. I also have a really tight converter and a big single but I'm not a huge racer. I will say my truck is constantly under the charger unless I can catch a rowdy downshift at 50mph. Then it's like a rocket.

I pretty much on my own now as far as tuning goes unless I buy from someone else and try again, and thats getting expensive. I've kind of got myself in a pickle with tuning. My first tunes were very strong, good for the track, but didnt shift the best in the world. I had tie ups. I bought tuning from another tuner and now I have a great shifting trans and great mileage but my truck is no stronger than it was with the stock turbo. I didn't have my stock tune to send my new tuner so now I have two different OS's so I have to do a full flash to switch back and fourth. I guess just poor planning on my part.

 

[Dirtymaxx03]

I pretty much on my own now as far as tuning goes unless I buy from someone else and try again, and thats getting expensive. I've kind of got myself in a pickle with tuning. My first tunes were very strong, good for the track, but didnt shift the best in the world. I had tie ups. I bought tuning from another tuner and now I have a great shifting trans and great mileage but my truck is no stronger than it was with the stock turbo. I didn't have my stock tune to send my new tuner so now I have two different OS's so I have to do a full flash to switch back and fourth. I guess just poor planning on my part.

That is a pickle man. I know there is several tuners that can send you a stock tune with the correct OS for your truck. Then at least you have something to start with if you decided to give another tuner a try. who has done your tuning in the past?