pwrtripls1

If I was to run my truck up to 4200rpms what will I need to do to still make power that high? Just 60# springs?

I want to spin it that high because its my only shot of making a getrag truck fast. I need to stay in each gear as long as possible.

unixcowboy

You'll need a cam....

I can tell the diff punching it at 2200 in 2nd and punching it at 3200 in 2nd.
Lots more torque at 2200 - seat-of-the-pants.

HARDTIMES

i would think you would also need a big lift pump to feed it

wannadiesel

It will spin that fast but it will make not make much power above 3k. The VE just doesn't put out the fuel at high RPM.

The best way to get good times out of a Getrag is to launch in 3rd and get to 5th quickly, use that monster torque to good advantage.

Crossy's son

Which means you'll need a REAL clutch like GLHS has to make a getrag truck run.

GLHS

You want it fast for the dragstrip?
If so, I shift around 3300 rpm with my timing set at 2.15 mm.
Sure, I could spin it higher but, as wanna stated, the power will fall off.
Once I had the timing jacked up around 2.30 mm and was having problems going into fifth so I was going across the line in 4th @ 100 mph (about 3900 rpm). Slower et's for sure. More timing will really help the rpm and lower egt's.

A Southbend FE single will last for 20-35 passes; if you don't slip it too much at 450 hp. I would go the next step better; whatever that would be that Peter makes nowadays.
My single clutch is in my sig and will hold about 600 hp.

unixcowboy

GLHS -

Looking at your sig I was wondering ---
What size are your injectors?
You just say 'custom' ...

I'm going to get a set next year - Feb or Mar - and was thinking of 6x16's.
1st I want a new turbo and I want one like you have - 62/71/14 ...

bgilbert

I was wondering when Kurt would jump in here and correct you on going fast in a stick truck.
Does it hold 4wd 3rd gear lauches? RPM? I'd like to swap out my FE for something like it myself.

Crossy's son

GLHS. are you running a 12mm h/r pump or 14mm ?

pwrtripls1

I want to be able to bolt on a set of slicks on friday night and head out to LoneStar Raceway to beat up on some mustangs and such. I would like to make it to the track 5-6 times a year at least, and run a few times each night. So can you explain this 3rd gear launch to me? I have seen vids of 2nd gen duallys doing it and they were moving. I've tried it once with my stock clutch and nothing, it wouldnt even try to hold. lol

So how do I get ahold of a clutch like the one in your sig and how does it drive on the street? I can sometimes drive several thousand miles a month so it needs to be tolerable. Can you PM me with a price on it and maybe a person to contact about ordering one?

GLHS

Autos are great for the strip; unfortunately that's about .1% of the time, for the rest I like having the stick.
I am running the 12 mm head.
The 62/71/14 is on the verge of being too big for my liking at 5200' of elavation. If it were not for the porting of the turbo and exhuast manifold, it would be worse. At your elevation you might be able to get away with a 64/71/14. If I had a cam, that's what I would run.
Injectors are DDP 5 hole extrudehoned 71 liter per minute (approx 5x15). IMHO, a 5x15, 5x16, 6x14, 6x15 or 6x16 will get what you want. No 4 hole injectors. A 6x16 is 38% larger than mine. I have heard of people running others injectors but some, not all, don't make the numbers.
Bill; the clutch is a 4 puck design. If I remember correctly, the FE's come with a 3600# diaphragm pressure plate. This one is also 3600# but waaay stiffer and has just 4 fingers. So far after about 20 passes, it feels as good as new.
Never tried a 3rd gear launch. 2nd gear only @ 3000 rpm. I let it out quickly but, do not just dump it or "side step".

GLHS

Looks like I replied while the last person was posting.
I think for a 3rd gear launch you would have to ride the clutch for at least a couple seconds before letting it out completely. If that's the case then I would recommend a quick shifting dual disk..........if that's possible. I have heard of some being made out there.
The trucks you have seen making good 3rd gear launches probably have 600+ hp.

tcs 91

i wonder what kind of pressure ddp uses to get its flow ratings? they say iv's flow 55 lpm but that would be dependent on a given pressure, right?