Mindrot

iTrader: (1)

I'm sure very few of the LE5 or L61 guys have toyed with high stall converters. I'm really starting to wonder if a 3500k rpm high stall will really raise the risk of a snapped axle. Granted the stock stall is 2500 i think.. Just looking for some input from some fellow autos out there.

Please note: This will be on 8-10psi from ZZP's turbo kit.

Chevycobaltss3

iTrader: (2)

Depends on whatyou want your final rev to be and how your setup is. If i were you i would have went farther down like to a 1800-2000 rev...

Mindrot

iTrader: (1)

Well the idea is to build boost quickly using a higher stall such as 3500.. Why would you suggest 2000? Outside of the obvious being easier on axles, etc..

Chevycobaltss3

iTrader: (2)

Well concept is powerband and ect. What is your spooltime and ect. thats the kep point so say if you full spool at 2500, keep the stall 2500 for the powerband.. Having a higher stall is just something most race cars do. In orderto get the key tq power. So spool is what your wanting . do 200-300rps less then full spool!

Mindrot

iTrader: (1)

You made a good point and I'm gonna rethink a few things. I appreciate your input.

Chevycobaltss3

iTrader: (2)

Your welcome.. Keep this thread posted up of results!!

Mindrot

iTrader: (1)

I will definitely post results. Tim and everyone else has been very helpful over at ZZP

Chevycobaltss3

iTrader: (2)

Good!!! Thanks!!

newt

iTrader: (2)

While that is true, a 3500 stall would still be better IMO.

No matter what the engine make more power at 3500 than 2500, and if your ever WOT there is a 99% chance you won't be under 3500.

If you can footbreak spool the engine at 3500, then I would 100% get a 3500 stall.

I wouldn't worry about breaking axles, preload off the line with the footbrake.

Generally speaking, autotrans is much easier on drivelines than a manual, since you can preload everything right to the wheels there is no shock to the driveline when you launch.

Its the shock from dropping the clutch that kills axles, well that and wheel hop.

Mindrot

iTrader: (1)

That was my original understanding.. Foot braking right now keeps steady at 2500 or so. Doesn't drop at all so I would figure a 3500 stall would do the same thing.

ronny1204

^he knows what hes talking about lol

Chevycobaltss3

iTrader: (2)

Lol well since I do this or a living and having a stall 3500 does nothing if how power band begins before 3500. The understanding of tourque converters is what most don't think about. Having a higher stall doesn't mean its fadter or slower it just means the tq curve is here.so if op spools at 2500 best bet is to have a Tq converter. Rated at 2200-2500 stall......

newt

iTrader: (2)

I understand that, but whats the point of having a 2500 stall if your never in that RPM range except for launching?

I'm not arguing with you, I'm just trying to understand...as that goes against everything I've heard about TC's.

Why wouldn't you want to launch at 3500 instead of 2500, if you can spoll the turbo on the footbreak at 3500, then you are making more HP and TQ than you would be at 2500. And if between shifts the engine never drops below 3500 then whats the point of having a 2500 stall??

Chevycobaltss3

iTrader: (2)

It's all on the spooland when his car fully spoils.now if he full spools at 3500 more power to it.

CordiaDOHC

iTrader: (2)

In this case im still in the belief that a higher rpm stall will help especially with shifting in the higher rpms as the 4t45s have the same problem as the 700r4 and 4l60s they tend to fall on their face in 3rd gear. A stall helps with that. My camaro has a 3600 rpm stall with a 70mm turbo and it feels like its always ready to take off with no waiting on the turbo.

Chevycobaltss3

iTrader: (2)

This is peoples beleifs of stall converters. They think the higher rpm or even a rpm of 3500 is best no mstter what.

In all honesty what matters is his Tq curve and the fact of his car will be losing power by 7k. So a higger stall truly isnt recommended unless his spool and Tq curve starts a little before 3500... Reason why the v8 has the higher stall is where is the tq curve ? Around 3500 or possibly a tad before......

nhanson

iTrader: (1)

id say maybe a 3k would be good.

i wouldnt worry about snapping axles unless you wheel hop

OttawaMark

iTrader: (3)

I was talking with Jeff at EP and he says lower, 2500 but that is for my SC setup. I'd like the ZZP 245mm 3000 stall, simply because it has the furnace braised fins which the 2500s do not but I'm not sure if the trade off is worth it for the sake of some braised fins. I'd appreciate any thoughts guys.

Chevycobaltss3

iTrader: (2)

With a sc setup you want a lower stall rpm due to the Tq powerband of the Eco... It's much raiser having a lower stall and a end rev at 6800-7000 then a 3500 and not get Ure full potential of the Tq that Ure putting out.. the 3000 zzp stall i doubt is worth the justice. So is go with a 2500-2800 stall and have Ure tunert have Ure final rev at 6800-7k.... .