High stall torque converter and stock 2.5

[shackwrrr]

Does anyone else run a high stall converter behind their pretty much stock 2.5? My van has a NAN converter that the previous owner installed and its driving me absolutely insane, draining my wallet too. This converter stalls at 4200 RPM and just makes climbing any hill slow and buzzy. Under normal driving conditions I never see less than 3000 rpm and my MPG is a little less than 15. When the transmission shifts the converter swallows up the shift and there is absolutely no drop in RPM, just a quick jolt and an exhaust note change. Under WOT it instantly shoots to 4200 RPM and stays there until the speed increases enough for the rpm to climb to 5K then it shifts, it's like driving a CVT. Also since it stalls so high, part throttle builds boost so fast is surges so its either stay out of boost or give it full throttle.

My theory on why it sucks so bad is because the converter stalls so much higher than torque peak, is that why? If not then why is it so sluggish?

I have a spare 5 speed, just need a clutch and everything else.

[turbovanman²]

The converter isn't matched to the powerband, IE a fast spooling Garrett, so your running higher than needed rpm. I ran a high stall for a few years with my GT turbo and hated it, it was lazy until around 4500 then it took off. First time I drove it with the high stall I thought something was wrong until I figured it out. The reason its sluggish is the converter is slipping/not stalling/wasting fluid motion. I switched to a Hugh's 3K stall with LU for the highway and so much better but honestly, I figured my MPG would change drastically and I picked up a whopping 1-1.5 mpg. IF you want a van that is good on gas, a 4 speed auto or 5 speed manual is the only way to go.

[shackwrrr]

That's what I figured. I've always wanted a 5 speed in it but figured auto would be a pleasant change. Now just to get my Isuzu back on the road so I can pull the transmission in the van. Then the auto will be for sale.

[Vigo]

My theory on why it sucks so bad is because the converter stalls so much higher than torque peak, is that why?

Its not the torque peak, it's just because it's too high of a stall period. Anything with a 4200 rpm stall converter is always going to suck on the street whether the torque peak is 1000 or 6000 rpm. About the only thing a 4000 rpm stall wouldnt suck on for street driving would be a sport bike, but then you'd have a sportbike with an auto trans which is automatic fail, so fail noone has ever even built one. So basically someone really goofed on converter choice and you are paying for it.

[turbovanman²]

High stalls work great if you have a high powerband or large turbo.

[shackwrrr]

And I have a tiny turbo and a really short powerband. Anyone want a 4200 stall converter? (should stall less on a car) Its a NAN.

[turbovanman²]

Your basically in your max powerband when it starts to stall.

[Johnny]

ME TOO!
I ordered and Hughs converter for my black van. Got it finished yesterday (Installing the engine and trans with this converter)
It stalls around 4100 also. I asked for something for a daily driver...this sucks.

[shackwrrr]

Makes driving it a real drag doesn't it, especially on hills? maybe since you just got it they will cut it open and lower the stall for free/cheap. Im looking more and more into a 5 speed swap just can't since it's my only daily driver. Its bad when a 4 cyl van gets worse fuel mileage than a 4x4 v8 truck.

[Johnny]

Bought it 3 months ago, finally just installed it.

---------- Post added at 08:44 PM ---------- Previous post was at 08:44 PM ----------

Took it on a 450 mile trip today....got 17-19 miles per gallon.

[turbovanman²]

There's a one year warranty. Funny, my Hugh's stalls around 3500, its awesome but the lock up failed so they are fixing it.

I wish I got 17-19mpg,

[black86glhs]

What stall speed do we think would work better? 3000 rpm, 3200 rpm, 2700 rpm?

[Johnny]

Whats stock????

I'd am guessing around 3000 for a daily driver, as if yours is like mine, it cruises down the freeway at 3000 and seems like it should not be slipping then.

[turbovanman²]

What stall speed do we think would work better? 3000 rpm, 3200 rpm, 2700 rpm?

Stock is always a good starting point, but when I had Hugh's do mine thru TU, they said a 3000 stall, it was awesome around town but did slip too much on the highway, hence why I like the LU feature. That's the trouble with converters, you have to pick a happy medium. If you never care about the the track or brake torquing it for spool, the Neon converter rocks, it also has a factory bearing. I used that for a few years, got my best MPG, best around town driving but couldn't spool the large turbo at the track. For a stock type turbo, that would rock

Whats stock????

I'd am guessing around 3000 for a daily driver, as if yours is like mine, it cruises down the freeway at 3000 and seems like it should not be slipping then.

Stock is 3500 ish, but also because its not a performance converter, its a pretty tight unit.

[Vigo]

High stalls work great if you have a high powerband or large turbo.

Works great for drag racing. 4200 stall sucks on the street no matter WHAT it's attached to. Ive done 3300-3500 in the past and that was the point where i thought i was about hitting my limit. I also think the stock turbo converters are borderline too loose. My opinion is 3000 is a number that wont bother anyone on these motors.

[wallace]

Why not take a stock turbo converter and send it to a reputable converter ship to go through it. I'm using a stock turbo converter in my dd and I love it. I get 24-25 mpg.

[wheming]

I've got a PTC converter going in Mean Mini when I install the rebuilt engine and trans. Its from FM.
Hopefully it works well. Converters are a bit of voodoo, and you never really know what you get until you run it.
Slug has a Dynamic Converters unit that was about a 3000. And it was recently rebuilt back to its as purchased specs. That converter had been in Slug at least 13-15 years.

[turbovanman²]

Why not take a stock turbo converter and send it to a reputable converter ship to go through it. I'm using a stock turbo converter in my dd and I love it. I get 24-25 mpg.

You can do that but it usually costs quite a bit when there are company's that can build you one for the same or a bit less, IE Nan, Hugh's, PTC etc.

What DD?

[wallace]

the dd is a 87 chrysler T&C wagon I bought it with 79,000 on it. I went through the transmission and added extra clutch and the recommended mod's for shift improvement. Re-used the stock converter. It's got .60/.63 garrett and boost button 2 bar cal, 3" exhaust, etc. I love driving this thing it has surprised quite a few unsuspecting vitims. What I'm getting at is it sounds like when you order one from the companies mentioned it sounds hit or miss. If you send a custom converter shop your stocker and have them disassemble and upgrade it you probably won't be too much further in the hole than you would buying, installing, find out it's wrong, removing, shipping, "free" re-stall, wait for return shipment, re-install and cross fingers it's right the 2nd time around. I like the idea of using a smaller shop since you usually talk to the guy that's actually doing the work. In most cases they will call you after they get your stuff and give you an assessment of what you can expect when they are done with it as well as options after they've seen what you actually have.

[turbovanman²]

Nice. Agreed. When I send the converter back, I am going to see if they can tighten it up a tad, and also agree with Vigo, the stocker is a tad too loose. For a stockish combo or a small quick spooling turbo, the Neon converter can't be beat. If/when I build another van for the wife, it will get a decent turbo but nothing huge like mine and a Neon converter.