Auto vs Manual for a "go fast" truck

Croatan_Kid

Croatan_Kid

How's your hammer hangin'?
Joined
Nov 4, 2007
Location
New Bern
I've been planning out a project in my mind for a while now and I just can't decide if I want to run an automatic or a 5/6 speed.

It'll be my 85 S10. Currently, it's a 2.5/4speed setup. I have the 4.8 out of my Silverado and it'll get rod bolts, the top ring gapped, head studs, and maybe some head work. Then, of course, a big ol' custom ground turbo cam, and a turbo. I'll probably run 20 lbs +. It won't be a drag truck, per se, but I may run it a few times. I'll mostly just be driving it like I do the rest of my stuff.

I want a manual because they're easier, less likely to fail, I like to shift gears, the truck is already set up for a manual, and the only big wear item is the clutch. However, the auto is...well...automatic. I can also do awesome boosted launches with an automatic. A good torque converter does usually cost close to twice what a good clutch does though and then you have to factor the transmission in when you're tuning and the initial cost of building an automatic to hold as much power as I will be making will be quite pricey.

I'm basically building a sleeper, street truck. It's a plain, faded, ratty old S10 that was free and has 263k miles on it. The motor was free, not going to cost much to get where I want it, gunna run a narrowed 8.8 most likely, and see what it will do.


Opinions?
 
Croatan_Kid said:
I want a manual because they're easier, less likely to fail, I like to shift gears, the truck is already set up for a manual, and the only big wear item is the clutch. However, the auto is...well...automatic. I can also do awesome boosted launches with an automatic. A good torque converter does usually cost close to twice what a good clutch does though and then you have to factor the transmission in when you're tuning and the initial cost of building an automatic to hold as much power as I will be making will be quite pricey.

I'm basically building a sleeper, street truck. It's a plain, faded, ratty old S10 that was free and has 263k miles on it. The motor was free, not going to cost much to get where I want it, gunna run a narrowed 8.8 most likely, and see what it will do.


Opinions?
Click to expand...

So you're wanting to build the hot rod mag boosted ls and put it into an s10. To begin with, not to sound like a dick but literally everything said above about a manual being easier, less likely to fail (we're talking behind 900+hp drag truck) and clutch being cheaper than a converter (youre not running a lockup converter in a drag truck either) is entirely incorrect. Boosted launches with a 2 step and manual trans are as easy as with an auto. 900hp gm auto trans is cheap compared to a 900hp anything manual trans. It all comes down to what you enjoy driving, but unless possibly youre talking about a lenco...the auto will always be faster and it will always be easier on all drivetrain parts including the engine.
 
How about an auto with a manual vb.
 
TH400, 3500rpm stall or similar based off cam specs, manual valve body, trans brake.

Only way to go with a "go fast" truck. You'll make a little less power through an auto, but they're 1000x more consistant.

Now if you wanted a "fun to drive street truck", a Magnum T-56 with a nice twin disc may be an option.
 
auto, same rules apply here as in the case of a diesel. you just cant shift fast enough to be fun at the strip

If I were doing this, I'd get a 6l80e and a paddle/toggle shifter setup.
 
If money wasn't a factor, the TCI 6-speed auto is the way to go for a street driven "go fast" truck. 4L60E just can't hold much power. Been there, replaced that. 4L80's are MUCH stronger, but still no comparison to a TH350 or 400, besides OD that is lol.
 
RPM Built TR6060 if you have to go manual. A magnum T56 isnt a bad choice either, but if I was to be spending the money I'd sink it into the 6060.
Built 4L80e if you want to go auto.
 
Forgot to mention, gotta keep overdrive, hence the decision to go 4L80E and not just run a 400. I will definitely be running a lockup converter as well.

I had been leaning towards an automatic for a while, but I just really like manuals. However, I think it'd be easier in this case to go auto. T56s aren't cheap and if I make enough power to need a dual disc clutch, that won't be either.

We're only talking 650 to the wheels most likely.
 
An ls is gonna make alot more than 650 to the wheels on 20+psi even a 4.8 ill see if i can find a copy of the dyno sheet i had for the regal but it made 760 on 12psi through an lq4 and 4l80. But back to your question go auto for sure
 
I know of a couple guys running 20+lbs on 4.8's that are running stock 4l80e's with transgo shift kit and a billet triple disk converter form circle d. These guys are running low 10's to high 9's in fox body's. Zero problems. Another thing to look at that just recently was proven was a cheap transbrake. Just google "sloppy transbrake".

P.S. If you search how he sets up transmission shifts, it would be really simple and stout for the street. All this through the stock computer.
 
auto and transbrake. if you have never felt a launch from a transbrake on a good preped track you haven't lived. you might want to go ahead and go with a 9 inch to start with.that 8.8 aint going to last long behind 900 hp.
 
Auto. A stick is fun but as someone said, you can't consistently shift as fast as an auto. No boost loss between shifts either. Big boost coming on through a built auto feels like its melting your face off. Lots of fun
 
I'll probably just pony up and go for a bolt in 9" housing to start with. Since S10s are so popular, you can buy a housing/brake/axle package and just build a 3rd member to suit your needs and bolt it under the truck. More initial cost, but it'll be all said and done. I'm guessing I'll go with 3.73s and a tire around 28" or so. Chances are I'll ride around on 295/50-15s and get some 28" slicks or drag radials. I can easily change tunes to accommodate tire size as well.

I'm going to go with a mild 4L80E with a good triple disc converter. I've seen many people do it and run them for a LONG time. It'll get good clutches and some valve body work, but nothing extreme unless I tear it up.

So far, I've got the 4.8, a stock TBSS intake, gunna pick up a 92mm throttle body for it, I've got some 60lb injectors in the shop, but it'll probably need 80s eventually. I may or may not put bearings in the bottom end. The motor always ran great and never had single issue when it was still in my Silverado. It'll get ARP rod bolts. I'll probably pull the heads to clean them up and swap the valve springs and chances are they won't get any work done to them. Of course, it'll get a cam...maybe new lifters. Definitely push rods, springs, seats, seals, and locks. I figure I might as well go ahead and do head studs and not worry about them later. I'll also need to get a 2 or 3 bar MAP.

I still haven't decided what turbo I'll pick up. I have a 67mm Holset laying out in the shop, but I'm thinking that it won't quite be up to the job I'm going to give it. From everything I've read, I'll need something like a 74-76mm.

I'm going to make some kind of long tubes fit with the SAS in my Silverado, so I'll have some JBA stainless shorties off of that I could use or a set of stock truck manifolds. I'll fab up the exhaust and mount the turbo in the passenger's side front behind the head light.

Haven't decided if I'll run an intercooler or not. Most likely I will to keep IATs down and try my best to avoid running water/meth. I want to keep it a fairly low budget build.

There will be some sort of fuel cell in the bed and the battery will be in the back somewhere as well.


This is going to be a somewhat slow build, but simple and fairly easy to do. It'll give me something to pull in the garage and work on once my house (or whatever I wind up doing) gets done. It'll be nice to build something 2wd for a change.

I'm also planning to use a truck style PCM and have a harness made to suit that. To me, it's a fairly simple way to go about tuning and I already have an extra PCM laying around as well. I don't see much of a need to go with a MegaSquirt/MSD setup.
 
Croatan_Kid said:
I still haven't decided what turbo I'll pick up. I have a 67mm Holset laying out in the shop, but I'm thinking that it won't quite be up to the job I'm going to give it. From everything I've read, I'll need something like a 74-76mm.
Click to expand...

I'd shoot for an airwerks S400 framed charger, or a garrett GT series. You can get a Box unit S475 for $750 or so
 
That's what I was thinking. S475 probably.
 
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