98 camaro w/turbo 400

[minytrker]

I have to tune a 98 with a turbo 400 in it. What all will I need to do differnt sinceit has a non computer tranny and no vss, speed refrence, or gear indication signal for the pcm. I figured just flash it to a manual and turn off all codes for tranny related items, but what else?

[VT LS1 NZ]

I’m sure you already have the Trans installed but for those contemplating the swap this is what I did.
The original Trans has 6 bolts whereas the Turbo 400 only 5.I welded an extra lug to the bell housing this isn’t really necessary but I did it anyway.
The strength that is needed is the side way force to counter this I added longer locating Dowel pins so that they protruded right thru the bell housing.

If you’re running an electronic Speedo then you need an electronic speed sensor & rotor
Here’s a link where you can pick one up: (GM part no’s 8655315 & 8655291)

http://www.transmissioncenter.net/350_or_400_high_performance.htm


Just be aware when installing speed sensor wiring they say polarity doesn’t matter but it does otherwise it won’t work.

I changed my flex plate but that was only for added strength.
To run the Turbo 350/400 torque converter you need a longer snout on the end of the converter so it locates in the crank. I’m lucky I have a lathe so I turned one up and welded to my converter then I had my converter shop do their magic & balance it.

As far as gear selection the turbo 400 shaft is smaller than the 4L60e so I turned up a longer shaft so I could still run the gear selection module this was easier than having to cut the wires and install an inhibiter switch & reversing light. Im not sure on your linkage set up but for a Holden I moved the linkage arm down slightly so when I shift gear from inside the car they all line up .The only one that doesn’t quite line up is when manually shifting second its between 2nd & 3rd not a biggie.
I added a Gear Vendor to give me my overdrive back.

As mine is a boosted application I originally ran a cable operated modulator but have changed back too a vacuum modulator because at low throttle position when I was in boost the cable modulator still wasn’t supplying full line pressure least I know when there’s no vacuum now I have full line pressure. I also modified my modulator valve weights & springs in my Trans so it shifts when I want it to. This was necessary because I still wanted Automatic shifting so the wife could still drive the car.
Otherwise depending on cam a manual valve body would be the way to go.

And of cause rear trans mounting & drive shaft modifications .Drop me a line if you have a Holden & want to know.

Now to the PCM I have run an Auto operating system with all the Transmission DTC’s turned off(the car will start if you don’t turn them off but its in limp mode and will not rev) and a manual operating system with the Auto speedometer setting programmed in the speedometer calibration(H0101).
Both scenarios worked for me above thou at present I am running a manual operating system.

Hope this helps out.Pretty simple really now its time for a

[Doc]

Nice setup. How many 4L60e's did you go thru before you made the change?

[VT LS1 NZ]

Nice setup. How many 4L60e's did you go thru before you made the change?

I built my 4l60e with the best gear around but it didn't last long its that 3 to 4 clutch pack spent in excess of $2000 on parts.Thats all I was distroying.
So I had it built again this time I added some very heavy springs to that clutch pack as under centrifugal load they start to come apart well you guessed didn't last much longer so I had it fully reconditioned again and now it sits on my workshop floor waiting for someone to take it off my hands.

I thought about a 4l80e but didn't like the overdrive up the front I think heat might be a concern.

No more problems now with the Turbo 400 & Gear Vendor.Its been a couple of years.
I'm running an external cooler & fan with Castrol Transmax Z fluid temp stays in 82 to 89'C .

[minytrker]

I have the 400 in the car already. I just started working on the tune. It has a 6.0 with a 90/90 setup. So far I cant get the car to start without holding down the gas pedal. I can get it to idle but once you put it in gear it will die unless you hold the gas a little. With no tranny input does the pcm always thing the car is in park 100% of the time?

[VT LS1 NZ]

I have the 400 in the car already. I just started working on the tune. It has a 6.0 with a 90/90 setup. So far I cant get the car to start without holding down the gas pedal. I can get it to idle but once you put it in gear it will die unless you hold the gas a little. With no tranny input does the pcm always thing the car is in park 100% of the time?

No I don't think that's your problem.Car should run without speed sensor or gear selector input.

Any DTC codes?
Got an air leak?

I always look at things logically.Re trace your steps.
Was the car running ok before trans upgrade?

Have you followed my sets above as far as PCM reprogram.

Now its a while since I did mine but mine fired up from memory and did idle.I just made some alterations to the airflow tables & idle speed.
I ran it on my original 4l60eAuto tune with the approriate DTC's turned off.When I was happy with that I upgraded to COS Manual.

[minytrker]

I know it will run with a vss, Im just wondering how the pcm see's the car, in park all the time? The idle and not running doesnt have anything to do with the tranny. Its a whole new drivetrain so it has never been run before with this motor or tranny. I have just never messed with a 408 before. Im guessing I just need to reduce the ve table down low and add timing at idle and it should run. Im going to mess with it today some more.