Fiero 2m8 LT1 NX Roadster conversion (Page 7/46)
Fiero2m8 MAY 16, 07:46 AM
Some people have been asking about TH125c to 4T60 swaps.
Since I had both handy, I took a measurement between the axle seals on both transmissions.

The stock Fiero TH125c is 19-!/4"



While the 440T4/4T60 trans is 21-1/4"



Since the new trans is approx 2" longer, that is why you need new axle solutions.
Let me know if anyone needs any other measurements taken.
Fiero2m8 MAY 16, 01:42 PM
Maybe someone can help me hear - otherwise I might be able to ask Mark at Street and Performance:
Below are pictures of my 4 prong plug from my custom harness that ran the stock Fiero TH125c.
It has only 2 wires on it that need to be cut and married to the Cadillac 4T60 5-prong plug - Does anyone have a wiring diagram or know what the 5 wires are for, so I can splice them correctly?
This is a non Electronic 4-speed overdrive 4T60 from a 1990 STS.

Red and brown only on the custom harness / LT1 92/93 ECM



Orange, Grey, Pink, Brown, and Green on the Caddy trans to choose 2 or more from



Any educated ideas or better yet advice from experience would be a plus for you...

Fiero2m8
Brian Lamberts MAY 16, 07:19 PM
I did a start on a rag top conversion on an 84 about 10 years ago. Using standard suspension and 14 inch wheels, I had ground clearance problems with the x-frame. I'll be interested when you get it all back together with your final choice wheels--to see if you have problems with speed bumps and other road hazards. That x-frame you've installed looks massive!

[This message has been edited by Brian Lamberts (edited 05-16-2006).]

Fiero2m8 MAY 16, 08:26 PM
Thanks Brian - I've read many of your yahoo email posts and trust your judgement, so l'll watch for that and measure the ground clearance. The close up pictures do tend to make the x-frame look bigger on the thread.
Also, the car did sit much lower on the 13 and 14" stock wheels I used to have on there.
Luckily it will be for cruising friendly roads after checking the weather report
I did increase the x-frame dimensions from 2-1/4" to 2-1/2" box due to less cost and extra strength for the V8.
I guess time will tell how soon I will need to get new springs

Also on the transmission measures above, I forgot to mention that the extra 2" inches in length is on the passenger side, which is very good news for me so I can retain my custom shortened Pontiac 6000 axle on the drivers side and reuse the Fiero auto axle on the passenger side since I moved the entire assembly 2 inches to the left to make room for the LT1's water pump.

Fiero2m8

P.S. Before I put the P245/50R16 Goodyear Gatorbacks on I had Pirelli P225/60R16's on the 3-spoke rims that filled out the wheelwheels nicely, but made the car sit too high in my opinion. Since 18 ot 19" rims aren't in the budget this year, I may have to swap the other tires back on - stay tuned.

[This message has been edited by Fiero2m8 (edited 05-16-2006).]

Fiero2m8 MAY 20, 01:04 AM
Still waiting on the crank to come back from balancing, so I worked on finding a home for the other sub and the amp:

Front compartment sub box is completed:



The other sub is now mounted under passenger side dashboard:



You can see that it is relatively well hidden considering it is a 600W 10" sub:



The only place I could fit an amp this size was behind the passenger seat - not wired yet, but here it is mounted:



You can really start to get a sense of what the project will look like from the outside now before paint:



Fiero2m8
Fiero2m8 MAY 21, 12:56 PM
Yesterday I got a layer of fiberglass mat down and two layers of fiberglass cloth and resin built up on the B-pillars:



After some sanding, they will be ready for a thin layer of filler to finalize the shape.


------------------

1986 Fiero2m8 (LT1 NX / 4T60 Roadster Build)
http://www.fiero.nl/forum/Forum2/HTML/071642.html

Gokart Mozart MAY 21, 02:15 PM
One thing I was wondering, but you don't have to worry about, is why not use a double X underbody X-frame? Leave the opening for the gas tank but keeping it stiff.
Fiero2m8 MAY 21, 05:47 PM
Hey GoKart - sounds to me like that design would work good too.
I already had to try my removeable X out to drop the gas tank and it worked just fine.

Here are some updated pictures of the B-pillar bodywork - the part of the build I detest.
A lot of patience and elbow grease is required, but I got the first two layers and sanding done today.










Fiero2m8
Fiero2m8 MAY 24, 12:34 AM
Test fitting the high rise wing



Yes it is my notchback - I bet I could sell it as a wing though

I decided with the roadster to go with a spoiler over a wing, so I removed the Lumina Z34 wing shown here:



As replaced it with a spoiler off a 1986 Camaro (no 3rd brakelight in it as they were on the hatch that first year)
Wrong colour but you get the idea - it requires 6 holes and is fastened with 10mm nuts with washers:



I'm also working on side scoops that I'll post pictures of soon.

Fiero2m8

[This message has been edited by Fiero2m8 (edited 05-24-2006).]

Fiero2m8 MAY 24, 06:20 PM
Passenger side scoop installed from a 1983 Pontiac Trans AM.
The driver's side will be a little more work, but I prefer them to be the same vents on both sides, so I am going ahead with it.



Fiero2m8