So my swap is just about complete, I currently have the isuzu 5 speed hooked up. I have been reading a lot about how the isuzu isn't going to hold up for long? Well I have a spare isuzu for when that one goes, and a spare 4 speed for when that one goes. How bad is the isuzu when hooked to a V8, and what fiero tranny would I ideally want for this? I don't plan to drive like a complete moron, but I do plan to step on it every now and then. I didn't swap the motor for nothing....

quote Originally posted by V8IndyProject: So my swap is just about complete, I currently have the isuzu 5 speed hooked up. I have been reading a lot about how the isuzu isn't going to hold up for long? Well I have a spare isuzu for when that one goes, and a spare 4 speed for when that one goes. How bad is the isuzu when hooked to a V8, and what fiero tranny would I ideally want for this? I don't plan to drive like a complete moron, but I do plan to step on it every now and then. I didn't swap the motor for nothing....

F23

I have a Getrag five speed hooked up to the ZZ4 SBC in my IMSA. I don't push it in first gear. Best transmission is a poor question for everyone has a different opinion on what is the "best".

If you are a drag racer, you need a different transmission than a road racer or a street racer or use the car as a cruiser.

The "best" transmission means different things to different people. If you're sticking with a manual box in a transverse orientation, then the least expensive and least durable would probably be the two differently geared '84 four speeds, and the '85 - '88 five speed Isuzus.

Next up in terms of cost and durability are probably the Muncie 4 speeds from the V6 cars between '85 - '86.5, and the Muncie Getrag 5 speeds from '86.5 - '88 GT's. The Getrags from FWD cars like the Beretta also fall into this category, except they're a little more expensive to install because of the aftermarket bracketry needed.

Finally, in the most expensive and arguably the most durable class, you'll find the F23, the six speed F40 (from the Pontiac G6), and the five speed from the Acura NSX.

None of these transmissions are ideally geared for the low end torque, low revving nature of a SBC, although there are some that are better than others. You'll need to set your own priorities between the cost, durability, gear ratios, and technical difficulty to install each one. In my own case, I built a SBC car that I've been running for the last 15 years with the same Isuzu tranny in it all along. You'll be fine with your Isuzu as well provided it isn't a worn out transmission in the first place, and that you stay away from 3000 RPM drop-clutch starts. Although I'm happy with the Isuzu, my latest project car has an F40 because this transmission was factory rated to 300 lbft of torque, the best bang for the buck when compared to say the Getrag or the Isuzu (~250 lbft and ~180 lbft respectively, IIRC).

My 86 had an Isuzu in it, so I used that for my 350 swap. The car had 166,000 miles, now almost 170,000. I have no way of knowing if this is the original trans. or not. It works fine , but low is really low, and everyone says don't abuse second. I do have two spares, one was $40 and the other with a good 4cyl motor was $60. Cruising is the good thing about the Isuzu with the low numerical overall final drive. If you get on it a lot and shock the transmission, I doubt it will last very long. As guys have mentioned, there are better gear boxes, just not cheaper!

Alright, thanks guys. So If my '86 isuzu does explode, would I be better off replacing it with an '88 isuzu, or putting the '84 four speed in? Also, what is the F23, I've never heard of that?

If you are thinking about using the F23 with an Archie SBC kit, you will have an interference issue between the axle seal protrusion on the passenger side of the F23 and the 153 tooth ring gear used with the Archie swap. You will either need to machine down the flywheel to either accept the 148 (still might not clear) or the 142 tooth ring gears for the needed clearance, but then you also have to rework the starter mounting area and get the needed room to push the starter up that tight to the block. It will probably require reworking the oil bypass setup as well to something even more compact. Once you get all of those things done, then you need to deal with the HTOB and the Archie flywheel being about .200 inches further away from the HTOB than the stock application.

The F23 really isn't a bolt in mod for the SBC that people think it is.

If you are using a Zumalt style adapter, then it shouldn't be any more difficult than adapting it to any other fiero engine.

quote Originally posted by V8IndyProject: So If my '86 isuzu does explode, would I be better off replacing it with an '88 isuzu, or putting the '84 four speed in?

That would depend on whether your '84 four speed has the "econo" gears (axle ratio = 3.32, final drive = 2.42:1) or "standard" gears (axle ratio = 4.10, final drive = 3.32:1), and whether or not you were looking for quicker acceleration or better mileage. Then there's the appeal of a five speed over a four speed, more wear vs less wear, etc. If it were my choice though, I'd stick with the '88 Isuzu and avoid the 4.10 axle ratio four speed. At highway speeds, you (and more importantly your girlfriend/wife) will find the engine revs and noise hard to take over anything more than an hour or so.

quote Originally posted by V8IndyProject: Also, what is the F23, I've never heard of that?

It's a well built five speed transmission used on cars such as the 2000 - 2002 Cavaliers.

I went through several isuzu's on my 4.9 !!! ..... finally found a getrag at the junkyard 3 years ago ... no problems since

I sure wish there was a cost effective way to control a 4t65eHD with a SBC carb setup..... The controller packages are still to expensive to jusitfy me going this route. Is there anyone that has a carb SBC that is running a computer controlled transmission?

quote Originally posted by diabloroadster: I sure wish there was a cost effective way to control a 4t65eHD with a SBC carb setup..... The controller packages are still to expensive to jusitfy me going this route. Is there anyone that has a carb SBC that is running a computer controlled transmission?

Actually if you don't mind shiftng a couple of toggle switches it can be done without a PCM. I do it on my 3800 cuz I couldn't get it to shift on it's own with a lower gear change.

quote Originally posted by Dementia: Actually if you don't mind shiftng a couple of toggle switches it can be done without a PCM. I do it on my 3800 cuz I couldn't get it to shift on it's own with a lower gear change.

You never got that figured out? What gears where not shifting right?

Not to steal the thread but, I never could get the WOT shift points to work at all. Tried everyones suggestions to no avail. Shifted smooth and worked great at all other settings. Checked continuity on all trans wires to PCM and all appears ok. It's not that bad using 2 toggles n I shift when i want.

https://www.fiero.nl/forum/A...110502-2-105101.html I put this together to run my 65e. I don't have line pressure control but it does the up/down shifting and disengages the tcc when shifting. Line pressure is maxed out but I've learned to drive with it and nobody would notice if I didn't tell them.

Here is the current setup. I use a cadillac shifter with tap shift and had to use relays and diodes to run the 7 segment display because I didn't have enough outputs. There is a super relay that has pwm and more outputs but didn't look into it. It probably still cost around $300 with the shifter.

I looked at your thread- very interesting!

I also looked up: http://e-transcontrol.com/magnashift.htm that was mentioned in that thread, I think Im going to buy one of those controller packages. I was planning on swaping out my sbc with a 3800sc just because I want a automatic - those controllers are alot more affordable than the other ones I have seen. I can get a good 4t65eHD for $200.00 with the converter, the top of the line controller package there is $575.00, figure in some c/v axles and other misc stuff I can swap in a 4t65eHD for around $1000.00 or so. I cant even find a decent 3800sc and trans for less than $1000.00, so I can keep my freshly built sbc thats gotta have around 375 hp and save alot of work and money instead of a swapping in a 3800sc with less power..... Wow- I feel good!

I have an Archie adapter and flex plate for a sbc to 4t65e hd. I bought it before I decided to go ls4. Cost me $600 and I would like to unload it. Ryan Hess made a tap shift controller for the 4t80e for $200. I bought one from him that we were going to try on my 4t65e hd and N* swap. I think that he is making one now that has a manual automatic option. If you don't mind an automatic the 4t65e hd is the strongest thing you can do and they can be built to handle anything you can fit into a fiero.