So I'm commencing a 350 swap and have been picking up parts to do the build. The plan is for a moderately to moderately heavy built 350 that will get more or less daily use (mostly city) driving in the summer, with the occasional road trip. The set up I'm buying has an Isuzu 5 speed on it now attached to a 350. I have the option of purchasing a Getrag from a Fiero. I also looked at the F40, but it seems all that's talked about with them is using them with an LS4, which I'm not using. I've been doing some research but my eyes are practically bleeding and I'm somewhat overwhelmed, so figured I'd just throw the question out about recommendations.
Isuzu, Fiero Getrag, (insert other model) Getrag, F40..... or...... ?
I have driven SBC's with the Isuzu 5 speed, Fiero Getrag, FWD HTOB 282 Getrag, and F23 Getrag and also driven an LS4 w/ F40.
They all have their good points and bad points.
My personal favorite is the F40, but it certainly is the most difficult/costly to install, rattles at idle without the clutch pressed, and the shifting is a more clunkier than the others (the transmission shift rail assy has a gated shifter assy internally).
The F23 is popular for strength, but with the 3.94 final drive it was my least favorite to drive with a SBC. It shifts quick and smooth though.
The 282 will hold up for quite some time if you drive it like a sane person and start with either a rebuilt unit or a lower mile one. Worn differential bearings will cause the case to break when abused.
The isuzu is probably the best shifting transmission and has the lowest cruise RPM for all the 5 speeds, but they can't take much abuse before stripping the teeth off 2nd gear.
My advices is to start with whatever you have and upgrade as you break it. This will keep the initial cost of the swap lower or allow you to spend the same $$$ but get better engine parts.
I have driven SBC's with the Isuzu 5 speed, Fiero Getrag, FWD HTOB 282 Getrag, and F23 Getrag and also driven an LS4 w/ F40.
They all have their good points and bad points.
My personal favorite is the F40, but it certainly is the most difficult/costly to install, rattles at idle without the clutch pressed, and the shifting is a more clunkier than the others (the transmission shift rail assy has a gated shifter assy internally).
The F23 is popular for strength, but with the 3.94 final drive it was my least favorite to drive with a SBC. It shifts quick and smooth though.
The 282 will hold up for quite some time if you drive it like a sane person and start with either a rebuilt unit or a lower mile one. Worn differential bearings will cause the case to break when abused.
The isuzu is probably the best shifting transmission and has the lowest cruise RPM for all the 5 speeds, but they can't take much abuse before stripping the teeth off 2nd gear.
My advices is to start with whatever you have and upgrade as you break it. This will keep the initial cost of the swap lower or allow you to spend the same $$$ but get better engine parts.
IMO that's great advice. Thanks for that and the other info. I don't intend to thrash it *too* much, but I would like to humiliate the occasional backwards-hat wearing fartcanon Honda guy once in a while without leaving transmission parts in the middle of the road.
The isuzu is probably the best shifting transmission and has the lowest cruise RPM for all the 5 speeds, but they can't take much abuse before stripping the teeth off 2nd gear.
F40 ..rattles at idle without the clutch pressed .
Hmm so if you rev up 1st and take it easy on 2nd an Isuzu will work ok on a V8?
My stock getrag rattles at idle without the clutch pressed, I know of quite a few other owners who have the same issue.
I read that somewhere but couldn't really nail down what they came in.
Cobalt XFE (Extended Fuel Economy)
However, the transmissions with that gearset do not come with the V6 bellhousing pattern, so you have to buy one of the 3.63 transmissions and one of the 2.2 pushrod transmissions and make two out of one to get that gearset.
Hmm so if you rev up 1st and take it easy on 2nd an Isuzu will work ok on a V8?
My stock getrag rattles at idle without the clutch pressed, I know of quite a few other owners who have the same issue.
You can also push 5th gear out of the end of the Isuzu case at 135 mph... I ran an isuzu with a 282 whp 317 wtq SBC for a year and it didn't give up the ghost. Its OK for a cruiser and mashing the throttle in gear, but I wouldn't use it for the 1/4 mile or with sticky tires.
My intent isn't to thrash it too hard. It would be fun to crush some of the dimwits in their Mustangs, and the smartass Honda dorks with their grapefruit canons. Other than that the only possible racing I might do would be autocross. I'm planning to build the motor with that in mind (having drained the pan on the original 2.8 that was in this car on a long hard sustained right hand curve......) Radius and relieve oil returns, baffle in the oil pan, and an oil accumulator.
Regarding the 87/88 Fiero 5 speed transaxle, aka Muncie/Getrag 282 MG2. The common shortcomings that always come up when mating this transmission to a larger engine is, it was never designed to take the amount of torque the larger engine is capable of producing. (repeated off the line dumping the clutch) The alternatives usually recommended are either the Fiero Getrag 4 speed, the F-23, or the F-40. While the latter two are excellent trannie's, they involve a lot more money than the application of a little common sense and keeping the 282 5 speed.
I found these figures on gears ratios for Muncie/Getrag Fiero 5 speed transaxles. Manual Transmission Gear Ratios Year ____Style __Code Axle 1st 2nd 3rd 4th 5th rev. 1988 4cyl 5 speed MT2 3.35 3.73 2.04 1.45 1.03 0.74 3.50 1988 V6 5 speed MG2 3.61 3.50 2.05 1.38 0.94 0.72 3.41
OK, this may either sound like a dumb question or, a too good to be true question. The question is, are the final drive gear sets interchangeable? Upping the final drive ratio from 3.61 to 3.35 in the MG2 Tranny would result in approx 9% taller final drive ratio. If this is possible, why has no one done it? Like said, sounds too good to be true. For any of the common engine swaps having more than enough low end torque, it would not only offer lower rpms at highway speeds, but lessen the stresses fed back thru the drive train in the lower gears. And, if this IS possible, since I am facing a rebuild of my 282 anyway, should anyone have that 3.35 final drive gear set laying around gathering dust, I sure would be interested in taking it off your hands. Please PM me with any offers.
[This message has been edited by Monstertone (edited 02-19-2020).]
You can also push 5th gear out of the end of the Isuzu case at 135 mph... I ran an isuzu with a 282 whp 317 wtq SBC for a year and it didn't give up the ghost. Its OK for a cruiser and mashing the throttle in gear, but I wouldn't use it for the 1/4 mile or with sticky tires.
Reminds me... I had a customer pushing about 500 ftlbs out of a 3800SC through a 282 and taking it to track days. The 5th input gear is a heat-shrink press-fit on the input shaft. He was running high speed in 5th, unseated the press fit and then pushed 5th gear off its seat on the input shaft. I tore the transmission down and discovered this. I had the input shaft plated up and ground 0.0005 bigger stock, replaced the gear and reassembled. Haven't heard about any more problems with it...
Getrags push the intermediate shaft into the bellhousing in high torque applications. Destroys the tranny and the clutch.
Yes it all comes down to a transmissions design limits. Exceed those limits and eventually BOOM! It can be said that moderate use of a V8 /Getrag combo will hold up but then why do you need V8 horsepower and torque if that is your driving style?
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Yes it all comes down to a transmissions design limits. Exceed those limits and eventually BOOM! It can be said that moderate use of a V8 /Getrag combo will hold up but then why do you need V8 horsepower and torque if that is your driving style?
All the failures I've seen here on the forum have been from clutch drops, hard launches and generally being an idiot in first gear. Don't drop the clutch on 285's and it'll be fine...
Originally posted by Will: All the failures I've seen here on the forum have been from clutch drops, hard launches and generally being an idiot in first gear. Don't drop the clutch on 285's and it'll be fine...
Will said it all right there. However, not all of us who crave a bit more power than the rather anemic 2.8 feel it necessary to do burn outs until we destroy our trannies. fwiw: Helical gears produce a thrust factor which must be taken into account in the design of the a gear box. In most cases, the engineers include a safety factor of 1.5 or possibly as high as 2.0 in their calculations. This is to accommodate for discrepancies in materials & QC, not some idiot that stuffs a big engine in a Fiero & trashes the drive train by continuous abuse.
Will said it all right there. However, not all of us who crave a bit more power than the rather anemic 2.8 feel it necessary to do burn outs until we destroy our trannies. fwiw: Helical gears produce a thrust factor which must be taken into account in the design of the a gear box. In most cases, the engineers include a safety factor of 1.5 or possibly as high as 2.0 in their calculations. This is to accommodate for discrepancies in materials & QC, not some idiot that stuffs a big engine in a Fiero & trashes the drive train by continuous abuse.
Also, the analytical parameters--more than just safety factors--have gone up over time. Look at the bracing around the right diff bearing on the case of an F23 vs the case of a 282. The F23 case is obviously FAR stronger, even though the transmissions are designed for essentially the same range of engine power and vehicle weight. They even use the same (toothpick sized) FWD diff splines, so it's not like increased loading is the driving factor.
Please PM me with any offers.
