I have an 85 SE with the 2.5 and a 5 speed...Any idea what tranny it is or is there more than one 5 speed?Also,how does the 5 speed work with a 4.9 swap? Thanks,Paul
------------------ GOD,Family and Cars...And in that order...
There is a 99.99% probability that you have an Isuzu 5-speed. This is the only manual tranny offered on 4-cyl. Fieros. The only way you could have a Getrag 5-speed (which came on late '86-'88 V-6 Fieros) is if someone swapped them out, which is highly doubtful.
As far as how it'll do with a 4.9, I have no idea. Sorry!
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[This message has been edited by mrfiero (edited 04-27-2004).]
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01:29 AM
Songman Member
Posts: 12496 From: Nashville, TN Registered: Aug 2000
Mike knows this but, like I do so often was typing faster than he was thinking... The Isuzu is the only 5-speed that was offered on the 4-cylinders.... I was talking to Archie at the Knotts Berry Farm show this past weekend and he says he uses the Isuzu on all of his own cars that he V8s... That's gotta say something for them...
QUOTE]Originally posted by mrfiero: There is a 99.99% probability that you have an Isuzu 5-speed. This is the only manual tranny offered on 4-cyl. Fieros. The only way you could have a Getrag 5-speed (which came on late '86-'88 V-6 Fieros) is if someone swapped them out, which is highly doubtful. [/QUOTE]
Actually, it only a 99.93% probability that you have the Isuzu 5 speed. From what I have read, it is the preferred transmission by those using a manual trans with the 4.9. It offers different gear splits which many feel are better suited to the higher torque and relatively lower rpm limits of the 4.9.
------------------ FierOmar
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11:05 AM
longjonsilver Member
Posts: 1113 From: Lower Sackville, Nova Scotia Registered: Nov 2001
i chose the 4speed muncie economy transmission for my 4.9 swap. two reasons - it has the highest final drive ratio of all manual fiero transmissions - 3.30 as opposed to 3.6 or so for the getrag and isuzu5 speeds. some guys say that they could easily start out in 2nd gear with their5 speeds - so why have one? secondlyi have a 4 speed (4.10gear) in my 84 now and the transmission swap will be easy. i want high gearing to limit the wheel spin around town and keep the cops off my tail jon
------------------ I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!
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11:35 AM
FierOmar Member
Posts: 1649 From: Glendale, California, USA Registered: Dec 2001
Originally posted by longjonsilver: i chose the 4speed muncie economy transmission for my 4.9 swap. two reasons - it has the highest final drive ratio of all manual fiero transmissions - 3.30 as opposed to 3.6 or so for the getrag and isuzu5 speeds. some guys say that they could easily start out in 2nd gear with their5 speeds - so why have one? secondlyi have a 4 speed (4.10gear) in my 84 now and the transmission swap will be easy. i want high gearing to limit the wheel spin around town and keep the cops off my tail.
The MY8 trans with a 3.32 final drive is probably the second best choice (if not tied for first). The overall ratio of 4th gear is 2.42. By comparison, the overall ratio of 5th gear in the Isuzu trans (with 3.35 final drive) is is 2.48. Assuming that each were running at 2500 rpm in high gear on a stock Fiero rear tire (215-60-15), the 4 speed should be traveling 77 mph while the Isuzu will be traveling at 75 mph. In first gear at 5000 rpm the 4 speed would hit 32 mph while the Isuze would hit 30 mph. Thus, in my humble opinion, the difference between the low and high gears on these two trans is insignificant. However, for spirited driving, having the extra gear that the Isuzu has may offer some advantages. Nevertheless, for everyday cruising, your 4 speed should be fine.
------------------ FierOmar
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12:08 PM
KissMySSFiero Member
Posts: 5559 From: Tarpon Springs, FL USA Registered: Nov 2000
If you want to go for a ride, maybe I could get up that way or meet you half way in a few weeks. It is only a four speed. Let me know and may we can work something out.
------------------ Boys and Their Toys
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06:09 PM
windsweptfiero Member
Posts: 252 From: Scottville,Michigan,USA Registered: Jan 2004
If you want to go for a ride, maybe I could get up that way or meet you half way in a few weeks. It is only a four speed. Let me know and may we can work something out.
Lets do it!!!! I wish I had some Fiero buddys around here.I see that a lot of guys in the Florida area get together a lot.I work nights as a dispatcher so Im out in my shop everyday....
------------------ GOD,Family and Cars...And in that order...
Mike knows this but, like I do so often was typing faster than he was thinking... The Isuzu is the only 5-speed that was offered on the 4-cylinders.... I was talking to Archie at the Knotts Berry Farm show this past weekend and he says he uses the Isuzu on all of his own cars that he V8s... That's gotta say something for them...
D'oh! I originally typed in "only tranny offered...", but realized someone would say, "what about the auto?". I did type a bit too fast.....sorry. Anyway, like everyone else has stated, the Isuzu should be good enough behind a 4.9. Good luck on the swap!
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12:13 AM
windsweptfiero Member
Posts: 252 From: Scottville,Michigan,USA Registered: Jan 2004
D'oh! I originally typed in "only tranny offered...", but realized someone would say, "what about the auto?". I did type a bit too fast.....sorry. Anyway, like everyone else has stated, the Isuzu should be good enough behind a 4.9. Good luck on the swap!
I am surprised about that too but the people are following the manual point of this thread . btw the TH125 sucks behind the 4.9, don't do it!
***95 Camaro 3.4 swap, Ported and polished heads and intakes, CRX CAI, Custom Cam, AFP Regulator, steel vacuum lines, steel braided EGR tube, new Wire Harness, New Exhaust, No Cat, Flowmaster, polished poly dog bone. Isuzu 5 speed, Short through shifter ***Intrax 2" drop springs, Full Polly Suspension, Sencetrack Struts and Shocks, Grand AM brake upgrade, steel braided brake lines, 17" Gun Metal Wheels, Khumo Tires ***Racing Seats, SunPro tach w/ shift light, White face guages, carbon fiber Steering wheel, Carbon Fiber dash accents and custom sphere shift knob,
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02:57 PM
longjonsilver Member
Posts: 1113 From: Lower Sackville, Nova Scotia Registered: Nov 2001
The MY8 trans with a 3.32 final drive is probably the second best choice (if not tied for first). The overall ratio of 4th gear is 2.42. By comparison, the overall ratio of 5th gear in the Isuzu trans (with 3.35 final drive) is is 2.48. Assuming that each were running at 2500 rpm in high gear on a stock Fiero rear tire (215-60-15), the 4 speed should be traveling 77 mph while the Isuzu will be traveling at 75 mph. In first gear at 5000 rpm the 4 speed would hit 32 mph while the Isuze would hit 30 mph. Thus, in my humble opinion, the difference between the low and high gears on these two trans is insignificant. However, for spirited driving, having the extra gear that the Isuzu has may offer some advantages. Nevertheless, for everyday cruising, your 4 speed should be fine.
i dont plan to race, (well maybe a couple of friendly shootouts with the local vettes and stangs, just enough to show them who's boss around here) <ggg> i believe that rockcrawl won the 4.9 shootout at the drags in toronto(?) last year with a car having a 4 speed muncie- correct me if im wrong. anyway, the muncie economy tranny was priced right, low milage, and came complete with new seals, so i jumped on it. i didnt know that the isuzu was geared that high. i plan on continuing to use my 205 55R 16's so i will be 'geared' about the same. (although i might go to 215's in the rear. i hope to get some good highway mileage, and the PFI should help in that respect. jon
------------------ I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!
. btw the TH125 sucks behind the 4.9, don't do it!
