Yes, another 5 speed swap question (with a twist) - Transmission Forum

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Yes, another 5 speed swap question (with a twist)
Wednesday, June 12, 2013 5:02 PM
First off I would like to say that this site is an awesome resource. I am new here but I have been reading pretty heavily on here for the past few weeks. With that said, I have some questions about the automatic to five speed swap process in a 1996 Sunfire 2.2. I have read the other threads and have done some searching on here first, and didn't quite find all the info I need, so I figured I would start a thread and ask.

First off, let me explain my situation. I have converted a car that I drove on the street for 7 years, into a race car to run at a local asphalt circle track. The track is 3/8 of a mile, and moderately banked. The class I run in is a stock compact class, so the rules are very limited. I have raced the car a few times already and it's a consistent top 3 car as it is right now. I am considering several mods that will be within the rules, but the mod I am leaning most heavily toward is swapping in a 5 speed in place of the 4 speed automatic. I have access to every part needed for the swap for $150.

In reading, most of the info on the swap pertains to cars that people intend on driving on the street...so they have to worry about things like the console, getting around the dash, safety switches...etc. My car is completely gutted so I obviously don't have all of those concerns. My questions are...

1. Since this car is gutted and will never ever see a street again, can I just disregard hooking up the safety switch or will it disable the engine?
2. Is it absolutely necessary that I change out the ECM for one out of a manual car? I won't be shifting at all during races....these cars stay in 2nd gear once the green flag drops.
3. If I have to swap out ECM's, will that require a complete change of the wiring harness?
4. Will this swap help much in terms of freeing up a little horsepower through reduction of rotational weight and/or by gearing? Or am I wasting my time by freeing up 2 horsepower? lol
5. Am I going to hurt myself rather than help myself as far as gearing? I have 15" tires on the car currently.
6. Please let me know of anything I am not thinking to ask just yet....lol.

Basically I am looking for bare minimum procedure advice for a car that doesn't need all the bells and whistles to function properly on the street. I know it's a big job, but I'm willing to tackle it if the results are worth it. Any advice is greatly appreciated!

Thanks!

Re: Yes, another 5 speed swap question (with a twist)
Friday, June 14, 2013 7:39 AM
Let me go through your questions:

1. Since this car is gutted and will never ever see a street again, can I just disregard hooking up the safety switch or will it disable the engine?
There are a few threads saying what wires to hook up to disable the automatic transmissions neutral safety switch. Your car will lack a clutch safety switch if you don't add it in but the only detriment is starting it in gear with the clutch up... since it's a racecar I think you can disregard this as most racers go through a methodical checklist before the car is started.

2. Is it absolutely necessary that I change out the ECM for one out of a manual car? I won't be shifting at all during races....these cars stay in 2nd gear once the green flag drops.
No need to change it out, you will throw some auto transmission codes I think as sensors will be missing... again since it's a racecar you can simply disregard them

3. If I have to swap out ECM's, will that require a complete change of the wiring harness?
If you do find a donor ECM you can change the wiring harness under the hood pretty quickly but you can also just cut the auto stuff out of your current harness (leaving the neutral safety switch bypass hooked up) and plug it in.

4. Will this swap help much in terms of freeing up a little horsepower through reduction of rotational weight and/or by gearing? Or am I wasting my time by freeing up 2 horsepower? lol
This frees up a lot of mass - the transmission itself is heavier, has longer gears and on top of that carries a TON of fluid in it. Also, there are isuzu vehicles with transmissions with shorter gearing / FDR's that you may be able to play with to gain an advantage while staying within the rules.

5. Am I going to hurt myself rather than help myself as far as gearing? I have 15" tires on the car currently.
Absolutely not... the only thing that will be removed is consistency due to shifting but that's up to you and your skill to make up for!

6. Please let me know of anything I am not thinking to ask just yet....lol.
There will be some work involved to weld up the new transmission mounts and get everything in, you'll need the shift cables, shifter, etc from the donor, as well as pedals, clutch master cylinder and axles. You will want to swap out the rad, too. All in all I think it will be a worthwhile modification for you, even if it's just dropping weight and gaining a bit of gearing. I remember when stock Z24's were being dyno'd back in 2000 the 5spd 98's were putting down 126-128 whp consistently and the Autos were putting down 118-119 whp consistently. I realize you have an OHV 2.2 but hopefully that gives you an idea of what you stand to gain.


Let us know if you have any questions at all - heck some people might even have parts laying around that they'd sell you to make your life easier.

-Chris-


-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: Yes, another 5 speed swap question (with a twist)
Wednesday, June 26, 2013 10:36 PM
To trick the computer you need to cut the thick yellow and purple wires on the prndl switch. You'll just get 4 automatic codes but it will not affect the way it runs at all. You will also have to switch vss connectors unless your not worried about the speedometer. I just did a 5 speed swap a few weekends ago so if you have any questions feel free to pm me.
Re: Yes, another 5 speed swap question (with a twist)
Sunday, June 30, 2013 5:13 AM
FYI - automatic PCM will run 5 speed but they have torque management that retards the timing when it shifts so on a 5 speed it it think it needs to shift and retards the timing. This is for the 4 speed autos.
Re: Yes, another 5 speed swap question (with a twist)
Tuesday, August 13, 2013 12:07 PM
I know I'm a little late on the subject but I also do short track racing and I have a racing team. The teams most dominate car is a completely stock 96 5spd. I sold my 97/98 combo auto and hopped in a 5spd and there is a world or difference. It's just that much faster. I have seen autos come in first bit that was with a gutted tranny and stall converter. Pm me and we can talk some more.
Re: Yes, another 5 speed swap question (with a twist)
Monday, September 02, 2013 8:27 PM
I accidentally tried to use an Auto LD9 ECM on a 5 Speed LD9 (back before HPT, SC M45 install in a Pre2k, 99 ECM swap to delete EGR)...... With Check engine light, it also ran like crap. lol


SPD RCR Z - '02 Z24 420whp
SLO GOAT - '04 GTO 305whp
RACER X - '78 Opel Kadett W41 Swap

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