angrysmileyface

I am looking at getting a spare auto trans for my 94 wagon and have located a fairly low mileage unit for a decent price. While I know the f22b1 engines are slightly different, is there any real difference between the transmission and thier electrical and physical needs? Parts sites say the outer case is the same.for all 4 years so I'm not worried about physical mounting.

angrysmileyface

Any thoughts?

MAD_MIKE

90-97 H4As are all the same physically and electrically. Spiritually they are different.

94-97 Accords have the most conservative gearing.
F22B1/B2 195/60R15(24.2" tall tire)
2.736 1
1.483 2
1.026 3
0.674 4
4.133
94-97 Accord Wagons have the same 1-4 gears but a slightly lower FD of 4.285.

92-96 Prelude S(F22A1) models have the 90-93 Accord gearset 185/70R14 (24.3" tall tire)
2.705 1
1.464 2
1.028 3
0.707 4
4.285

92-96 Prelude Si(H23A1) models *non-VTEC* 205/55R15 (23.9" tall tire)
2.705 1
1.535 2
1.057 3
0.750 4
4.428

95-97 Odyssey(F22B6) models(MPJA) 205/65R15(25.5" tall tire)
I'm not sure of the gear ratios, they are lower than others, been meaning to look up an Ody FSM and check the gear ratios. As well as verify the above gear sets.

In my '95 Coupe the MPJA FD has the engine ~3Krpm @70MPH and ~4Krpm @80MPH.(factory Accord tach with 195/60R15) This easily can get the accord up to triple digits at the cost of engine revs, fun trans, but if you plan on doing lots of 70+MPH cruising a different trans should probably be considered for better economy. If you plan on hauling lots of gear or are going to be in hilly areas the 4th gear is great for getting up to a higher gear at lower speeds. With a full car and junk in the trunk the Coupe has no problems keeping up with traffic.

If one were to keep the original smaller diameter TC from the B1 paired to this trans it would make the car a bit quicker off the line. As it is the car is quick enough, leaning on the throttle slightly the car gets through an intersection fairly quick. I've unknowingly aggravated people in the other lane as I simply accelerate away with little fuss yet pull away. Pony car crowd gets a bit touchy when a 20yo Accord gently walks them through an intersection. V6 Ponycars are really pissy folk.

If I were to do it again, I would probably opt for the MP1A-#######, or the MP1A-*1*######(LSD) units from the Preludes. Still have good gear sets but not at the cost of highway revving. Traffic around here is getting nuts, 80MPH just to stay with in the slow lane while twisting 4Krpm is not my idea of fun for the B1. Fuel cutoff cuts in around 120MPH, which considering the age of the car as is, is fine by me. Anything above that really requires more tire/brakes to be safe. Something I'm not really up to change just yet on the occasional WOT onramp blast.

One other note, I haven't properly verified this, from a dead stop WOT up to 80MPH the car pulls no problem, but noses over unless I back off or let it into 4th. If I hold the car will definitely begin to slow down. I'm leaning on the side that the original fuel pump*cough*330Kmiles*cough* may just not be up to par anymore.

Fitz Williams

iTrader: (1)

I am considering putting a Prelude trans in my 94 Accord. So I will need to change the TCU. I see the the 92-93 uses a different part number from the 94-95. Do you know if there is any difference? And, of course, the S is different from the SI. I assume this is because of the difference in gearing between the two.

MAD_MIKE

Why change the TCU? H4A is the same electrically between 90-97.
ECU/TCU do not care about gear ratios, gear changes are changed due to speed, throttle input(TPS/TV cable) and load conditions.
TCU and ECUs are designed for the car and engine they are in, changing this out may have the car automatically shift into a gear at an undesired rpm or rpm range.
94-97s did not have the S button so if you install a TCU without the S button it is kind of pointless.

Fitz Williams

iTrader: (1)

My thinking was that the TCU should be the one Honda used for the transmission installed in the car. Else why would the Prelude S and the Prelude SI have different numbers. I had planned to try some different ones and see what the results were.

MAD_MIKE

What's the biggest drivetrain/powertrain difference in these cars?
SI H23 160HP torque machine is going to have much different torque/power curves from an S F22A1 135HP nugget.

Shift points, especially WOT ones, are going to be very different between the two engines. Shifts will be to keep the engine in the meat of its power range.
If the engine is still within a few HP of peak, 500rpm after it is best to delay the shift engine is still producing good, usable power.
If the engine loses power after peak and drops 10HP or more then the engine is nosing over. Don't be fooled by 'redlining' an engine, that is just the physical(not power) limitations of the engine. Generally shift points are going to be from peak HP rpm back down into the peak torque, that is the power band of the engine.
There may be some tweaking in the shift points due to other reasons(emissions/mileage/warranty+durability) but generally the shift points are to match engines usable power.

Fitz Williams

iTrader: (1)

One of my main reasons for going Prelude SI with the trans was the lower spaced second gear ratio. With the Accord ratios, the gap between first and second is just too big. Second needs to be lower. So that when the shift to second happens the RPM's won't drop to nothing. I am not really interested in peak RPM's because an auto is just not suited to that kind of driving anyway. I guess the TCU will not matter much for that, so the original should be OK.