90/91 vs 92/93 Engine and Transmission Differences

ASSISTANCE Stock Engine-Bay Components
1

I have done a general search and have not found anything other than specs.

This is what I know so far:

90/91:
B18A1
Power: 90-91 Only: 132 bhp (98 kW) @ 6000 rpm & 121 ft·lbf (164 N·m) @ 5000 rpm
Transmission: 90-91: A1,S1, cable
OBD0

92/93:
B18A1
Power: 92-93 Only: 140 bhp (100 kW) @ 6300 rpm & 130 ft·lbf (180 N·m) @ 5000 rpm
Transmission: 92-93: YS1, cable
OBD1

My questions are:

  1. What gives the 92/93 more horsepower and more ft lb tourque? What are the engine internals/components that allow for for the increase? Is it possible to interchange the 92/93 engine internals/components on a 91 engine to gain the additional hp and torque?

  2. What are the differences in the transmissions? Can you bolt up a 92/93 ys1 transmission to an 91 engine without changing anything else?

I am familiar with the cosmetic differences for the most part. I am curious though, during my search I came across a thread about the cluster differences between 90/91 and 92/93. Are there any besides the obvious in the GS-R?

Any help is appreciated.

2

The '92-93 has different camshafts and a different intake manifold, thus slightly more power.

If you wanted to use a '92-93 transmission you’d need to use the '92-93 clutch disc, as the splines are different. Everything else would bolt up.

3

So I could take the camshafts from a 92/93 and intake manifold and install it on my 91 without any problems?

4

If you really wanted to, yes.

5

This has been covered a bizzillion times.

6

Searching is overrated Colin… you should know this by now!

7

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