Engine differences - 88 924s vs 84 944

[Reason]

I don't want to turn this into a 944 vs 924S thread, but I am considering getting into an early year 944 (currently have an 88 924S) and I didn't realize until just now that they were significantly down on power (143 vs 160). What contributed to these power differences?

[v2rocket_aka944]

84 has a milder camshaft and lower compression. also a different DME tune, the 88 runs on premium gas, the 84 on regular pump.

early US 944 is rated 143hp, 88 should be ~152-155.

[jcommin]

Originally Posted by v2rocket_aka944

84 has a milder camshaft and lower compression. also a different DME tune, the 88 runs on premium gas, the 84 on regular pump.

early US 944 is rated 143hp, 88 should be ~152-155.

I have an 83 and it runs on premium.

[v2rocket_aka944]

Unless you have Euro 83-87 or US 88 pistons in there, it only needs 87 octane...assuming you have the stock DME/tune.

On my gas filler the sticker says (RON+MON)/2 = 86...as in, 86 "octane" on the AKI index which is what the US uses.

There is no functional difference between your 1983 and my 1985 engines, if both are US spec.

[Reason]

Originally Posted by v2rocket_aka944

84 has a milder camshaft and lower compression. also a different DME tune, the 88 runs on premium gas, the 84 on regular pump.

early US 944 is rated 143hp, 88 should be ~152-155.

Thanks

Sounds like it's likely not worth chasing the later engine's output then. Money better spent elsewhere (until a rebuild is needed, then different story...) I was hoping it was all electronics, given that Europe got the full strength 2.5 early on.

[v2rocket_aka944]

US vs Euro 83-87 power difference was all due to emissions...

US car needed:
- lower compression (9.5 vs 10.6, for NOx reduction)
- catalytic converter (for NOx reduction and CO/HC breakdown)
- milder tune (to lower emissions, and to run on "regular gas" which US buyers loved)

the late car will feel snappier off the line and faster everywhere...but once you drive the early car for a while, you won't notice...

[Reason]

Issue is that I'd be giving up my 88 924S for the 84 944. Given the lighter weight of of the 924S, and the last year receiving the full 160hp, it makes me wonder if I am going to miss those 17 ponies. In reality it will likely come more down to gearing and general health of the car.

[v2rocket_aka944]

if you get out of the 924S and get into the 84 within a few days you will notice.
but it will fade soon enough.

if a few weeks pass you won't know the difference.
i had my 944 tuned up to 160hp for a while and then put it back to stock 143hp for smog...felt slow at first but still fun. after a few weeks, didnt care.

[Swennydawg]

The '88 924S is the preferred Porsche for most 924 guys.

[sausagehacker]

Even a half decent tune will make more of a difference than the pistons will. I'm probably up 10-15hp just from that, tuned for 93 or E85 depending on what I'm running that week.

[Fast Freddy 944]

I have the 951, and its good for 225, I have a few minor tweeks boosting it to 250 bhp, now if I just find some cv joints that wont fall apart out of the box. lol