Best Chip for 944 S?

[Gatornapper]

Who has the best chip for the 944 S?

What other simple HP upgrades are there other than CAT delete? O2 sensor?

TIA!

GN

[walfreyydo]

Biggest gains will be seen by removing the AFM for a MAF or MAP system via going standalone. On S2's I have heard claims of ~20hp gains. This is because the AFM is very restrictive and newer systems (MAP and MAF) are available to retrofit onto these older cars. The added benefit is no longer having to rely on potentially problematic and old DME

Will require fitting a map or maf sensor, running a 951 tps, wideband o2, intake air temp sensor and the actual standalone ecu.

All of this can be done with the Megasquirt PNP system (requires very little rewiring but does require some tuning, which will essentially allow you to create your own custom "chip"): https://www.diyautotune.com/product/megasquirtpnp-gen2-p8791-for-87-91-porsche-944-s-s2/

Theres also Vitesse and others.

A chip isnt worth the dollar to hp ratio compared to the above and I am not sure if they are even available. Cams are another option but more expensive than converting to MAF/MAP.

Cat delete you will see minimal gains. The 16v exhaust manifolds being tubular, are already pretty efficient so not much to gain there.

Im sure others will chime in.

[Gatornapper]

Tyler -

Wow. A book worth of info here.

Pretty much came to same conclusion on chip.

Big surprise is your statement on the CAT delete not doing much. That's a big surprise. Think my Cat is original with 150k miles on it. Seems in spite of great tubular exhaust manifold that it would be a point of restriction in flow. ????

Think the Megasquirt option is a bit more than I want to tackle.

Not interested in cams. What about Woodruff key that advances cam?

GN

Originally Posted by walfreyydo

Biggest gains will be seen by removing the AFM for a MAF or MAP system via going standalone. On S2's I have heard claims of ~20hp gains. This is because the AFM is very restrictive and newer systems (MAP and MAF) are available to retrofit onto these older cars. The added benefit is no longer having to rely on potentially problematic and old DME

Will require fitting a map or maf sensor, running a 951 tps, wideband o2, intake air temp sensor and the actual standalone ecu.

All of this can be done with the Megasquirt PNP system (requires very little rewiring but does require some tuning, which will essentially allow you to create your own custom "chip"): https://www.diyautotune.com/product/megasquirtpnp-gen2-p8791-for-87-91-porsche-944-s-s2/

Theres also Vitesse and others.

A chip isnt worth the dollar to hp ratio compared to the above and I am not sure if they are even available. Cams are another option but more expensive than converting to MAF/MAP.

Cat delete you will see minimal gains. The 16v exhaust manifolds being tubular, are already pretty efficient so not much to gain there.

Im sure others will chime in.

[Jfrahm]

The S has an adjustable cam sprocket so you can play around with cam timing if you want.

[djnolan]

The 16 valve engines have a very refined system even if it still uses an AFM. I think there is more to be gained on emissions than power for any 16V MAF conversion. There was a long thread on S2 MAF conversions several years ago that discussed this.

[kdjones2000]

AFAIK there are zero chip options available for the 944S.

Enjoy it for what it is...

[J1NX3D]

F9T is developing a MAF conversion for the 944S and 944S2- i.e. the 16v cars. It's still probably a wee way off but they say it's coming. If you're looking for an off the shelf solution better than a chip but short of a standalone I would wait for this and spend time and energy on more traditional things like maintenance, suspension and tyres/wheels.

[Gatornapper]

Many thanks to all. Car is almost all new parts in critical areas like suspension, tires, racing clutch, exhaust, etc. Very happy with all that. Really pleased with engine, I just like tweaking things to the max in little and simple ways. I can certainly live with it the way it is. I love driving this car more every day - in some ways more than my Cayman S....and the 5-speed keeps me in that wonderful world of always seeking that ever elusive perfect shift.....

Otherwise like keeping original.

Had no idea the S had an adjustable cam sprocket......for each cam? Where might I find some guidance on tweaking there?

TIA,

GN

[Gatornapper]

KD -

Cruise Control is intermittent in availability. Likely cause? Like it on trips, but don't have to have it.....

GN

Originally Posted by kdjones2000

AFAIK there are zero chip options available for the 944S.

Enjoy it for what it is...

[J1NX3D]

The 944S2 intake assembly on a 944S is supposed to be an in improvement but empirical evidence of any gains is patchy but some who have done it have measured an improvement on their butt dyno.

https://rennlist.com/forums/924-931-944-951-968-forum/981532-944-s2-intake-manifold-on-944s.html

[kdjones2000]

Originally Posted by Gatornapper

KD -

Cruise Control is intermittent in availability. Likely cause? Like it on trips, but don't have to have it.....

GN

Should be fixable... Send me a PM for details

[djnolan]

If you are thinking about the S2 to S intake swap this dissuaded me:

S and S2 port matching

[J1NX3D]

I had read that before too. The guys that have done the mod need to do some proper testing to verify the claims. I do know of a Porsche tech here in NZ who did it to his 944S and was very happy with the results.

[Jfrahm]

The S and S2 cams are chained together and adjusted together. Instructions for setting/adjusting the cam timing are part of the 16v cambelt procedure in the FSM.

You can look at how this 928 product is used to fine tune cam adjustments:
https://928motorsports.com/wp-content/uploads/2021/11/32VCamTimingManual.pdf

In your case I would suggest just marking where you are at now (very carefully) and testing, then testing the extremes of adjustment. In my experience the butt-dyno will tell you nothing for this sort of thing.

I spent quite a while dialing in the cam adjustments on a 40v Audi V8 and got no perceptible performance improvement or better MPG or anything.

Actually also some muppet the PO'd had work on one of my 928S4s had one bank so far out of whack they'd cut one of the bolts off the ignition rotor. One of the oval sprocket holes was no longer aligned with the cam drive tripod-thing behind it. Car ran fine. Ran the same with this issue corrected, as far as I could tell just driving it.

IMO it's more realistic to move to a 3.0, you could spend a ton modding an S and still get walked by a stock S2. If you do try modding, the placebo effect is HUGE when modding cars so you will need a good way to measure improvements taking into account the temperature, humidity, etc.

[Gatornapper]

Tyler -

I REALLY like the idea of converting to MAP or MAF. The AFM does look very restrictive.

Too many other $$ projects going on with my '76 914 right now so may be a while before I have the free $$$ for a conversion - but I do want to do it.

QUESTION on CAT delete. As CAT is way past the tubular exhaust manifolds, and they are inherently restrictive themselves, I cannot see how removing the 35 year old CAT cannot help a lot.

Can you help me understand that?

GN

Originally Posted by walfreyydo

Biggest gains will be seen by removing the AFM for a MAF or MAP system via going standalone. On S2's I have heard claims of ~20hp gains. This is because the AFM is very restrictive and newer systems (MAP and MAF) are available to retrofit onto these older cars. The added benefit is no longer having to rely on potentially problematic and old DME

Will require fitting a map or maf sensor, running a 951 tps, wideband o2, intake air temp sensor and the actual standalone ecu.

All of this can be done with the Megasquirt PNP system (requires very little rewiring but does require some tuning, which will essentially allow you to create your own custom "chip"): https://www.diyautotune.com/product/megasquirtpnp-gen2-p8791-for-87-91-porsche-944-s-s2/

Theres also Vitesse and others.

A chip isnt worth the dollar to hp ratio compared to the above and I am not sure if they are even available. Cams are another option but more expensive than converting to MAF/MAP.

Cat delete you will see minimal gains. The 16v exhaust manifolds being tubular, are already pretty efficient so not much to gain there.

Im sure others will chime in.

[Gatornapper]

Thanks! I watched a German video with English subtitles on this and it is something I definitely want to do.

But I don't have all the dial gauges and even if I did think this is above my pay grade. Trouble is top local shops that can do it will charge three inheritances and take 4 years.

If there were a video of a more simple way to do it, I'd be in.

GN

Originally Posted by Jfrahm

The S has an adjustable cam sprocket so you can play around with cam timing if you want.

[Jfrahm]

IMO skip the dial gauges, just mark where you are now on the cam sprocket (after testing) and play around with it.

Or, skip that and look ahead to a car with more motor fitted from the factory as honestly there's not going to be much to be found. Whatever you do, be able to return to stock as stock is worth a lot more when selling.

[walfreyydo]

Originally Posted by Gatornapper

Tyler -

I REALLY like the idea of converting to MAP or MAF. The AFM does look very restrictive.

Too many other $$ projects going on with my '76 914 right now so may be a while before I have the free $$$ for a conversion - but I do want to do it.

QUESTION on CAT delete. As CAT is way past the tubular exhaust manifolds, and they are inherently restrictive themselves, I cannot see how removing the 35 year old CAT cannot help a lot.

Can you help me understand that?

GN

You will feel additional hp with a removed cat but it will be minimal - likely no more than 5 hp I would guess.

Secondly, removing the cat without putting a resonator in its place will make the exhaust sound very raspy. So if you do go this route, consider some sort of resonator to preserve a nice sound.

I went with a 200 cell high flow universal cat from flowmaster and put an additional small 12-14" (or so) resonator behind it - Im not sure the cat actually does anything since the exhaust smells like raw fumes. In hindsight I would have just gone no cat. The old original OEM cat that was on my car was basically completely destroyed and non functioning anyways. When I removed it, large chunks of cat material would freely fall out. I am running a modified stock S2 exhaust, which for the most part was in good shape when I bought the car besides the cat.

[J1NX3D]

My '86 had a factory resonator/primary muffler instead of a cat. I think removing the cat will be a negligible improvement unless it was already stuffed, but would help with overall performance with other mods.

[Gatornapper]

Thanks to all for all the good advice.

On S2 intake: no thank you, more than I want to get into.

On Cat delete: as my cat is original w/over 150k miles on it, it almost has to be restricting the flow. I'll put in a straight pipe after removing it. If I don't like sound, I'll put in a free-flow cat instead of resonator. Muffler is a new Flowmaster for the car and sounds nice.

Convert to MAP or MAF - someday w/new ECU. .... someday.......

Many thanks to the brain-trust for saving me from wrong moves on this sweet car that I want to keep as original as possible.

GN