bad_monkey

Confirmed, 2.7 exhaust is a similar cast 2-piece, no notable changes... A stahl type straight tube header has always been noted as one NA performance improvement, so I hope that your methods find some gains there.

Very interesting that you didn't find more power higher up the power curve. I completed the gerotor designs to (hopefully) reduce oil pump over-driving and cavitation. From these experiments, however, the 8v seems to have more to give in low-end and part-throttle grunt.

Did you change the tune when you made the mods? Or just look to see if there was a change in hp/tq.

Are you thinking about a cam with more of everything - lift, duration, overlap? I reckon there's a few percent to be gained there while retaining stock components.

I'm busily auctioning off stuff for funds for an NA Tune and cam key...

Rogue_Ant

Charlie, thanks for confirming that the headers are the same.
Interesting about the header... Is there any before / after dynos of just the header? I can have FRF make me a long-tube 4-1 header, but I don't want to invest a lot of money for something that doesn't have any real gains.

Yes, most of the power increase was <6000rpm, but this is where the car exists anyway. I bet that the majority of the reason it was reluctant to gain much on the top-end is due to the camshaft. The cam refrains I will try does increase everything: lift, duration, & overlap.

The NA-Tne has 3-dimensional timing tables that uses load. So any physical engine changes I did, the Tune automatically adjust for them. I did try to do some tweaking of the timing & AFR after the engine changes, but there wasn't any extra power to be found. I think that this speaks well to the adaptability of the NA-Tune.

I will send you a PM regarding the oil-pump gear.

MAGK944

Just measured and tb's are the same, 55mm na and 951. The S2 or 951S might be bigger.

Top 951, bottom 2.5na both throttle plates have a "4" stamped in them.

Rogue_Ant

The 951S is the same - I'm pretty sure.
So, now the question is what about the S/S2/968 throttlebodies, or another one that is easier to get?

catamax944

I think the '86 928 throttlebody could be the best option
http://www.ebay.co.uk/itm/PORSCHE-92...item5aea1c75df

F40LM

Hey Josh,

Dropped my DME in the mail for 28 pin conversion. Check your email when you get a chance.

Michael

Chunkerz

Is the 928 throttle body just plug and play, or will some fabrication be required?

blown 944

wow interesting. I must have been measuring an early one or something?? I dileberately measured them back when I was doing the SC car. Again..Interesting and I stand corrected.

Rogue_Ant

Some fabrication required...

MAGK944

iirc the 928 tb's are in the 65-70mm range, would think they would be too large. Anyone have an 3.0 S2 to measure? Surley it must be bigger than the 2.5's.

Btw, just tried the na TPS on the 951 spindle and it fits perfectly, so it should fit the S2 also. Therefore there shouldn't be any issues with mounting the 2.5na (single-stage) TPS to a later tb.

Dimi 944

I can measure the 3.0L TB and post it tomorrow.

Rogue_Ant

What about something like this one:

http://www.ebay.com/itm/BMW-E23-735i...adfd41&vxp=mtr

62-63mm I think...

J1NX3D

if i get a chance i'll measure my 968's tb this afternoon after work.

Rogue_Ant

Cool, let us know!

J1NX3D

someone might want to double check theirs, mines still fitted and measuring was difficult but I think it's 55mm also.