Engine Mod advise / views welcomed

[Diver944]

It's nice to keep a Porsche engine in a Porsche car but personally I would love to see some LS1's in UK cars [8D] They sounds so gorgeous in the US videos that I have seen and it finally addresses the major weakness in the 944 line, the engine note

I'll leave it to someone else though [] preferably with their own oil well []

 

[Diver944]

Oooh I forgot to mention that during one of the visits to LIL when her engine was in pieces in SimonP's workshop he showed me a variable vane turbine that he already had [8D]

 

[George Elliott]

Interesting comments so far, thanks everybody.

I am a purist, Porsche engines come from Germany, and should be strong, light and compact, (IMO the 928 should have a 4 cyl turbo, or twin turbo - a small one & a big one a la 959). Nothing against the LS1, it seems to be highly regarded by many of you, so it must be good in its place.

The theme seems to be Airflow thru the Motor, increase swept volume, keep the revs moderate, boost moderate, derestrict the IC, eliminate back pressure on the hot impeller-bigger downpipe & exhaust, then ensure fuel supply - bigger injectors and higher FPReg, DPW to avoid losses,
Mass flow remains a grey area for me but I have a sci-vision & I like it, I want to keep the standard motronic, would the sci-vis work on a 2.8, or is the Vitesse a better bet?? I prefer a stealth appearance, and I dont want to mess with it when its set.
What Turbo to feed a 2.8? K27/8 off a 911 3.3 - will it fit? I like the water cooled KKK as its robust. The fancy V.Vane Garretts look good - but they address a problem I dont have a problem with, Lag - we know its there so open the taps accordingly.
Spark strength needs an upgrade,among the things I have discussed with Andrew. Not yet sure how though.
Hydraulic lifters,Crank Rods Pistons. Bore refresh to 100.5mm I guess.
AFR & Boost guages are a must for me.
I am uncertain of the std inlet manifold.
I am happy with std 250turbo brakes & clutch (i have never worn one out in 25 yrs - 5yrs in 44t's), & LSD for road use.
Finally, how can I get progressive torque, ie boost "rising rate" control, - currently my 18psi 2.5 can get a bit wriggly overtaking in the wet with new conti sport contacts, and a careful right foot. As for Slip roads....3rd gear.......do they put diesel on them??[>:]

Again, thanks for all your experience, & comments, I am nearer to the spec for this engine and look forward to your steer on my summary.

George

dme relay,belts,tensioners,plug leads,water pump,fuel lines,disc's/pads,wheel bearings,window motors, horns,sills - been there........

 

[sawood12]

I think the only way to get all the characteristics you need is to go down either the piggy back or stand alone route for your EMS. These systems can control so many parameters to such a high resolution you can really tweak the engine to its limits. Beyond that you are into making hardware changes to get further improvements. Unfortunately a flat torque curve is difficult to achieve with an 4cyl in-line engine as you have a full 180 degrees of crank rotation before the next power stroke comes in. To flatten that torque curve you need more cylinders because ultimately torque is a characteristic of the physical mechanics of the engine. You can get the best out of what you've got with EMS, and all the other bells and whistles you can bolt onto the engine, but ultimately it boils down to bore, stroke, number of cylinders and capacity. Just where those limits are on a 951 engine has yet to be established.

When it comes to traction as I said before you are going to struggle when you get upto and over 350bhp. The relatively unsophisticated rear suspension and 50/50 weight distribution are not good for traction. Again with a stand alone EMS it is possible to get traction control, but wheres the fun in developing your engine to produce 350bhp for it only to be limited by the TCS. Although on track with a set of slicks it would be awsome.

My personal aim is to get a modest level of BHP and torque and concentrate on the delivery of that performance.

 

[George Elliott]

Oooh I forgot to mention that during one of the visits to LIL when her engine was in pieces in SimonP's workshop he showed me a variable vane turbine that he already had [8D]

Paul, A weapon of mass dest......forgot to mention....[8|]
John McEnroe would say "you can not be....[]
Interesting how turbo technology is moving on...
George