His car should have a broader torque curve, but as I see it the brakes are the big difference.

928 weights in NASA Supercup and PCA SP3
3100 - 4.5L "928"
3200 - 4.7L "928S"
+100lbs for Euro if the engine/tranny/brakes are different than US.
+100lbs for brake upgrades, wider wheels (and anything else considered 'prepared')

 

That is interesting. I spoke with Vito and he has the car down to about 3100lbs. 400lbs is a lot of weight to have to put back on to race it. In fact, he has more weight that can come off. I'll probably take a look later this week/weekend.

Anyone hear of any others for sale?

Dennis, any regrets on the S4 conversion?

 

I still think the best combo would be to get an 86.5, so you get the brakes as well, and have the hotter cam (same as GT). but, you need to get the heads from an S4 and put them on the 85.6. this would give the larger valves and raise the compression by a point or two. I wonder when someone is going to do this??

the chassis are all the same , as actually, the holbert car is an '86 automatic that was converted to an s4 stick!

mk

 

Actually, there are several changes throughout the years. Later weight more, but get better suspension mounts.

 

And that was when the Titanium engine was installed.

 

I would presume you would need to go with the S4 intake as well. Unless I am wrong they bolt on slightly differently. Of course if you changed the intake, then you are probably going with the S4 fuel and air setup, so you might need to address that in the 86 chassis as well. So it might be a non-trivial process.

 

Hmmm. Regrets? I'd have to say no regrets about using a 928S4. Even though I've had issues, I've had a lot of fun too. I've seen plenty of friends blow up stuff no matter what make/model. I do question myself - though it's more along the lines of "why do I have to like racing vs. a cheaper hobby like golf or knitting?" But I've never had a conversation at lunch at a track/race day where somebody doesn't mention that.

 

Good points, Stan. Maybe a really good top end rebuild and valve job on the 86.5 head would be a better option. Are the 86.5 cams really that much hotter than the S4's? Where exactly did the 30 extra horses come from between the 86.5 to the 87? Bigger valves? Intake manifold and better computer control of combustion?

 

more aggressive spark and fuelling imo.

 

I'll have my black 87 5-spd for sale soon....will be a great track car candidate.

Rich

 

Rich

Not if I buy it 1st!!!!!!!!!!!!!!!!!!!

 

Yes, the 85/86 cams are a more aggressive grind then the S4 cams, as MK said they are close to the GT cam grind.

I don't know exactly, but there are many differences, including the heads, cams & intake.

 

Ive heard that the 85 intake could flow better than the S4 intake if you dont mind not having the flappy effect. (ive pinned mine open for racing)

the valves are bigger with the S4 heads, but arent they the same castings so the 85 intakes can be installed on them?

However, by putting S4 heads on an 85 block, the compression would be increased and that could be a good adder

my only concern is where the 25hp came from with the 86 to the 87S4.
could it just be the valve size? if not, then we are talking the computer differences. However, dont the 86s get a good boost when the chips are used?

mk

 

'Cause you're sooo not a knitting kind of guy!

<picturing Dennis sitting in a chair knitting...>

 

No doubt, JL's 2:32.00 (..recorded with a HotLap) at RA in his stock-block, 275 rwhp NA 4.7 Euro is the time to shoot for; I've got 3+ seconds to go before matching that!

For some reason, golf does not have the same excitement factor as coming into a hard, downhill left-hander at 140+ mph needing to slow down to 55ish prior to navigating it. IMO, the best, most exciting job in the whole wide world has to be a fighter pilot, and the closest I'll ever come to being one is driving on the track, as I did not have the perfect non-corrected eyesight required by the Air Force.