The Fixer

2720 lbs. with an 1/8 tank. but who's counting lol,

If you do come to PA doc, please pm me in advance and let me know

where you'll be. You may be close to Philadelphia.

I'd like to see the plane and ask you to drive the RS.

Take care,

Matt

Ketchmi

docmirror, you are joking about the supercharger gains aren't you? If you are ever in the SLC area I would be glad to take you for a ride in a toy or two. I have an 89' auto running 630rwhp using a Vortech V7Ysi and the only engine mods done are a set of cometic head gaskets that drop the static compression ratio 1/2 point. Oh yeah, this car is daily driven and had had this configuration at 15.5psi running for several years now with only one belt change. It did destroy a transmission and several sets of rear tires though...

As far as parasitic loss due to the belt drive, comparing my configuration to Mr. Kuhn's twin turbo setup he achieved 550rwhp at 12.5psi and I achieved 545rwhp at the same pressure. Where exactly is this massive parasitic loss due to driving the supercharger?

I would consider these significant gains...my latest 88' did 526rwhp on 8.5psi with a set of Elgin grind cams and one of my full exhausts. No other mods to the engine at all, just tuned properly. Oh yeah, at this altitude (4500' above sea level) I haven't pulled any timing from either configuration either.

Even with a nice intercooler I'd be willing to bet that the total weight increase is less than 100#. More than offset by the extreme giggle factor when the boost comes on.

People on this board listen to you, you have/share a lot of knowledge and help tons of people but in this subject you are simply mistaken. Tim's kits are pretty prevalent and if you ask any one of his customers you will find that they don't consider their performance gains "modest". A properly setup 32v supercharged car will run with some of the best supercars out today. The 88' i mentioned outran a new Shelby 662hp mustang on the highway and exceeded 200mph in the process. It actually suprised the owners of both cars.

docmirror

I've got no dog in the supercharger hunt. I'm not going to debate what one considers as modest gains, or exceptional gains. Some SC cars see a good boost because they start out with modest HP already, and anything is an improvement.

My point, and it's still valid is gaining HP just by strapping on a blower BY ITSELF, isn't a good plan for either high gains, or reliable engine operation. Most SC installs that are successful have boost controllers, knock detection with ignition control, some have water injection, piston changes, C/R changes, cam timing changes, overlap, dual spark, shower of spark, large radius crank rod journals, and I could go on and on.

I'm a fan of more HP, and if it were that easy as just strapping on a blower and mash the go pedal, I'd love to have one. Just today I was at Seans house and we were talking about his current task to install a blower on one of the Strosek wide body cars. I looked at the bits, and it's not too complicated, but it's no simple task either or the OP might be doing it. As for the weight, in this case, 100Lbs is significant where the car weighs less than 2800. Although for 100Lbs, a gain of 200HP would be pretty sweet.

If I get back to UT area, I'll come visit and have a ride.

Ketchmi

I'll be glad to give you a ride and the 88' I mentioned is back for some "upgrades". Just minor stuff like being turned into a 6.0L and going from a 1000cfm supercharger to a 1400cfm supercharger, that should take it near the top of the pecking order of all supercars. We are already allowing for the 6 speed upgrade as we know that the factory trans will cry uncle soon. The GTS clutch in it before was at the ragged edge at 526rwhp in fact I was pretty impressed that it held at all.

All of my builds/installs have been successful (so far) with minimal problems or additional maintenance required. I am toying with designing a different supercharger setup but it may be for a limited crowd at best as I don't really want to put it into production, just see how good I can make it. The goals are quiet, hidden and 500+ reliable rwhp. Most people would never know it was there until I put it to use.

If you do make it up here I will even supply your beverage of choice for afterwards.

MjRocket

Now that's one hell of a deal...Gitty up!

Imo000

Build a non intercooled low boost SC setup, like mine, and you'll be laughing all the way to tge bank. You could pull it off for around $1K, get around 6psi and around 100hp. You are more than capable to build it. Put it where the AC compressor used to be and the added weight will be low to the ground.

The Fixer

You did a nice job with yours.

I was just commenting on the theory that doubling the air into the cylinder would theoretically double the HP but if not for the power required to run the supercharger itself.

Bill Miller Engineering's 14-71 superchargers making 60 psi boost while 50% over driven require between 900 and 1000 hp just to run the blower.
(This information is from Bill Miller himself)

The engines using his blowers make around 8000 hp.

Re '86 exhaust manifold install:

My exhaust now weighs 32 lbs total, 1 pound less than the rear muffler alone. '85-'86 manifolds to Y to straight 2.5" pipe with one 80 degree bend.
Noticed a difference in the way it revs when not under load, which felt better.
I think if i can get the back pressure just right it will run like a champ.
It runs very well at high rpm only, but is CRAZY loud. Low end is meh, needs back pressure i think.

A $3 exhaust adapter (label in pic) purchased at Autozone and a little heat and the Y fits better than it ever did.

Any advice to make it sound great while adding some needed back pressure is appreciated, experimenting with exhaust configurations can get expensive.

Jadz928

Try dynamax bullet right behind the 'Y'.

Lookin' real good, Matthew! Most enjoyable thread on RL.

AirtekHVAC

Hey! Screw you!

Just kidding....lol.....I guess it's a "good thread".....

Great work Matt!

The Fixer

[QUOTE=Jadz928;11455890]Try dynamax bullet right behind the 'Y'.


You think that will do it? I was looking at them. Will try. Thanks Jim!

I will rid the exhaust of the useless (no longer flex) union in the middle,
no need for it anyway. unneeded 1/2 pound probably.


Ron, you can have me old cast manifolds, it will only be $200 to ship them!



I have something on my mind.

I was talking with the other Porsche magazine editor by email recently.
They seemed to be really interested in the RS. Very interested.

Couldn't believe how lite etc., etc., asked me: How did you get it so lite?
I responded in detail (never get that 20 minutes back)
Sent them lots of pics from get go.

Seemed they were going to do good on their promise to be more inclusive.

3 emails in a row, (more pics, more interest)

Then i mentioned again: i thought it made a better track toy than the 964 911 RSA and would outperform the lite 3.2 Carrera (2550 lbs) i drove for 13 years as it was a better handling car and had more go.

Now nothing, crickets. I'm not sure they are no longer interested but the convo all stopped after my findings re 911 vs lite 928

i will not make any attempt at finding out if they still are interested as before. I don't care all that much, and i'm too busy anyway right now

with work to have something else to deal with.

But I am convinced these guys are 911 lovers and anything else (road cars from '80s) doesn't do it for them.

Don't ever disparage the 911 lest you be shunned by the Porsche cognoscenti. (insert my laughter here)

Conclusion:

We are all we have to share in the enjoyment these wonderfully made and beautiful Porsches bring to us.

And you all are doing a great job at that without them

We've got to get flussig in print! Then i need to find a willing owner of a 911 RSA to spend a day doing a controlled comparison of the two.

Going to work now. Have a great weekend Shark fans!

M. Requin

Interesting, and reminds me that when I was at SITM I promised to write to those guys. Time to put up...

xschop

Is anyone making flat panel door cards?

77tony

Rob Budd at www.classic9leatherworks.com sells 1/8" ABS door cards for the 928. T

xschop

I don't want armrests or I'd get those. Flat cards will allow a window crank mod. I also hate that I can't get to the Ebrake easily with the armrest.

The Fixer

When i have the time i'll do this too. What mechanism do you think is best to start with?

Loud exhaust:

I ordered the glasspack Jim said would quiet it down and add some back pressure.

This is what it sounds like presently, it sounds less loud when not under load.

I will document it after the bullet muffler is installed.