John..

This is one of the first of a string of many to come updates on this 4.5 liter conversion I am working out...

I have the engine up on the stand, I am still waiting for the US top side to come...the one that I traded the complete Euro CIS and induction system for.

I have basically narrowed down the location of the components and style of manifolding to be used. I am purchasing the materials to make the manifolds today and this week. Have to get with some laser shops on the flanges and the like.

Engineering on the parts has started, this includes most of the flanges that will need to be cut to support the manifolds. Bell Engineering will do the intercooler fabrication.

I have the turbo and am sizing it for use on the engine. This is a very nice Garrett Hybrid unit that has a nice steep surge line, highly efficient cold side and is available in 4 different A/Rs on the turbine side. It can flow nearly 1000 cfm...about large enough to blow out 600 crank HP, possibly more. The nice part is this car will use it in the sweet spot of the efficiency, well over 73% with a peak of 76%

This car will get a simple and highly efficient air to air intercooler and the top side will look stock with the exception of a couple of sneaky pipes to and fro the air cleaner and throttle body. It will retain the look of the already nice looking 928 engine bay. The stock aircleaner will be retained.

Keep in mind with all of this centrifugal supercharger talk on here that the turbo conversion will offer many significant advantages, including the following:

More streetability, no need to throttle while crusing at moderate RPM. i.e. no boost when you don't want boost.

Higher efficiency setup, minimal parasitic draw, no loads on the nose of the crankshaft.

Boost based on load, not just as a function of RPM

Significantly more area under the curve, face it you have to shift it at the redline anyway.

More to come soon....

Randy V

C'mon John - sure we're interested, but do we really need almost-daily updates?

Jadz928

I find John's developmental information very interesting, and hope he will keep us updated as often as he feels inspired. He is doing some excellent stuff here, and I hope he enjoys the support of our 928 community.

As far as stating the benefits of turbo construction, or the pros/cons comparison to SC'ing, I'm hoping he could save that for another thread, or a later time. There is plenting of that info in the archives anyway. Plus it could undermine the developmental sharing of info in this thread.

bcdavis

The whole dyno battle and SC/TC debate is a whole different discussion.

There are obviously people interested in hearing about John's turbo development...

drnick

yes we are interested. i imagine john will be able to manufacture duplicate manifolds for his turbo setup which could assist others to boost by this method. are there engine internal mods planned?

Old & New

It's O.K., but just mental masturbation until he offers a kit... the details are only academic to most unless they are actually choosing between two available products!

And until a dyno chart is posted or a quarter mile is logged, it's *extremely* academic.


addendum:

Don't get me wrong, John; I also applaud your efforts! I just want to gently nip at your heels toward producing a kit... a tangible way to benefit the 928 community.

mspiegle

Even though i run Andy's kit, i am very interested in the turbo setup and any info you have to provide. Nice work ! Show those turbo-badmouthing people that you mean business.

Steven Ko

I hate to get involved in this thing at all, but isn't this a forum? A place to bounce ideas off of each other freely and share in discussion? I understand that some people will like his updates and some won't, but either way, I don't think we ought to be telling him how frequently he can post. I understand moderation when there is something offensive or something that may hurt the community, but he is doing neither here as far as I can tell. If you don't have interest in his daily postings then don't click on them. I love this forum because of the open discussions. I hope it stays that way. OK, sorry sorry, off my soap box!!

Keep the updates coming!! Call me officially biased because I for one will probably never slap a turbo or supercharger on my car but I love innovation and applaude those willing going out on a limb. You might even argue that those type of people are part of the reason we can drive a 928 today. Oops sorry got on that box again....

bcdavis

I'd like to compare a s4 turbo kit, to an s4 supercharger kit, both with the same boost and power goals in mind...

PorKen

I vote for a small clutched supercharger (Mercedes SLK), backed up with a single large turbo, and a big-**** intercooler!

No torque curve, just a straight line from 1000-6000!

Old & New

Ken,

You ought to be able to crank something out of your Monster Garage...!

John..

I just returned from the supply store and have 60% of what I will need to construct the primary manifolds. No comments on their shape, sizo or style until I am done, but they will be simple and very effective.

Don't worry, I won't over-post, as I have lots of work to do on this project along the way. Randy, you must just not like my space blanket under the hood.

Trust me, the Autocad has been working hard, and this process will be totally documented, the beauty of having a clean sheet of paper.

I have all of the knowledge from last year's project to put into this setup and then some. Time will tell, but my gut tells me there will be a good lesson in forced induction when all this is done.

Randy V

Red UFO

John..

I don't mind updates. Keep posting and make sure to post pics too! Eventually I'll get into this down the road so this is great data for the archives!!!

bcdavis

Stephen Ko, I agree with you 110%.

A forum should be an open thing, free for people to share ideas.

If people do not care about a car for sale, or a turbo kit, then don't click on the posting.