bd0nalds0n

Which version of his intake manifold do you have? I have a two piece version--it's an upper casting that's three dimensional (it has the "sides" built onto it) and a bottom plate. There are three piece versions out there too.

I had a local shop build me a thicker bottom plate (with intercooler cove). I also had them build me a thicker bottom plate without the cove. Somewhere on this thread I posted prices of what they were willing to create extras for. It wasn't cheap, but it will cost a lot less in time and energy than recreating it yourself.

https://rennlist.com/forums/928-foru...nd-prices.html

$300 for a flat plate, $1100 if you want the intercooler cove.

victor25

Hey Brian.... My manifold is a solid cast upper piece. I may be interested in the flat plate. Can you do 3/16 or 1/4 instead of 5/16? The other is a little pricy and besides I could always turn it into a cove version myself later when I get more power hungry.
I was looking for drawings because the shop next to mine is a laser cutting shop. They will cut it for free for me if I supply the data. I was going to use 3/16 steal (they cant laser alluminum).

bd0nalds0n

I'm sure they could do whatever thickness you want. Frankly, I don't think the cost is in the material. It worked out to be more time intensive than they originally planned. So one way to make up the time is by charging comparatively more to anyone else who doesn't want the aggravation of recreating it themselves. Then everyone wins.

PM me the thickness you want and what you think is a fair price, and I'll ask the machinist. The worst they can say is no, or counter.

Vlocity

Hey Guys,

I'm starting to make my off season list of things to do and one of them is to explore going to the 10PSI range. I'm currently getting about 8.5 PSI out of a 2.5 inch upper pulley and the standard Keel kit lower.

My supercharger is the 420 Autorotor. Has anyone out there went to the 10PSI range with this set up? I am guessing that I need to go to about a 2.25 inch since the change from a 2.75 inch to 2.5 inch pulley changed the pressure from approximately 7 to 8.5. The follow up question of course is whether or not the 2.25 would have enough wrap to work (I'm using an 8 rib pulley now instead of a 6) and if that RPM would exceed the design of the Autorotor.

Your help is greatly appreciated.

Ken

dprantl

Well, I am running a 6-rib 2.25" upper with my M112 and I haven't detected any belt slip. This puts me at ~8.5psi. Typical max RPM numbers are ~15k RPM for the older eatons, not sure what they are for the Autorotors. That puts my setup right at the limit @ 6,800RPM with Andy's original 5" lower pulley.

Dan
'91 928GT S/C 475hp/460lb.ft

blau928

Autorotor MX 417-424 compressor recommended max is 15,000 RPM.. Using a 2.25 Upper, and a 5.0 lower gives you a pulley ratio of 2.22:1 With such a small pulley, I would be concerned with belt slip unless you are running 8-10 ribs, and have more than 220 Degrees of belt wrap..

Others may not be...

However, You might be better off making the intake restriction to the SC less, and not having it work as much than going with a smaller pulley.... You might be really surprised what it does for you.. You don't need more pressure, just more air....

Just my $0.02....

Rick Carter

I will soon have a ST1, if you'd like to come down and tune on the dyno here let me know.

Vlocity

I have a very unrestricted inlet, there are numerous pictures in the thread of my 975 CFM 4 inch diameter filter, cold air pickup and 4 inch tube all the way to the MAF. I don't think I can optimize this any more than I have.

Rick, That is awesome news !

John Kuhn did my tuning last spring and I went to a Bosch racing pump, larger lines from the fuel tank, a custom fuel pickup and then 36 Pound injectors.
We also put in a 2 bar GM sensor. I also have the "Vampire" unit with a knock sensor, so my base on the engine is pretty well sorted.

It looks like I will need to start looking in ernest for a pulley. I really may consider having a new lower pulley made rather than going too small on the upper, but I've had no issues with the 8 rib.

Keep in touch and let me know when your tuner arrives.

Ken

John Speake

It will be in the post this afternoon :-)

Rick Carter

blau928

Ken,

I have not seen your setup, so maybe the comment was not in correct context. most of the Keel kits used to have the filter sitting under the hood near the passenger fenderwell, and it would suck in hot air, and also be restrictive. If you have resolved this, then you are on the right track.

Go with the bigger lower pulley would be my suggestion, and also intercool the charge if you have not already done so (Or run it a bit richer to heep the charge temp down..).

Which TB are you using..? Is it stock..?

Vlocity

I don't want to repost everything...it's in the thread.

But here is the basic setup and the filter that I am using.

You will note in the photo the very large heat exchanger for the intercooler that is in the AC condensor location. I have maximized that as well.

I am using a stock throttle body with one of John Speake's SuperMaf's.

Still looking for information on a 2.25 inch upper pulley.

Regards,

Ken

blau928

Hi Ken,

Thanks for the effort and repost of the pic. Kenne Bell in Rancho Cucamonga CA may have a 2.25 pulley that they can sell you. However, I would not advise a pulley that small, as I think the belt will slip. The big front heat exchanger of the AWIC is good for thermal storage, but the AWIC core total water capacity, and flow rate of the coolant will be much more important.

I discussed this at length with the Autorotor/Opcon/Laminova engineers. For the MX420, (granted I am not sure what the thermal rating of your AWIC core is..) using laminova cores (90+ % efficiency) you would need 4-5 gallons of water in the system, and a flow rate of 40 Liters/minute flow rate through the cores. (Not sure how big your coolant resirvoir is, nor the flowrate of the pump..)

Please don't take the questions I ask as a bother, or that I am trying to lecture you. I am just trying to help, as I have done quite a bit of research on the TS setup, and went through the trouble to be an Opcon dealer to gain access to the Aurorotor and Laminova engineers. (This was before Andy Keel built any of the kits...)

Anyway, the stock 928 TB may still have a bit of a restriction to the compressor inlet at 975 CFM. 0hg restriction on an inlet tract that supports MX420-424 would require about 1800-2000 CFM inlet, and a 1700 CFM Throttle body to take into account the turns in the intake pipes, and the MAF etc.

My setup will look like this (pics below)...

Thanks for sharing, hope the comments help your solution..

Cheers

euro cobra

Hi Ken,

I checked out the video in your sig - Good Driving!!! I do have a quick question: What tool(s) do you use to change out your upper pulley? How easy or difficult is it to get it changed? I am asking because I have a very similar blower and I find it quite difficult to use the spanner wrench and rachet driven torx/allen socket to loosesn the bolt even with two people. Do you use an impact wrench at all? Please share a tip or two regarding your technique.

Ray
http://s306.photobucket.com/albums/n...view=slideshow

Hear my twin screw scream:

Imo000

Is " Some slight flaking of the coating on the rotors, does not indicate any damage though, happens as they get older. " normal for the M112? I might be able to get my hands on this one for cheap, but if it's usefull.