I looked over some of the older posts trying to find some info on superchargers, but there wasn't a whole lot, actually some negative experiences with a procharger system on a BB. Has anybody had similar or good experiences with a centrifugal super charger? (Small block) I'm running a 406SB right now, but am looking down the road. My 406 has a compression ratio that's too high for a SC, but I'm toying with the idea for a different project. It would be for a street car (69 Camaro) and have everyday drivability, no racing except toasting the ocassional Mustang. Part of the reason supercharging interests me is the altitude here in CO, 5200 ft, so normally aspirated engines are down on power. I'm thinking about a built 355 with a supercharger. I'm not a big fan of roots type blowers because I hate large humps in the hood. The stock cowl induction hood is the limit for me, no camel hump allowed. This leads me towards a procharger or paxton type centrifugal. Anybody have comments about using these on the street? How's the reliability and maintenence?

Thanks,

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Shawn Peterson
1969 Z28, 406SB
http://www.geocities.com/corsican69

I'm not sure what negative experiences you have heard of, but I am very happy with my Procharger.

Engine: 355 that started out as a ZZ3 (4- bolt block, forged steel crank), pocket ported heads, COMP blower cam, TRW blower pistons gave about a 9.4 compression ratio, balanced assembly, single plane intake, modified Holley 650 dp, MSD dist, coil, and 6AL. Dyno results were 360hp before supercharger, 506hp afterwards.

I would rebuild your 406, but detuned a little. Lower the compression to 9.0 (with aluminum heads), get a blower cam (mild anyway since they have very little overlap), and more conservative heads. Advantage over my combo: much broader torque and HP curve. You can go conservative on the heads and cam because the centrifugal supercharger will more than make up for the lack of breathing capacity on the top end. I think it would be a great street motor. My brother is building a 400 for his car and I'm trying to talk him into it.

The one thing I will admit, it is a bear tuning the combination. But, once your there, you shouldn't have any problems. My car still runs a tad rich.

I understand Holley is in the process of reengineering one of its fuel injection systems to be compatible with centrifugal superchargers. Currently, their computer reads vacuum but can't read boost. I'm not sure which system it is though, the 4dfi (looks like a 4 barrel) or the port fuel injection one. This is definately something I will buy when it comes out (and I have the $$$).

E-mail me if you have any other questions.

See if you can find any old articles of what Andy Granitelli did with 2 turbos and an '82 Camaro at El Mirage dry lake. I was there and saw it for myself. 1st. pass on 1.3 miles of dirt = 175+mph.(he drove it there and did this without a cage or fire system) I myself am partial to turbos, and just happen to have 2 fresh ones right now waiting to go on someones small-block. I'm at 5900' and know what you mean about lost hp. Turbos don't cost hp. to run. I have driven my fathers old Turboed, intercooled, 6cyl. Nissan Maxima diesel engined '82 Chevy LUV on the street here and at 10p.s.i. and 900 degrees on pyrometer, in 5th. gear at 5800rpm's = 140+mph. HeeHee.
Rick
'68 SS 427 (might Twin Turbo It?)
'66 Yenko Stinger #YS-100

[This message has been edited by YenkoYS100 (edited 01-25-2000).]

Speaking of turbos, see last months (this months?) Chevy High Performance magazine. There was a great article on turbos. Said a mild 350, single turbo, and EFI could pproduce 650hp. EFI is the key.

I have the Weiand 177 on a BB right now. The car isnt so much a daily driver but is pretty manageable as it is. The biggest consideration (past a properly built engine and carb) you will probably have to deal with is the heat. Horsepower makes heat, no way around it. Expect to go up 10-20 degrees in driving and maybe more if you see stalled traffic. As for the hood hopefully someone out there has that answer. For a BB it just wont fit even with a 4" cowl without shimming. The only real extras you will need are a large capacity fuel pump with regulator, fuel pressure gauge, new carb linkage and throttle spring (Lokar stuff is GREAT!), a drop base air cleaner (probably), some longer manifold bolts and that is all I can remember right now!!! The Weiand procharger (at least for BB) works with the stock fan setup with a 2" spacer and so your large capacity radiator and shroud will work. If you are at all heavy footed then you can kiss any tires but super soft "drag radial" types goodbye. My system heats up to about 160 in light traffic and goes slowly up when I am not moving. Spray a little and of course that goes out the window... NOTHING beats the whine... On the 540 inch 'Cuda the heat stays upwards of 210-215 while moving but that is with 8 lbs of boost on a 6-71 blower. That by definition isnt too much of a daily driver and was never intended to be. Oh, one last thing, if you have a stock style starter it probably wont last past a good heat soaking every time you drive and so be prepared to "wait it out" if you stop after driving a while.

My car has never gone over 200 degrees sitting in traffic, but then again, its not a big block.

Roots type superchargers generate more heat because they are not as efficient at moving air as a centrifugal design. Also, the big chunk of aluminum a Roots is made of does a good job of picking up and retaining heat there on top of the engine. A centrifugal unit is mounted away from the engine, so air flows around it. I'm not saying it doesn't get hot, but nothing like a Roots.

I suppose after being around 9 vehicles from VW sand rails to street thumpers featured in Turbo Magazine I have a healthy respect for turbos. I had the privelege of working with Performance Engineering in San Bernardino on projects. Including the 85 world record for hp and torque on 92 pump gas (900 hp and 1000 lb torque in a twin turbo Mazda RX7 w/injected 355). My particular project I was overseeing was the development of a Dodge Cummins/Dick Cepek/4WP 250 being done for a 4Wheeler magazine (never published due to truck owner moving-me). Changed boost from governed level of about 12 lbs to a spooled level of over 22 lbs with adjustable wastegate, sleeved and machined holset housing with iron liner, machined turbo blades for step boost control, adjusted fuel delivery curve from ajusted level of 200 to 400%, etc etc.etc. ... The truck could "yank the snot from a gorilla". My concern with my camaro was the lag in turbos that isnt found in blowers as well as the pyrometer problem due to the rpm level I primarily drive at. I have been down the spooling road many times in racing aircraft design, 4w design, street car design and yes even in an 18 speed that did 65 mph with a turboed weed eater engine. Also, nothing beats the whine... Having written that, if I was going to build a "street" motored car as described in the original post I would more than likely use a centrifugal system not just for the streetability of the system but also the hood requirements. You cant hide behind a 4+ inch hood. But if you want simple HP do the blower. For the same amount of money invested in a complete centrifugal system you can build a BIG hp motor (read= not daily driver). Just my $.02 and not meant to flame anyone. Obviously I have left details out in development etc. Just the way I have seen things.

pink68> I'll have to agree on the lag of turbos! I guess in my old age and past years of driving a fuel tanker, always at 80,000lbs, I got use to a little lag. I really like diesels and turbos(especially a 500hp. Cummins,475hp.D-Deck Detroit and an 8V92 at 500hp.) I guess the lag could be helped out with NOS or compound turbos? I think I'm getting a little strange as I think I will like 2.73 gears also? It sounds like you got to do alot of neat projects with all kinds of different vehicles!!
Rick

shawn, i had a B&M blower on my 327 in my 68 camaro that was driven every day. it fit under my stock cowl induction hood, i never had any troubles with it over heating and as long as i stayed out of it, i even got good gas mileage. the only problem i ever had with it was with the idler pulley setup. i used the front pulley, on the blower, for a 400ci, which made the blower give me a little more boost. buti all in all, i had good luck with it and i didn't loose to many races with it.
just thought i'd let you know.
good luck,
bruce69camaro