DiscoQuinn

I've got a pair of Pontiac Bonneville SSE super chargers sitting in my lap right now. One of them should make it's way to my race car.

I am a skilled fabricator, but the technical knowledge of engines performance needs is something I lack in. Please inform me.

The case: Stock, unported 12a. Nikki actually fell apart at the lack track day, time to make changes.

Problems: Fueling considerations, and setup difficulties for super charger setup.

My plan: Affix the super charger onto the stock 12a intake manifold. Run a draw-through Holley, Edelbrock or other Carb.

Questions:

#1. What size carb will I need?

Through my calculations the stock 12a flows about 450cfm, with the super charger, the fueling should need an increase. I am looking at 600cfm options, but I am unsure if that is too larger for an unported 12a.

#2. Will my current aftermarket electric pump supply enough fuel?

Currently on a Mr.Gasket electric carb pump. I feel it should flow enough fuel to complete the job, however, I am unsure in total.

#3. Is there a specific fuel pressure regulator, or style of one, I should be looking for?

My current one is inadequate, looking for an affordable, but decent upgrade.

#4. Will fuel running through my EFI OEM charger destroy it?

#5. What questions should I be asking?

Thank you!

t_g_farrell

iTrader: (1)

1. I think your close with 600. Jetting will be the key.
2. The stock fuel pump will not be adequate, it barely feeds the Nikki and can't even feed a large
weber appropriately.
3. You may want to get a rising rate regulator based on vacuum to keep the fuel level consistent
in the carb.
4. Is the SC designed to be a drawthru with fuel running thru it? Thats the question.

I've seen folks toy with the Tbird SC on rotaries but not the GM ones.

My answers are best guesses and not from experience.

broken_apex

iTrader: (1)

Check these sites out. They may answer a lot of your questions.

Install Info

Supercharger CFM chart

PercentSevenC

1. One of the popular misconceptions about carburetors is that you can calculate one ideal size for an engine. You can't. 600 sounds like a reasonable start, though, assuming you're keeping it mild.

2. No. Get a big Carter or Holley pump.

3. Doesn't matter a whole lot as long as it will supply the carb with enough fuel at the right pressure. We've always used the cheap Holley regs with Camden superchargers, but a Mallory 4309 or similar set up with a return would flow better. I advise against vacuum-referencing the pressure reg, as tuning it would be a headache of epic proportions.

4. Probably, unless it has gasoline-appropriate seals. As far as I know, most EFI-style blowers don't.

5. Questions about boost levels, compressor maps, ignition timing (and probably ignition upgrades as well), safe AFRs, etc. You may want to look into water injection as well.

Since you're going through the trouble of fabbing up an intake, why not blow-through instead? Far better to use an intercooler if you can.

j9fd3s

iTrader: (3)

1. i agree, it should do about 450cfm/235hp at the engine give or take. so a 600cfm carb is a great choice. going to a 750 carb should add about 4hp....

2. you need more than 200 gallons per hour at the engine. so stock pump is about half of that...

3. the Mr Gasket one is supposed to suck, the holley one does suck, if i have to buy another i'd spend the $$ and get the mallory, it looks like it might fit easier/better (if had to do fuel pump again, i'd get an external walbro, it looks like it'll fit exactly like stock, unlike the POS carter)

4. no idea, but the magic 8 ball says it doesn't look good

5. air/fuel should be rich, like 10.5:1 to 11. timing should be verified, and be set to 10-12BTDC Leading, i like a 15 degree split, and this is what Mazda chooses too. if you misfire at 10.5:1 AFR it needs stronger ignition, not a leaner mixture. exhaust should be as free flowing as you can get it, it would be a good idea to hook a pressure gauge to the exhaust so you can see backpressure.

85rotarypower

IIRC the Eaton M90 supercharger used on the Bonneville is pretty much the same unit as used on the Thunderbird so any info on the Ford setup can most likely be transfered to the GM version.

Mazda RX-7 EFINI TYPE

Why not just do a custom EFI setup and run a megasquirt? :P

DiscoQuinn

I'm just not interested in EFI at this point. It's more likely a better option for my super charger, I agree.

Nicholas P.

iTrader: (1)

Camden SuperChargers - Get a Supercharger kit for you're Mazda Rx7 13B Rotary

Camden SuperChargers - Get a Supercharger kit for you're Mazda Rx7 13B Rotary

A good read on superchargers for the 12A

rexrecycle2

I had an Eaton 'charger on a stock 12a 20 years ago. Use the best pressure reg you can get. I used 3/8's fuel line from the tank. Modified the throttle body area to accept a Holley carb. and used a 750 double pumper. Free flowing exhaust on a Racing Beat header. Biggest problem I had was blowing the power valves in the carb., best to remove the power valve (with kit) and use bigger jets in the secondary. The pulleys were the highest overdrive Ford had at the time and it would make 9.5-10 lbs of boost. Used the stock ignition, but made the vacuum advance work backwards, retarding on boost to about 12 degrees. Never dyno-ed it but made good torque right off the line and would smoke Z-28s. Made a fun track car too.

Rex

PercentSevenC

Mind elaborating on this? How did you hook it up?

theNeanderthol

iTrader: (1)

^^^ +1 I'd love to know how you did that. I've thought of doing it for a while. Seems like a cool elegant solution to retard timing mechanically.