Whats a good way to Upgrade a 3lt SC?

[slow car]

Hi ,
Now the end of race season is here ,i am wanting to freshen up and maybe up spec my 83 3lt row SC running 40 webers,964 cams, programmable MSD dist and 1,1/2" tuned headers into straight through resonators. Approx 275 HP at flywheel.Running 98 Octane fuel.

Would like to get 320 usable Hp?
What options have i got without changing to twin plug and still keeping the 40mm webers if possible?

Going to 98mm with 10.5 and a cam/porting ?
Any real life success story's and how to,s would be great?
The car is used for Road racing ,autocross,and track days, so need a all round motor.
Not used as a street car.
Thanks for any help.
John

[rkeele]

Hmmm 275 hp from a 3.0 with webers 964 cams and 1.5 headers wow, my 3.0 with webers 911E cams,headers head work could not make near that, turbo it?supercharge it? seriously to make that kind of power would take a lot of $$$$ in my case I sold the motor and installed a 3.6 problem over.

[turborat]

Originally Posted by slow car

Hi ,
Now the end of race season is here ,i am wanting to freshen up and maybe up spec my 83 3lt row SC running 40 webers,964 cams, programmable MSD dist and 1,1/2" tuned headers into straight through resonators. Approx 275 HP at flywheel.Running 98 Octane fuel.

Would like to get 320 usable Hp?
What options have i got wiincluding nging to twin plug and still keeping the 40mm webers if possible?

Going to 98mm with 10.5 and a cam/porting ?
Any real life success story's and how to,s would be great?
The car is used for Road racing ,autocross,and track days, so need a all round motor.
Not used as a street car.
Thanks for any help.
John

John, I think your current HP Number is optimistic. I suspect the rear wheel number is more like 200 - 210. 320 HP will cost north of $30k and be a hand grenade. And it will have to run on race fuel. My '79 big valve 3.0l is 250 at the wheels. It's punched out to 3.2l. 9.5:1 compression pistons. GE 600 Cams, stiffer race valve springs, PMO 50 Carbs dyno tuned and properly jetted. That's a $10k build including machined heads for second plug. Add $$$ for PMO carbs and twin plug ignition parts. This build is probably tje limit of pump gas and OE connecting rods. You may also need '78 or '79 big valve heads.

[333pg333]

He did say at the f/weel, not rears.

[turborat]

Originally Posted by 333pg333

He did say at the f/weel, not rears.

K. Add about 12% to the RWHP number. The motor described by the OP is making no more than 220 at the FW. A very generous 220 HP.

[cstreit]

No replacement for displacement!

Look into 100mm or 102mm kits...

[Eagledriver]

Originally Posted by turborat

K. Add about 12% to the RWHP number. The motor described by the OP is making no more than 220 at the FW. A very generous 220 HP.

While I agree that the OP probably is a little optimistic, the motor described could easily make 230 at the wheels (mine does with stock SC cams).

-Andy

[rkeele]

Dyno numbers can be all over the place, when was the last time the dyno was calibrated? Mustang dyno? or Dynojet? can give different numbers, I have a friend who got a 290rwhp number from a stock 964 no chip or headers I can easily pass him on any track with my 964 motor dynoed at 270rwhp with chip and headers. That been said believe whatever you want and have fun.

[j911brick]

Before knowing what direction to lead you, we would have to know what direction you are going. You mention racing, but you don't mention what class/club you are racing.