408 dyno results

Mike, nice numbers. You should have taken it to 7K though. Boy those heads look good

Just guessing, but you might have gained 50 just by going injected...if not more.

Thanks Mike. I was glad to help.


George S, it has Hilborn EFI.

John

Very nice! The Hilborn manifolds always look impressive.

Johnny

Nice numbers! What was the torque curve like? How did the CHI's flow? Were they modified or stock?
Will

Thats awesome! Well done sir.

Jb,
I know it has them. I meant because of them is a greater HP increase over a carb. Just wonder how much of an increase.

Thank you all for the kind words, it was a long process with lots of help from some talented car
guys.
To answer a few questions; the torque curve was
340ft lbs @ 3k rpm to 428ft lbs at 5.5K rpm @ the rearwheels.( the graph I got was from 3k rpm to 7K rpm only)
The CHI-4V were ported and the exhaust ports exit widened and then port matched to the Hilborn intake. Because of the higher flow numbers ( couldn't find the paperwork from the machine shop, but remember somthing in the high 300's.) which is why I went with a custom ground hyd roller cam from Isky. Those numbers were 621 lift int. and 631 lift exh with 298int and 302 exh duration. We went with 110 lobe seperation to help bleed off the 10:6-1 comprerssion so it wouldn't rattle ( which it doesn't at 36 degrees total advance) What was surprising is the lack of cam lope, which I'm told is from the tall Hilborn stacks. It sounds real good but nothing like you would expect from a cam that big.
I was told to put a couple humdred miles on the engine and bring the car back to Superior for additional tuning. They expect bigger numbers
especially if they can rev it closer to 7K rpm. I'm not convinced ( hesitant really ) that I should to do that. It's too bad that I've built a motor that makes a ton of horsepower between
5,500 and 7,000 rpm and is in a block that can't take much of that. Oh well, it sure sounds good and I know its there on occassion. Also, I have a bunch of good parts that will be posted for sale soon, including excellent closed chamber 4V heads, crane hyd roller cam, P&J's quiet gear drive,and 6 childs & albert rods with carillo (sp?)flat top pistons for a stoker.I'll try to get those posted in the next couple of weeks.

quote:

Just guessing, but you might have gained 50 just by going injected...if not more.

From what I understand, carbed motors develope more HP. EFI offers drivability.
Will

...Highly Impressive!! Good Work! I'am Happy I could be a small part of it! You did a great job of matching all the right parts! Congrats!

FWIW. It's My understanding that Carbs Produce More Torque, and Fuel Injection More HorsePower. Ofcourse, there are Exceptions.
Beautiful Engine and Bay!! Your Whole Machine is Well Done! A real Pleasure to see it!

I would imagine any differences in HP or torque would purely come from manifold designs of carb vs EFI manifolds and their airflow characteristics. I hardly think the engine cares where its fuel comes from. Benefits of EFI would be a much higher resolution of fuel delivery for various engine conditions. If equipped with a system to control spark it could also free up some power in some areas as well.

Mike your motor sure is pretty, good job, congrats on the results.

Advantages of Fuel Injection compared to Carburetors from a performance perspective:

(1) Better fuel atomization at low engine speeds. About 15% more torque & BHP below 2000 rpm, lessens or eliminates cylinder washing.

(2) Port injection offers better fuel distribution over a single four barrel carburetor when used with a common plenum manifold. This is not an advantage with independent runner systems.

(3) Not affected by G-Forces during acceleration, braking and cornering. Fuel sloshing in the fuel bowl of a carburetor affects the carburetor worse and worse as G forces rise.

(4) Not affected by rough terrain (off-road racing)

(5) No reversion, which has been a stumbling block for engine builders installing independent runner systems employing carburetors.

(6) Easier to design torque enhancing long runner intake manifolds for fuel injection. The tightly curled manifolds that are so common today would not work with carburetors. The fuel mixed with the air by a carburetor mounted on the inlet of such a manifold would be thrown out of suspension by centrifugal force.

(7) Tuning with a lap-top is faster than changing jets.

-G

Nice to see you ended up with Jeffs car (now yours)...that puppy looks nice and pulls well too : http://www.poca.com/index.php/...g2_imageViewsIndex=1

Thanks Does 200, I actually bought the car from a guy in Bonsall, who bought it from Jeff.
When I had some questions about the car I called Jeff and he was very helpful. He also put
together an album of enerything done to the car since the early 80's!!

Hello Mike.............. very nice ride, If you are running electronic injection make sure the shop gives you a copy the latest configuration file on a USB drive. Having it could be of big help down the road. If you don't mind me asking, how did you mount the front Air Dam on your car. It looks removable to me. If so, it must make getting the car on a trailer alot easier? How is it mounted ?

Regards............ Doug.H #6434

Hi Doug,

I ended up taking the air dam off as it was hitting eveything. Worse yet, I have an inclined driveway and there wasan't any way
to get in or out without scraping the front.
It bolts right to the front of the car, so it comes off pretty easy.
I recently bought a smaller metal spolier from P.I. Motorsports and am in the process of putting that on as we speak.