My 521 dyno data

[John Owen]

The posts on this and other forums convinced me to try and keep the Victor manifold on my 514 crate motor, so I at the least owe you a report on the results. Stock inside, sequential DFI, 2000 cfm throttle body. Here is a photo:

And here is a dyno sheet. Tuning session was to generate a basic volumetric efficiency map, and this was the last run, as close to driving conditions as practical, hood closed:

Again, thanks to all

[Tom Wells]

WTG John!

Really nice numbers

Tom

[Naja]

John -
Looks great.
I have a similar engine that I have only done an engine dyno on, so I'm not sure about the differences in the curves that the drivetrain might generate. My torque curve was quite flat from the initial logging point (2600 rpm) to its peak at 4700 rpm. I have about the same setup as Tom, but I got significantly higher numbers (both hp and fp) - again, I don't have a good feel for a reasonable correction factor between types of dyno tests (except that it could be anywhere from 15 to 100 hp difference).
The people who set up my engine and did the dyno felt that the Torker II manifold was a significant restriction to airflow, and, hence, performance (and I agree). We all felt that if I were able to put a Victor Jr. manifold on the engine, we would have gotten around 700 fp and 600-650 hp.
I have had discussions with others about their injector sizing. I am using 65 lb. injectors and have a 60% Duty Cycle at the maximum performance point. Considering the restricted air flow, I feel that I would have hit the target of 80% Duty Cylce with a Victor manifold, like yours. This raises the question: What size injectors are you using? Tom and Steven (Back In Black) are using 36 lb. I feel that their engines are not realizing their potential because of undersized injectors. I feel that 48 lb. would be about right for our setups. (I'll keep the 65s because I may go to something that will utilize them in a couple of years). With your Victor manifold, I feel that 65 lb. injectors are necessary for you to get the most out of your engine and not run to close to 100% Duty Cycle and fry the injectors.
I would be interested in your comments.
Regards,
Frank Newman

[John Owen]

Hi Frank -
The usual hp and torque loss range for the drivetrain is 15-20%, with automatics losing more than manual. Assuming a 17% loss for my setup, 503 rear wheel is about 605HP at the flywheel, and about what the motor should produce. I have 55# injectors, but failed to note the duty cycle - sounds like I need to take a road trip with the computer hooked up, just hard to drive and play with the computer. I think my loss with a Torker II would be in the 100HP range because I kept the solid roller cam which is at the upper range for street use and needs good higher RPM flow to make power.
As to traction, I use BFG TA/KD 275 17 on the rear and they behave very well on dry pavement. In 1st or 2nd the tires can be broken loose at most any speed without using the clutch, but the tires never just go up in smoke- back off a little and they regain grip quickly. In 3rd they begin to slip a little at the high end of the power band but still accelerate strongly. No problems in 4th or 5th. Wet roads are a challenge.

[ToyCollector]

It has been about 60 days that I am now Cobraless...these pictures make me beg you for a ride! Very well done!

[Jahred]

John, those numbers, I guess this is obvious........are at the wheel/hub??

Did you actually test any other manifolds?

How does the Victor Perform at lower end of the range?? Driveability.

I'm curious. I had lots of folks talking me into a Performer type manifold. I saw some charts once I think in a Champion auto catalog that seemed to suggest better torque at much lower RPMs.......I ended up with a A.T. Francis.........pretty happy with driveabilty et al.......

Did you have any chance to do any dyno testing or get any direct feedback on Victor vs Performer type....??

Have the Victor and a spare 514 sitting around for next project.........so I am curious.

[GB]

John,
Beautiful car, I was amazed at all the technology you have put into your car. For those who have not seen the car, the dash and electrical system look like something out of Star Trek. Keep up the great work.

One other thing, try parking a little farther away from me at the next cruise-in, your making me and my car jealous. Seriously, nice to meet you and I look forward to seeing you and your car again.

Greg

[Mr.Fixit]

If you are going FI, then a single plane manifold will be better, usually.

[stengun]

Howdy,

Hey dude, you ran out of cam, heads or something. You only put out about 20 hp more at 6,000rpm's that you put out at 5,000rpm's. Car would be faster if you shifted at about 5,300 t0 5,500rpm's.

[Lubrecon]

You don't shift on a dyno pull!

[John Owen]

Just a brief update - I changed to the SCJ heads, the HP profile is almost identical in shape at rpm, but adds a little HP at low revs and now peaks at 553 RWHP, or about 660 at the flywheel. Single disk clutch started slipping badly, so I changed to a dual-disk, works great and holds.
I also compared breathers while at the dyno. The homemade box produces 25 HP more than the Ford oval with Ford filter.
As to the flat HP peak, that is a great benefit of big motors. Like Lubrecon said, you don't shift on a dyno, all 4th gear, but when the time comes - Shift at 6500, if gearing drops the revs 1700, you still have near peak HP. Fastest acceleration is achieved by maintaining the highest average HP to the wheels, within the limits of traction.
Hope the information is useful.

[Jahred]

John..........what clutch set up were you using before and after the change.......is the double disk street friendly?