• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

The Dyno Tells All

Share this page

I don't know about the Dynapacks, but I do know that the numbers from a Mustang Dyno can (and usually are) corrected to a standard temperature and pressure so that you are talking apples:apples when comparing.
 
The closest Dynapack machine to me is on the north side of Houston, Texas. About a 5+ hour run. Guess my car would be nice and warmed up by the time I got there. Anyway, the interesting part is they told me I could get accurate readings as far as horsepower at a variety of rpm's, wouldn't necessarily have to redline the engine. Interesting.
 
First let me say that those are very good numbers, and no need to be disappointed!

Good point about comparing figures from different types of dyno; it should not be done, personally I prefer Dynojet numbers to Mustang because you have to estimate your cars weight and know the gearing for the Mustang, seems likely to give less consistent numbers. The Mustang is really a device used to predict 1/4 mile times for drag racers, in my view.

It seems you have gained 10-12ft.lbs of torque but about 25 bhp. compared with stock, a big improvement. The race guys seem to favour a/f ratios around 12.5-13, which sounds rich, but empirically gives best results. (This info from Jack Drews, and stated as a fact, not an opinion.)

It would be my guess that this is about 145bhp. at the clutch, any further mods are going to result in very small gains for large amounts of money.
Simon.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]What sort of dyno -[/QUOTE]

Alan,

See this for Dyno info: Dyno Day 2007
 
Trick6 - have you seen where alan atkinson posted ~ 160 hp when his 73 was running triple strombergs? Looks like you both had/have similar setups.(???)
 
simpson said:
Trick6 - have you seen where alan atkinson posted ~ 160 hp when his 73 was running triple strombergs? Looks like you both had/have similar setups.(???)
Click to expand...
Nope. I have not seen that post. I sure would like to know more about the 160 hp number.
I did see his car over a year ago when it was in a Milford CT shop with the 3x175s on it. I finally met Alan this year at the British by the Sea in Waterford CT. His new FI system looks great. Funny you would know a car before meeting its owner.
I do have to take a little credit that I had tuned my car by feel to the best hp confimred on the dyno. While on the dyno, we made changes seraching for more hp and went back to my tune up where the most power was found. I think that I have extracted as much hp as I can with the present GP2 cam.
Rick Patton's SCFI TR6 is a beast with a screaming 190 hp and 200 ft lbs of torque. He offered me the wheel when I vistited him and I said no thanks. I did not want to come home to 118 hp knowing what 190 felt like. Riding shot gun was bad enough. What a kick in the butt 200 ft lbs produces. WHEW! Can't get that on carbs.
 
Alan:
120-125 hp AT THE REAR WHEELS is what I was hoping for. That is 7 more than I have been able to develop. I believe that would be a very noticeable power increase for me.
 
Well you're not really comparing the same thing.
My numbers are from a Mustang, yours from a Dynapack.
hp numbers differ between dyno types.

I'll leave it to you to do the google search for comparisons as to what people rate them relative one to another.

Obsessing about a difference like that is futile.
Regardless of what the numbers say, the performance either is enough or it isn't. You have a good 50% bump over stock.

If it is. Then you are all set.
If it isn't then you need to spend more $...
 
Alan:
No more money is doing into this motor. There is plenty of power as long as I don't jump on a V8. The low and mid range is very stout. It cruises very nicely with plenty of passing power. Surprisingly good gas mileage. I was looking for a little more power but it is what it is.
The next power modification will be an Ecotec.
The link below takes you to my dyno chart placed by you. Thanks

https://www.6-pack.org/spaw/dyno/AlHP.pdf
 
Yes I have checked the timing with a light and I am at 12 degrees. I use the light to record where I am so that when I do work that disturbs things I can go back to home base. Well, I guess you can say I set the timing by ear. I advance it until it pings and then back off until it stops. That has been my mad method for years.
 
My initial method consists of running the engine at 2500rpm and setting the time where the engine sounds the best, then adjust for pinging if necessary.

What compression are you running?

-s
 
My combustion chambers are sized at 44 cc's. That totals about 9.98:1 cr. The motor is 0.030 over and has been balanced. There is a list of components on the link below.

I have since installed the Blind Moose rear shock conversion with the KYB shocks. I love the way it handles with this set up. The ride is a bit stiff but comfortable.
 
Trick6 said:
Alan:
120-125 hp AT THE REAR WHEELS is what I was hoping for. That is 7 more than I have been able to develop. I believe that would be a very noticeable power increase for me.
Click to expand...

Your Dyno results state about 118 HP at the flywheel. What did the guy say that it translates to at the rear wheels? Isn't HP always higher at the flywheel in Dyno results?

.
 
Al,

Your setup is pretty close to what I had. I'm running right at 10:1 with a GP2, and roller rockers. I did have triple ZS carbs, but I got rid of them in favor of dual HS8's. Tuning two carbs is so much easier than three. I think I've finally got the new carbs setup the way I want them, so I'll be putting the 6 on a dyno as soon as I can make the time. I'll be interested to see the difference. The shop I've been talking to has a DynoJet.

Interesting information on the a/f mixture; usually somewhere in the 13's is the sweet spot. I'll have the keep that in mind when I get mine dyno'd.

Take care,
-s
 
I know that the sheet says flywheel, but this is a rear wheel read out. NOT FLYWHEEL. The dyno is connected directly to the car replacing the wheels.

Normal advertised hp ratings are flywheel measurements. There is a 15 to 18% hp loss from flywheel thur the drive train to the rear wheels.
 
Interesting about the afr. I tuned the motor, carb and timing, by drive feel and plug reading. The dyno 02 sensor reported me running a rich which surprised me. I tweaked the carbs to lean it targeting the high 12s mid 13s and lost 10 hp. I returned the needles close to where I had it. As you can see, at WOT, I am 11.25 to 12.25 afr. This is where I develop the most hp and BTW, where it “feels” best. Notice that the afr curve was on its way up at 5200rpm shut down. I noticed this with the hp and torque curves also.

https://www.6-pack.org/spaw/dyno/AlAFR.pdf

Now this is rich to me but the motor likes the gas, and likes the timing. We cannot over look the 125 ftlbs of torque. I think that is impressive.
 
Back
Top