Dyno Run 3-2-13

wsa111

wsa111

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Put my mustang on the rollers this morning.
Temperature 50 deg. F.
Elevation 40' above sea level.
Best run was 139.32 HP Torque 151.36.
Could have been a little richer A/F was 13.1-13.4
DynoRun3-2-13Custom_zpse411aefa.jpg
 
Funky Cricket":zyn9sp28 said:
+20% for C4 155 ish, either way, that's not bad at all. thanks for posting.
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No way. Absolutely with out doubt, its not that small. That engine is lots more powerfull than that. Beware of the torque converter verses counterweight factor, often +42% to +63%. Its more pronounced on an I6 than a even a V8.


xctasy":zyn9sp28 said:
you have to realise that automatic transmission flywheel to rear wheel hp drop is not proportional to manual transmission loss.

Many, many tests have been done which cover off the factors, but suffice to say, torque converter stall and axle raatio and heast factor on dynos, as well as dyno type, alter the amount. Sometimes, bolting on 25% of power via a header or combined header and carb swap won't yield consistant results as with a manual transmission.

I have heaps of old dynamometer runs from an Australian car magazine, and automatics go off the scale in poor repeatability, while manual transmissions are very much aligned. The SAE Net veses SAE wheel hp readings are not repatable for most automatics. When you up the power into the engine, you can't be assured the gain is due to the power gain, or is being soaked up by the trans.

See http://www.popularhotrodding.com/tech/1 ... converter/

It's really important to note that a chassis dyno is not the best tool for evaluating converter performance, simply because it treats all cars as if they weighed the same. (The dyno's inertial roller drum acts as a proxy for the mass of the car, and is usually much less.) We do not want to convey the idea that a larger converter is always going to be better. It may be for some cars, but it really is an individual thing. In our case, our initial chassis dyno numbers were so far off from our engine dyno numbers, that most likely any tightening would've shown an improvement at the wheels, and that's why we did it before hitting the track. Another point we want to make is that our Laguna is on the extremely heavy side at 3,900 pounds (and that's a conservative estimate). At race weight with driver, it's looking more like 4,100 pounds. Our looser, 245mm converter would be right at home in something like our 3,660-pound '68 Chevelle. Said another way, the same converter when put into two different cars with two different engines will behave in completely different ways.

Read more: http://www.popularhotrodding.com/tech/1 ... z2KfbsrrP4
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Generally, if the dyno is calibrated, and you have 225 section tires and a 7.5 to 7.875" diff with a T5 in third, with the torque multiplication factored out, you'd get a 26.4% power drop from SAE Net to rear wheel hp.In Aussie Fords, the 221.3 hp, 165 kw 5.0 would go down to 175 rwhp. This is in line with the Ak Miller tests of old, where the rear wheel hp of 65 would have been about 82 hp net installed. The 120 hp factory rating was SAE gross, a stripped down rating.

Automatics have to have the heat and stall ratios sweet spotted to get the normall 33 to 35% power drop an AOD/ 5R55/C5 or FMX/C4/C3 represent. Normaly, dyno figures show a 42 to 63% drop with the stock Ford test 1650 and 2350 stall converters, even if they have a lock-up clutch. Same with lock-up clutch THM's vs non lock-up clutch THM's.

In the article above, wit a stock stall ratio, the engine lost 53% of its net dyno figure, and when a low stall , but higher flash converter was added, the engine lost just 28% through the drive line. When you bolt that C4 up, don't be supprised if your increases become decreases, as automatics on dynos really mess up the conventional logic. In other instance PHR showed in July 2008, a 496 cube engine with 626 flywheel hp heading down to 419 hp, a 49% power drop through an auto is common, and when a tighter converter was hooked up, it gave 448 rwhp, still a loss of 39%. These figures are the norm for automatics of all types and for all engine outputs, from 97 cubic inch Escorts to 514 cubic inch strokers.See http://www.popularhotrodding.com/tech/1001phr_1975_chevy_laguna/viewall.html#ixzz2KgGLE33V

Informed, you can go back to your regular dyno program with enlightened happiness.
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Wow. Some good numbers and in a good street rpm range. I see in your sig you are running the Isky 262... Were you running a bigger cam and a little more compression at one time?
 
64falconsix":lxyuql6t said:
Wow. Some good numbers and in a good street rpm range. I see in your sig you are running the Isky 262... Were you running a bigger cam and a little more compression at one time?
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Yes the other engine had flat top pistons & a larger camshaft. 10.4 compression.
The difference in the numbers on this engine is the difference in annular boosters in the carburetor.
The previous engine is on the engine stand now with a totally different camshaft designed by Jay Allen & ground by Comp cams.
In this engine the Isky is a very mild steet camshaft. I believe a Clay Smith 264 @ 112 L/C would have put out more power, but i chose the Isky for a little more low end.
 
CobraSix":1mtwotc0 said:
All the more reason to upgrade to a T5!
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Yes & no. The T5 would give me 10% more power to the wheels, but my C-4 doesn't miss a shift & is consistant.
If you can't full throttle shift your T5 you might loose the advantage. If you back off the throttle between shifts you gained nothing.
The overdrive in 5th would be a welcome addition.
 
wsa111":1qzdmxgu said:
CobraSix":1qzdmxgu said:
All the more reason to upgrade to a T5!
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Yes & no. The T5 would give me 10% more power to the wheels, but my C-4 doesn't miss a shift & is consistant.
If you can't full throttle shift your T5 you might loose the advantage. If you back off the throttle between shifts you gained nothing.
The overdrive in 5th would be a welcome addition.
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Agreed! :nod:
 
CobraSix":3f1bi7k6 said:
from a drag racing vantage point I understand. I just look at everything through the prism of a daily driver.
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Yes as a daily driver if you don't mind shifting fuel miliage & a little gain in performance would be a plus.
As i said the C-4 is very consistant & consumes less drag than an AOD.
For strip use with a proper stall converter & gearing i will still take the C-4.
I believe with a decent shifter a T5 can be power shifted ok.
I had an 89 5.0 & the T5 was a POS compared to a borg warner T-10.
With my 62 corvette all i had to do was get out of the hole & keep the pedal to the metal.
It shifted like an automatic if you listened to the engine sound on full throttle from 1st to 4th.
Good discussion, both have there advantages.
 
Nice! But as far as the overdrive is concerned... there is always Gear vendors. 8)

This is assuming you are able to squander a couple grand into coffee cans in the garage safely away from the prying eyes of the wife. :D
 
Nice to see those numbers. I can't wait to get our road race car reliable enough to take and get a dyno run done on it. Its pretty similar to your specs, but with a Rochester 2GC 2bbl on it and a 264 Clay Smith cam in it. We had been running a C4 and even with the SROD missing 3rd gear the difference in power is noticeable. My co-drivers claim it now accelerated in 4th (.8 OD) as good as it used to in 3rd in the C4.
 
When i get the 10.4 compresson engine in & with the solid lifter camshaft in i think 160-170 HP at the rear wheels is possible??
The camshaft is a custom grind. Duration is 262I & 280E advertised. Duration @ .050" is 234I & 246E.
Net lift is .568"I & .553"E.
I already have longer valves to allow for the extra lift.
Just hope the small camshaft diameter will be able to handle 130# seat pressure & 330# open??
 
wsa111":2u83ehnh said:
When i get the 10.4 compresson engine in & with the solid lifter camshaft in i think 160-170 HP at the rear wheels is possible??
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Bill...when do you think you will install this engine?
 
Gene Fiore":exvw0w43 said:
wsa111":exvw0w43 said:
When i get the 10.4 compresson engine in & with the solid lifter camshaft in i think 160-170 HP at the rear wheels is possible??
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Bill...when do you think you will install this engine?
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Gene, it may be late summer. It all depends on a nagging knee problem. If a knee replacement is necessary it definetely will be late summer.
I have all the componets ready, short block all assembled, camshaft installed & degreed.Bill
 
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