FWIW My Pro Gas vs Alcohol dyno ##

M

Mr angery

Member
Have not seen a lot of data posted so I thought I would share and maybe get some feedback into what you ended up as far as ### OR %

This is our first PG motor so I am sure we have more to learn and we did not do much tunning on it.

Steve Baker has posted some on this and has given input on setup and I Thank him for sharing that info.

One thing for sure is With .5 HP being 5% on 10 HP it dont take much to make or not make a couple of percent.

HP 5 run average on each motor. Track time/will be raced at 20 lbs less then the Alcohol Motor.



RPM PG Alcohol Differance.
4000 10.56 11.66 9.4 %
5000 12.46 13.95 10.7%
6000 12.9 13.63 5.4 %
6500 12.3 13.06 5.8 %
7000 11.1 12.43 10.7 %
7200 10.8 12.15 11.1 %
 
My initial thought would be they should be closer on top end than what they are. Do you have the data for closer to 8000 rpm, which is what we turn on roadcourse?
 
Where is th peak hp at on each? 5000 seems very low for an alky engine? I thought it was closer to 6000
 
Mr Angery,

As Gary stated, we see the Pro Gas HP numbers / graph, getting closer as the RPM Levels increase. I think I posted this info awhile ago and can do again if needed. I just need to pull up some dyno pulls. The Pro Gas engine with its 20 degree larger profile camshaft than the BP alky engine, make good power as the RPM levels are spooled up.

Steve
 
Gary
I don’t have any dyno data above the 7200rpm
In the past with the alcohol motors we run the wheel until 7400 rpm and record to 7200 rpm. Run dirt oval so we don’t run as many rpm. (Not to say I should not be recording higher)

PK HP on alcohol at 5100/5200 rpm
PK hp on the pro gas 5800/5900 rpm

Not sure why but my PK HP RPM # erzzz have always seemed low.

I have seen some say the inertia wheel and depending on how you have the program set/what ratio you run etc will do that.
(Again area I may need to spend more time and investigate as my PK HP my not be correct, shoot it all could be wrong for all I know LOL)
Its Performance treads pro version and its set to record every 100 rpm.


Steve
I remember you saying around 6% less on Pro Gas but don’t recall any graphs or at what rpm that accrued. Feel free to share any graph info you care to share.

I am with you two on the thinking that it should have more up top as the cam is bigger and I should move a bit more air as I have ½ the fuel. But I am no pro that’s for sure. I guess with a drag car switched over to alchol you pick up HP with all thing s being equale so my thought may be squed on the air. Need that air flow meter.
 
Mr angery,

I found this data that was posted a few months back and is still a good representation of comparison data. Remember however that comparison of dyno data to other dyno machines is questionable. We believe that our dyno data is about 3% low for the correct HP based on SAE J607 correction factor (60°F day with 0% humidity and a barometric pressure of 29.92 in-Hg). This is due to the frictional losses that are generated in our belt drive coupling system.

Animal Pro Gas HP
10.25 @ 5000
11.25 @ 6000
10.50 @ 7000
9.0 @ 8000

Animal Alky HP
11.50 @ 5000
12.00 @ 6000
10.75 @ 7000
9.25 @ 8000


Steve
 
Last edited:
MR A pro gas Alcohol
RPM HP
5000 12.46 13.95 10.7%
6000 12.9 13.63 5.4%
6500 12.3 13.06 5.8%
7000 11.1 12.43 10.7%

Mr Baker pro gas Alcohol
RPM HP HP
5000 10.25 11.5 10.9%
6000 11.25 12 6.3%
7000 10.5 10.75 2.3%
8000 9 9.25 2.7%



Good point Steve and I Know my HP is higher then actual HP. Its one of them things where I got my wheel and software. Needed to put an inertia value in so I did matching it to a motor I had dynoed locally . Weeks later figure out that data was higher then actual HP. But at that point have much data collected and don’t want to correct it all. Hope you understand.


Looking at it in % at RPM I am matching up pretty good with your data until 6500
That’s the story right there.
I need to figure out the 6500 above issue i am having.
Thanks again and if anybody has ## to post or input dont be shy !!
 
Thanks for this great post and taking the time to pass on this valuable information. Years ago I had a friend that wanted to dyno his motor at my facility. This was a V-8 alky motor. I had no experience with alky at the time so I was very surprised at how the motor did not make power above 8000 RPM. The motors we were running never fell below 8000. I am now running opens and a UAS kart and we run extreme RPM in both motors. 10,000 plus. Your info has me thinking that maybe I am over looking the upper RPM limitations of running alky. Thanks again!
 
Does any one have the numbers (% diff) for a IKF or WKA Animal on Gas?
 
If the alky engines peak power is 6k and has really fallen off by 8k why does everyone turn them so tight. Wouldn't make sense to gear it to around 7200ish? Or am I missing something...
 
Jimbo said:
Does any one have the numbers (% diff) for a IKF or WKA Animal on Gas?
Click to expand...

Jim, That would be basically your BP Animal alky with a gas carb on it. The IKF internal engine specs for alky and gas are the same except for carb and fuel. If my memory is correct the Alky gains over gas is in the 10 to 15 % range.

Steve
ge.

Steve
 
In the data above i'm seeing a 10% difference at some rpms.
My thought is weather a BP Gas Animal compete with a PRO Gas with some other kind of adjustment like a weight break?
Maybe it's not a factor but it might boost the numbers if needed.
 
The dyno does create an unrealistic load (at higher RPM's) that is not experienced on the racetrack as it relates to straight-line speed. Thinking that the reason methanol & pump gas have less separation of HP at higher numbers, has much to do with how fast it burns.
 
I always thought it was because of the huge increase in fuel took up port volume and therefore the high RPM was effected. My open animals make peak power at about 9200 with alky.. I do know that in drag racing the alky cars lower there RPM. I increase my port size for alcohol. I do not have any real data to back up my assumptions so.... I am guessing a bit here I suppose.
 
Hay all thanks for the help and feedback thus far. I did not work on the PG motor this weekend as i took off and went down to watch the Ponies run at the derby and just relax as been working a ton . Some topics of gas vs alky port size/ rpm /burn time etc etc could get real intersting and i am always looking to learn.

Right now i am wondering about my PK HP ## abeing in the 5100/5300 range when looking back at hundereds of runs on my alky motors



PK HP on alcohol at 5100/5200 rpm
PK hp on the pro gas 5800/5900 rpm

any input to these PK HP RPM ## I listed as being low ??
The software is spitting out a HP and TQ number every 100 rpm. (not to say its right as it does some pre/post averaging to come up with the ## it displays / Inertia with Trends software )

If ya care to share

Please list what your PK HP generaly is at on a ALKY motor and how many rpm between measurments you record
 
The main reason for the pro gas engine power curve being closer on top end is directly related to the cam profile vs the alky engine. Similar to the world formula it does not make much bottom end but makes a lot of top in comparison.

I would say the peak power for your pro gas isn't out of line at all but the alky is likely more than 500 rpm lower than most will share.
 
I have to chime in here.... Its so nice to hear some of the top guys on this site have an conversation about something that have a gray area (not all dynos will show exactly the same numbers) without getting in a pi$$ing match! I do my best to learn things here on Bob's, and get really annoyed when arguments start over things like dyno results. Thank you for posting your work & results.
Well done gentleman, hats off to you!
VERY respectively yours,
Ken in Wyo
 
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