Dyno measurements .. RWHP and RWTQ

[HealeyPassion]

I have a question....has anyone done dyno runs on a stock AH BJ8 or BJ7 to get real world rear wheel horsepower and torque data (chassis dyno's measure the hp/tq at the rear wheels and produce graphs showing the hp/tq across the tested rpm range)? I have checked with a number of the usual suspects that rebuild 6 cylinder Healey engines and I haven't found much in the way of quantitative data. I think it's fair to say the published hp numbers were based on some data and some marketing requirements (such as "we have to advertise more hp than that!!"....). Granted these are supposed to be hp/tq numbers from the crank, not the rear wheels where it really counts. And, it is HIGHLY suspect that the BJ8 actually makes 19hp more than a BJ7 with only minor cam and carb. tweaks....this is sort of an "in your dreams" number, IMHO.

Anyway, I was going to dyno my BJ7 EFI Healey but with no comparison data I had no way of knowing what would be considered a baseline. So in an effort to do some of my own data gathering and baseline development, I talked a local friend into dynoing his very nice running stock BJ7, advertised at 129 to 132hp (depending on source). This would be the first time we'd had Healey's on the dyno so we didn't have a clue what to expect. Net, net, the BJ7 put down 96.8 hp at 4,750 rpm and 132 tq at 2,750 rpm. Which would say that it's got 111 hp at the crank (rather than 132hp), using the common 15% drive train loss for a solid axle car.

I'm not going to go into all the detail on this post...my real reason for posting is to see if we can collect some real dyno data on big Healeys. Enquiring minds want to know.

Thanks,
Steve

 

[HealeyPassion]

So this has been up for a couple of days and had 40 views.....yet, not one reply. So I guess no one has dyno'd their big Healey....or, is it that none of you really care what power your car is making?? How about the guys that have put on aluminum heads, or headers, or bigger SU's, or anyone of a host of performance parts that were suppose to provide more power...do you ever wonder if you are getting your monies worth??....curious. I guess I'm the odd one in this group.....oh, well it's not the first time.

Cheers,
Steve

 

[GregW]

Hi Steve,
I haven't had the chance to do that since my car is still in pieces. It will be nice to get all I can out of the Mikunis. Well, that and the "other things". :wink:

 

[red57]

Steve,

I didn't respond before because I've been wanting to do it for years now, but there aren't any rolling roads near me. Last year I found out about one about 2 hours away but I have not gotten around to it yet. And my motor is not stock anyway - it's bored, fully balanced, and extensive head work, and a fairly long duration cam with headers.

After running it with 2 HD8s on a log manifold for over 10 years with no problems, last year I put together a tripple HD6 set-up. Went thru heck all season trying to get the needles polished right. I have oxygen sensors and gage and the mixture was nicely on the rich side but in races the chambers got so hot they warped valves and even started to melt a piston once, ended the season with it off-the-charts rich at full throttle but at least it lived thru the last one (I think the extra fuel cooled things just enough). So with 4 motor rebuilds to get thru a 5 race season, I decide the rolling road was the way to go. Aside from tuning help I also want a baseline for myself so I can try a set of tripple HD8s next and compare.

Anyway, haven't done it yet but I am hoping to get to it before the racing starts in April, and when I do I will be happy to share info with you. I really like your idea because I have the same inquiring kind of mind. Please make any database you generate available to us all.

Dave Phillips

 

[HealeyPassion]

Dave, I can see where a chassis dyno (rolling road) would be extremely helpful for you. It is SOOO much better to sit in the car while stationary and read the instruments while your run the car through the gears... make changes....do it again and see the impact. I believe this is true of good running stock engines as well as highly modified engines, as yours is.

Anyway, I do plan to share my dyno data with you guys. I plan on at least 2 sessions with my EFI Healey. My EFI guy, Ric Navarro, has a rolling road minus the measurement equipment... so we have been doing initial ECU tuning on that to smooth transitions, cold start, etc... the problem is, besides not having the measurement instrumentation, his doesn't apply enough braking to adequately load the engine. So, we then need to go to a "real" dyno with all the measurement stuff (he was given the rolling road so while it doesn't have all that's needed it's better than nothing). Last Wednesday was an extremely interesting session....as noted in the inital post. What I left out of that post is that my car delivered 107 hp (11 more than the stock carb. car, or 11%)...keep in mind mine is also stock...and Ric, my EFI friend/guru, believes, based on the information he was collecting on his computer, that there is 10 to 15 more hp in there. Conventional wisdom is that a good running EFI car can deliver in the 20% area over a similar carb. car. Now we go back do some more work at his shop and then go for another "real" dyno session to see if we can find that addition hp.

Having said all that, let me say I didn't start down this path back in 2006 to get more hp/tq ... I did it to improve the all around engine characteristics (cold start, throttle response, mileage, etc.)....the added hp is a side benefit.....okay, also I thought it would be fun to have it injected.

I digress.... I'd love it if some other cars, stock and modified, would post chassis dyno rwhp/rwtq numbers so we can start to get a sense of what these machines are really delivering.

Thanks,
Steve

 

[Michael Oritt]

Steve--

A few months ago I dyno'd my Elva Courier which has a 1500 MGA race engine in pretty advanced state of tune--probably about 12:1 compression and long duration cam, etc. We came up with about 98 HP at 6K rpms at the wheels which is about right.

I'm in the midst of installing new exhaust headers and a Maniflow intake manifold, both of which may give a few more HP. I am trying to get ready for my season opener in late Feb. but I would like dyno it again to see what if anything I have gained in addition to a lower bank balance.

 

[Lin]

Michael,
Where did you do the dyno work?
Lin

 

[BertVanBrande]

Did anybody ever try the iphone (or ipod touch) applications 'pocket dyno' or 'dynolicious', I have no $$$ interest just wondering if this would be usefull.

These apps use the iphone built in accelerometer to time runs and derive RWHP

* 0-60 Acceleration
* 1/4 Mile Elapsed Time
* Lateral G's
* Horsepower
* Friction Circle
* Downloadable Timed Run Graphs
* Downloadable Skidpad Graphs

and more...

https://www.pocketdyno.com/index-1.html
https://www.dynolicious.com/

reviews:

https://gizmodo.com/5030749/iphone-apps-we-like-dynolicious-car-performance-meter
https://www.dailybuzzz.com/cars/new-iphone-dyno-software

These applications are cheap: $2 for pocket Dyno or $13 for Dynolicious.

The reports on accuracy are encouraging, but I must admit I didn't do a full research yet (BN2 is only getting ready for frame paint) Given a sturdy mount and consistent measuring methods it seams like a cheap and easy method to measure difference in tune-ups.

There probably is always somebody in your club or neighbourhood with an iphone (or loan your kid's ipod touch) We can also collect data and publish on a website/forum topic for comparison. Ofcourse everybody would need to use a similar mounting method and calibration.

Test rwhp safely...

Bert

PS: There is software to convert a laptop into a road dyno but it is more involved as it needs a hookup to ignition.

 

[Michael Oritt]

Lin--

There is a place near Budd's Creek Speedway, south of Mechanicsville, MD. At the time I was there the O2 sensor was not working, which would have been nice, but we were able to track, plot and print out HP and Torque.

I'll get the name of the place and send it to you.

 

[HealeyPassion]

Bert, IMHO while I suspect these devices could provide some good data for comparing upgrades on your own car and measuring performance level ... although I'm not keen on the idea of using these on the public highway. I am, however, a bit skeptical about them providing valid comparative data that someone in Baltimore can use to compare their car to a car in Denver. Why? A pro chassis dyno, when properly set up, will factor into consideration things like temperature, humidity, altitude, etc. and provide data adjusted for these factors that can be compared to someone at sea level (for instance, Denver is at 5280 feet so we give up real hp/tq due to less oxygen). I think this is a key value in going to a professional dyno....we, AH community, can have real numbers to compare regardless of altitude, temperature, and humidity.

Cheers,
Steve

 

[GregW]

Aside from tuning help I also want a baseline for myself so I can try a set of tripple HD8s next and compare.

Hi Dave,
You could always try a triple Mikuni conversion. That'll give you tunable accelerator pumps.

 

[red57]

Greg,

Believe me I've been drooling over your set up for quite a while now. Problem is in vintage racing all things have to be 'period correct' and your Mikuni set up would deffinately be noticed by someone.

I race with SOVREN in the norhwest, and we have a choice of 'in the day' regs to follow - either SCCA or FIA. I'm not too familiar with FIA rules but they do allow webbers, trade off is you must have knock off wheels (can't have bolt-on with lug nuts) which I don't want because of unsprung weight. Alternatively according to SCCA we cannot run webbers, must have SUs - oddly enough my tripple HD6 set up is technically not legal but a tripple HD8 set up is legal. I haven't gotten any flack because at least they are SUs and smaller than what is allowed & I am relatively slow because I drive it to the track & back and don't really want a grenade motor. To further confuse... In SOVERN the cut off for 'vintage' class is 1962 (63 to 69 is 'Historic' class) So everything, regardless of the SCCA/FIA rules has to be period correct and had to be available in 1962. That's why when I was running 2 HD8s I used an early mainfold enlarged because the BJ8 came along after '62 and the later mainfold is technically not 'period correct' for the Vintage class.

Now on the other hand, Steve's EFI using SUs as throttle bodies really intigues the 'cheater' in me and I have been wondering.... Nah, never mind - too much work and I'm sure I couldn't hide what it was well enough to get away with it. Nice daydream though. Besides, I know SUs pretty well but am lost with 'hi-tech' stuff like EFI.

Anyway, the Vintage rules are part of why I am embarking on a 'nasty boy' project - I really want to do what I want without regard to who approves for a change.

When you get yours dynoed, we all want to know "the rest of the story" on those Mikunis.

Dave Phillips

 

[HealeyPassion]

Greg, how large are the Mikunis? What cam are you using?...anything else you want to share. This maybe old news to regulars but I'm not up to speed on Greg's secrets.

Steve

 

[GregW]

Hi Steve,
No real secret's, there just spread out over the forum. From what comes to mind, here are the mods.

3 42mm Mikunis. These don’t have any butterflies, so when your WOT, the only obstruction is the needle.
Tri-carb manifolds with a little porting
Iskenderian ground cam 268° duration, not too wild.
High lift 1.55:1 roller rockers.
Block relieved for exhaust valves
Aluminum head
Lightened flywheel
.020 overbore with 9:1 compression pistons
Jacobs electronic ignition
60,000 volt coil
Mallory dual point distributor, points gutted
Pertronix ignitor
Sparkplug gap increased to ½”
OK, I lied about that last thing
Denis Welsh headers, Jet Hot coated
Custom 2” dual exhaust

 

[GregW]

Alternatively according to SCCA we cannot run webbers, must have SUs - oddly enough my tripple HD6 set up is technically not legal but a tripple HD8 set up is legal.

Hi Dave,
I see your point. I both agree and disagree with the rules. Guess that's why I think Smokey's antics were so funny. I loved the story where the tech inspectors took his gas tank out and he still drove the car away.

 

[HealeyPassion]

Greg, I would love to see what your rig would put down in a dyno pull.....sounds like a really sweet package!

Cheers,
Steve

 

[dougie]

Well with all this Dyno talk I thought it was time to chime in. Oh, and it's great to hear from you Dave and I love my spline drive knock-offs by the way......unsprung weight and all.

Here's my story. My '57 100-6 MM currently has a 1960 2912cc mildly tuned for track/street use, it's street legal. Like Dave I have ran two 2" SU HD8's on a log manifold, I believe he has more head work and taller cam, etc. I put the car on the dyno at Lyonings here in Portland after the 2nd SOVREN
race last year and was so disappointed with the numbers, I really didn't want to share. Since I've been mining for more HP and even more torque this off season my old dyno readings will old news.................I hope. I run Sunco 110 standard and pulled RWHP=126@ 4618 RPM and
RWTQ =161@ 3100 RPM. Now I know why most people quote flywheel numbers.

The good news is the twin SU's are gone for this season along with about 100lbs. of unwanted weight
(The Mayer diet). In my research for cams to mate up with the triple 2" SU HD8's on the Ruddspeed performance manifold I'm using for this season I contacted Mark Baker owner of Sport and Specialty who has built a similar motor. Here's part of Mark's email to me.

"Bill's engine was built to try to do what is usually not a good idea. A design that was both good for track events and road worthy. It doesn't have the huge duration camshaft that full race engines have. It has a 290 degree duration with .305 lift. He's using a 1:65 roller rocker ratio which gives him approximately .500 lift at the valve. The cam is advanced to 105 degrees to help with the torque. The block had to be relieved for the exhaust values." Compression 10.03 to 1, the power is linear and consistent and pulls well through the midrange to 6000. Dyno rolling road showed 180 RWHP on pump gas.

Not bad for a streetable Healey. Hey Dave, see ya at the "Defrost Kick-Off"..................If I can get everything back together in time!

Dougie

 

[HealeyPassion]

Dougie, thanks so much for chiming in!! This is the kind of information that is really helpfull in understanding what kind of real world hp/tq our cars are putting down. It seems from your note that you also have the head flowed, hotter cam (specs?), compression?, maybe headers?, etc..... I believe this also further adds to the thought that the advertised hp/tq are quite optimistic. It also speaks to the reality that I don't think most any of us can accurately judge what our cars are putting out... this isn't a knock to Dougie....certainly we thought my stock EFI Healey was going to better than 107 rwhp the first time out.... we still believe it has 120-130 rwhp with tuning but time will tell.

AH Spares has some dyno graphs (https://www.ahspares.co.uk/en/Media/Default.aspx?Play=Movie) on their website that shows a stock BJ8 putting down about 83 rwhp and their stage 2 6 injected Healey putting about 104 rwhp....which they are quite proud of because it's 24% improvement. So, is a good stock BJ8 really an 83 rwhp car.... which is about to say about 100 hp at the crank?

So, are there anymore of you guys out there holding back on your numbers? I believe the more data we get on our LBCs the more realistic we can be on what our cars are putting down.

I'd be extremely interested to see what Dougie gets out of his new engine.

Cheers,
Steve

 

[John Turney]

I've seen some published graphs somewhere (I have copies of them in Excel), but without the background, they're not much use now. I think they were in one of the Healey books.

 

[Monkeywrench]

Keep in mind when calculating flywheel horspower that it's 15% loss of the flywheel horsepower, not of the rear wheels.

Assuming a 20% loss, just multiply your rwhp by 1.25.