I'm waiting for my N4 cams to arrive and thought I'd do a baseline run so as to have a means of comparison - before and after.

My previous dyno run showed my bike at about 78HP, 75ft-lbs. The only changes that have been made are the SE II's changed out for the Python 2-1 and the addition of the TC88A ICM.

Watching the dyno and as I expected, the bike is running too rich. I don't want to try and tune the carb at the moment, I'll wait till the cams are in and then do it. So, the bike is running very rich - about 11:1 at WOT, but the numbers are still good, very good based on the mods to my bike.

Max power = 94.73 HP
Max Torque = 92.04 ft-lbs

I'm thinking with the N4's and properly tuned I might hit 100HP.

Basic motor is stock - changes are Big Sucker, HSR42, Python 2-1 and TC88A ICM.

Cheers,

Brett

Wow, that looks very impressive, i wonder if you could get it to 100 with just tuning.

I doubt that I could pick up another 5-6HP with just tuning, but don't know. I am pretty confident that with the N4's fitted and tuned properly it will get there.

I still wonder if the numbers from this run are accurate - it seems a big difference between now and my previous run. But it is the same dyno and he did several runs and all came up about the same so I guess it's true.

Certainly from SOTP, the bike definitely pulls stronger than with the SE II's and stock ICM, but I wasn't expecting these results.

Cheers,

Brett

I think those are way high. I'm spending $2500 to get there!

I think those are way high. I'm spending $2500 to get there!

I agree, but they are what they are. I was surprised but he did several runs, all of which looked pretty much the same.

It is running very rich and I wondered if maybe that contributed to the good numbers, but usually leaner means more power, richer means less.

Cheers,

Brett

Man thats almost 17hp from just a ignition and a pipe but you already had a good pipe so you could'nt gain more than a few from the screaming eagle's to the python's. Most motors i've seen with that kind of hp all have alot of headwork. I hope thats the hp you really have but something just not adding up.

no head work? stock 40 mm carb? 1200 at stock compression? stock cams still....and running rich.....miracles can happen...but you still always want a second opinion.

WOW thats preety good numbers for a stock bike with with a few upgrades. Hope you hit your 100hp mark with the cames. Im probbley going to put mine on the dyno when I get it back. Mines a stock 883 with a Andrews V4 cam, adjustable pushrods, JIMS Hydrasolid Lifters, and a S&S Super E Carb with a K&N Filter. Am waiting on my Python II's. Also got Taylor wires and Accel Plugs. Hope to be up to the 60hp range or so.

Hmmmmm....sure is a lotta horses for limited mods.

I wonder if they had the HP CORRECTED on the dyno? Do you have the dyno sheet?

I wonder if they had the HP CORRECTED on the dyno? Do you have the dyno sheet?

Precisely... One of my former co-workers was touting 200HP from his '05 Hayabusa, with nothing more than slip-on muffs. One look at his dyno sheet told me that his bike was only putting out around 150HP. When tested, the dynomometer had registered an air pressure of 22.73" Hg, which resulted in an SAE correction factor of 1.35!

Check the information on the bottom of your printout. If it's not on there, talk to the operator, because something is amiss.

BTW... 22.73" Hg would only occur in nature within the eye of a hurricane hundreds of times greater in magnitude than Katrina. Roughly translated, its 770 mbar; Katrina only weighed in around 889 mbar.

no head work? stock 40 mm carb? 1200 at stock compression? stock cams still....and running rich.....miracles can happen...but you still always want a second opinion.

Stock head and compression - yes.
Carb is the Mikuni HSR42

The last dyno I had was without the TC88A and Python 2-1. First I changed pipes to the python 2-1. SOTP this made a reasonable difference in power. The biggest difference I noticed was with the TC88A and using a custom profile, largely developed by Turbota.

Same dyno, same operator. He had my previous runs saved on the machine and brought these up for comparison.

Cheers,

Brett

I wonder if they had the HP CORRECTED on the dyno? Do you have the dyno sheet?

I've got the sheet in the office, forgot to bring it home with me yesterday. I'll check it when I get in and let you know the SAE adjustment.

Cheers,

Brett

You must have a hard time keeping that front tire on the ground.

You must have a hard time keeping that front tire on the ground.

It has never been a problem, but then I never take off agressively. Never felt the need on any of my bikes to lift the front wheel.

The only bike I've had where that was a problem was a Yamaha RD400 which I bought off Yamaha NZ when they finished using it for production bike racing. That thing was the fastest bike I have ever had - up to about 160kmph, then it ran out of puff. I had to work hard to keep the front down on that bike. Fond memories of that bike.....but ended up planting it into the side of a car which did a u-turn in front of me. Luckily I wasn't even doing the speed limit at the time but the front of the bike was totalled. I bought if off the insurance company, put a used set of fork/wheel, etc on it and sold it for a nice profit.

Cheers,

Brett

ok, the info at the bottom of the datasheet from yesterdays run shows barometric pressure at 24.65 in-Hg and SAE adjustment at 1.27.

Since this is lower than the lowest air pressure ever recorded, I guess the results are very usable. I'll have to check this next time and see how the operator is adjusting for these variables.

Ok, so the results are crap. Unless there is some way of adjusting these results I can't even use it as a baseline for future mods.

Cheers,

Brett

Figure out the actual barometric pressure for the day, if you can, and post the figures. I'll give you the proper correction factor.

Alternatively, just go off of an uncorrected figure, by dividing your HP and torque measurements by 1.27.

Bolt -

I had one of those RD400E's, too. What a little rocket. At about 6K RPM in 1st gear, if you weren't careful with the throttle, it would flip right over. Watched a couple of buddies do that. Second gear wasn't much better...Blip it at about 7k and the front end would come right up. Made speed shifting a whole lotta fun!

Up here in CO, at 5400' elevation or so, we typically get CF's right around 1.20 or so.

A really hot summer day, it may get up around 1.27. A really cool winter day, it may be down around 1.15.

The charts I've seen from coastal areas are generally right around 1.00. Sometimes a little lower, say .97 or .98, sometimes a little higher, say 1.02 or 1.03, depending on the day. I can't imagine a 1.27 in Singapore.

Older dyno's (model 150 & before) required the environmental measurements to be made manually and then enterred into the software. Automatic weather stations were introduced in the 90's in the Dynoware EX package (assuming this is a Dynojet) on the model 168/188/200/250. Many guys updated their 100's and 150's. Lots of room for operator error in those older setups. Also one of many many ways to cheat with a dyno. Not that I think this was intentional, I can't imagine why he would. I'm sure it was just a mistake.

Sometimes you see people who advertise dyno sheets and alternate between SAE, STD, and uncorrected, whichever shows the highest number on that particular day. Caveat emptor.

so your probably right around 75 or so, right where i would expect it to be

Figure out the actual barometric pressure for the day, if you can, and post the figures. I'll give you the proper correction factor.

Alternatively, just go off of an uncorrected figure, by dividing your HP and torque measurements by 1.27.

Looking at the adjustments, they seem all wrong - on the dyno sheet it shows 31.84 degrees C, 24.65 in-Hg, 39% humidity

Actual weather was 30 degrees C, 29.83 in-Hg, humidity 94%

I'd be interested in seeing the adjusted results.

Cheers,

Brett

Bolt -

I had one of those RD400E's, too. What a little rocket. At about 6K RPM in 1st gear, if you weren't careful with the throttle, it would flip right over. Watched a couple of buddies do that. Second gear wasn't much better...Blip it at about 7k and the front end would come right up. Made speed shifting a whole lotta fun!

I cannot deny that it was a FUN bike. I was very sorry to smash it up, not to mention the physical pain involved.

I'd probably still have it if it hadn't been so badly damaged. I fixed it up, but didn't feel the same riding it after that so sold it.

At the time, it could beat just about ANYTHING away from the lights - a fantastic around town flier.

Cheers,

Brett

so your probably right around 75 or so, right where i would expect it to be

I expect it to be higher than 75. It was 76 before fitting the 2-1 and TC88A. I expected somewhere around early to mid 80's. I not overly bothered one way or the other, the more important thing for me is the AFR. This latest run certainly shows that changing the pipes to the python and changing the ICM has completely screwed up the AFR. I knew this from the fuel consumption, but is VERY clear from the latest dyno run. Now running rich right across the board.

I'm not going to try and fix this till I have fitted the N4's.

Cheers,

Brett