426ex dyno

[scottdom]

If anyone is interested in a 426ex dyno. Pulled 36hp and 27 tq

[honda400ex2003]

nice chart for sure! you have 2 hp on my 416. what kind of mods are on it?
steve

[scottdom]

open air box with k&n and outwear, stage 2, port and polish, 450 carb, 13.1 piston. I know every dyno is slightly different and our dyno operator told us that his runs about 25% lower than most so if that true I'd be closer to 42-46ish. Not sure if I believe that but whatever. What I like about it is the power doesn't drop off much at high end. All I know is that I kick alot of 450r (slightly mod) butts.

[CJM]

VERY nice!

I wonder how much my 416 has then I realize hp is only a relative thing, its all about the riding :D

Congrats you made that much tho, its impressive.

[honda400ex2003]

that is probably a couple of hp low but hard to say how much.

I ran 34 hp with a 10:1 416 with stage 2, t-4 slip on, headers ground, k&n, and an open box.

id def be happy with an extra 2 hp that is quite a bit when talking about these engines.
steve

[drew416ex]

Originally posted by honda400ex2003
that is probably a couple of hp low but hard to say how much.

I ran 34 hp with a 10:1 416 with stage 2, t-4 slip on, headers ground, k&n, and an open box.

id def be happy with an extra 2 hp that is quite a bit when talking about these engines.
steve

Yeah thats pretty close. Maybe a couple low. I pulled 46hp with my 440 stroker on a dynojet :D

[PLF]

Originally posted by scottdom
open air box with k&n and outwear, stage 2, port and polish, 450 carb, 13.1 piston. I know every dyno is slightly different and our dyno operator told us that his runs about 25% lower than most so if that true I'd be closer to 42-46ish. Not sure if I believe that but whatever. What I like about it is the power doesn't drop off much at high end. All I know is that I kick alot of 450r (slightly mod) butts.


Whats your pipe ??

[honda400ex2003]

i cant wait to get my 440 done this summer. i would like to see 40 but that is probably wishful thinking without doing quite a bit more work to it. The only other thing i plan to do is get a header for it to go with the current setup that i am running with the 416 listed above.

steve

[CJM]

40 would be sweet, at this point Im happy with where I am and if I get the chance Im gonna nab a 450R only b/c with water cooling I could just change the piston to 13:1 or better and not worry about the heat it generates.

[honda400ex2003]

im thinking around 37-38 will be about all im going to get. hopefully a bit more torque though with that big monster and 11:1. steve

[CJM]

Probably be a torque monster with that setup. I went with the 416 since I have 2 more bore jobs than can be done should something go wrong. Sooner or later Ill either wear it out or go 450r tho, not getting rid of the EX tho..never..

[Thumpin440ex]

Nice numbers for sure man. I wish i could round up a dyno around my place. I would love to see what kinda a numbers it would throw down on the rollers...


John

[scottdom]

pipe is curtis spark. My buddy who does port and polish learned of a new technique call HVP. Alot of the pro use it. I don't totally understand the theory but basically you cut down the intake ports which creates more vacuum and velocity. So, we did an experiment on mine. We ported and polished another head with non HVP and we re-dynoed....we actually lost 2+ hp across the board with out the HVP. Needless to say, we put the old head with HVP back on! Need those ponies when we head to glamis next month.

[400exshop]

I got 39hp and 62tq on my 440 and that was on motor.
But on nos it was 60hp and 89tq I think here is the chart.
http://i825.photobucket.com/albums/zz179/ericcrip/dsc01774.jpg

[RATPACK Z400]

Man with torque like that you would rip chain off the sproket ! those torque #s seem off. ive seen 50 torque but never 89.Not saying you BSing but thats just plain insane #s

[witech]

Thats quite an absurd dyno chart. Why is it printed out in speed? It should be done in rpm . The torque numbers for sure are impossible. The horsepower curve does look like a nitrous curve but torque would be around 40 to 45 pounds with a 60hp engine. Nowhere near 86. I wonder what was messed up at the the dyno shop?

[400exshop]

the tq is why we can run 8.30 on motor and 7.80s on nos it come out of the hole so hard it hard to hole on if you not good at riding . i have had a lot of people get on it and say it no a 400 motor.

[Thumpin440ex]

Not going to piss here, but no way in hell the tq is that much over the hp.. Def a spike in the dyno of some sort...

John

[RATPACK Z400]

yeah with torque like that you would rip motor from frame! HA HA

[witech]

Im going to show this to our local dyno operator next time I go . Maybe he can make sense of how it can show such bogus readings. Its like someone changed the scale values or something. They both go to 100.

[honda400ex2003]

http://aroundthesphere.files.wordpress.com/2010/04/popcorn.jpg

Ive got the popcorn. IBTL

steve

[Thumpin440ex]

Originally posted by honda400ex2003
http://aroundthesphere.files.wordpress.com/2010/04/popcorn.jpg

Ive got the popcorn. IBTL

steve

Lol why do ya think its going to get locked.. Just for the record, I am not bashing or **** talking. But something with that graph is not right...

John

[honda400ex2003]

just in case. lol I like healthy discussion though as this is. steve

[witech]

After a bit of discusion I think the answer is the rpm setting on the dyno was set to the wrong firing per revolution which is what the computer uses to determine torque. If set to a 2 stroke which fires every revolution it will calculate double the actual torque. It will also show the engine spinning double the rpm on the run screen. So your real torque should be exaclty half of what the chart lists but horsepower would be correct as that an inertia calculation not determined by engine rpm.
Dont know why I didnt think of that yesterday as we ran into this problem several times at the dyno .
Anyway thats pretty good for a 400ex.

[Scro]

Originally posted by witech
After a bit of discusion I think the answer is the rpm setting on the dyno was set to the wrong firing per revolution which is what the computer uses to determine torque. If set to a 2 stroke which fires every revolution it will calculate double the actual torque. It will also show the engine spinning double the rpm on the run screen. So your real torque should be exaclty half of what the chart lists but horsepower would be correct as that an inertia calculation not determined by engine rpm.
Dont know why I didnt think of that yesterday as we ran into this problem several times at the dyno .
Anyway thats pretty good for a 400ex.

That makes sense. I don't remember ever seeing torque numbers higher than the HP numbers on quad.

[witech]

Ive run nitrous on quads and its easy to see a nitrous dyno run compared to a regular run. The torque curve is just crazy high right off idle and usually flatlines or drops as rpm increases. No doubt his 400ex is fast he just got confused by a lazy/incompetent dyno operator when hooking it up. In fact if you go to a shop and they dont bother hooking up a tach lead I would just leave. And always take a memory card or blank disc to get the runfiles you payed for. Getting one printed out chart is pretty much useless for improving on engine setup and tuning.