How much horsepower does the 400ex have at the crank and at the real wheels?And whats the difference?Thanks
Jeff

28HP......not sure if thats rear wheel or what

Dont know the horsepower rating but I do know the difference. Horsepower at the crank is pure engine power. It is horsepower measured at the crankshaft. Horsepower at the rear wheels is a true measure of rideable horsepower. It is measured of course at the rear wheels on a chassis dyno which is just 1 or two big rollers in the ground. the diffence is that the horsepower at the wheels is horsepower from the crank after it has been lessened by different mechanisms such as the transmission, sprockets, and chain. These mechanisms especially the transmission are not 100% efficient. This is why the horsepower at the wheels is less. Hope this clears it up.

2000 400EX, FMF Powercore IV, Dynojet kit, 14 tooth front sprocket.

THE 400EX HAS 25 HORSE POWER NOT SURE AT REAR WHEELS THOUGH.HOND SHOULD PRODUCE A QUAD WITH THE XR650 MOTOR AND CALL IT THE 650EX.
ERIC

THE 400EX HAS 25 HORSE POWER NOT SURE AT REAR WHEELS THOUGH.HONDA SHOULD PRODUCE A QUAD WITH THE XR650 MOTOR AND CALL IT THE 650EX.
ERIC

Thanks guys i understand now.Anybody know the rear wheel horsepower?
Jeff

Ownership papers say 32hp, pretty sure that's at the crank, because most dyno charts I've seen show 25-27hp peak at the rear wheels.

MY 2001 400EX MAKES 27.3 HP AT THE REARHEEL WITH A YOSH FULLSYSTEM A K&N FILTER JETTED AND A XR250R REVBOX ........I INTEND ON PUTTING IN 440kit WITH CAM AND SOME HEADWORK...............PUSHIN FOR 40hp PLUS........

40 H.P. ? ppfffh,,, good luck!

I paid the 50 bucks to have mine dynoed. I have 28.2 hp at the rear wheels. This is of course, with the chain, clutch and throttle adjusted properly. People don't understand how important this is. After I do all of my mods, the shop said they'd only charge me 10 bucks now. That's why i did it now so i can compare the differnce. I'm telling you guys, for a thousand bucks in mods to the 400ex in the motor, the Raptor doesn't look so good anymore. With the right mods, you can be at 42 hp for a thousand bucks. Ya gotta shop around.

thanks for the info all dynos are diff. but that narrows it down a little.Let us know if you do any future mods and dyno it

jvc400ex is right.I don't know what my 440 big bore would measure in h.p.But in Marienville Pa. yesterday at the Tour de Forest my 440 big bore ate a raptor 3x on the pavement.The drag race was about 300'and the blue raptor didn't have anything for this honda.Believe it.1700 people registered and I don't know how many were at our parking area but the cameras were out.That's not a story that's a fact!!!! 2000 400EX-440 big bore,w.b. cam,DJ155 main,ported-polished,w.b. e-series pipe,k/n filter,17 tooth front sprockett,20"shredders,Douglas wheels,Renthal bars,Maier grips/guards,SKIN graphics...The raptor was stock,but that extra 220cc wasn't enough....FACT.........Sammy

If you have a 2001 you already have the XR250 Rev Box in it. I have a 2001 and i already checked, its the same.

The guy had to be an extremely inexperienced rider. I think we all know that.

brad400ex
I work at a dealership and i know for a fact that the 2001 400ex box is NOT THE SAME ...it has been proven on the dyno ....bigboy400ex

quad father, yamaha engines arent known for their high power for displacement (exept for the yz426 and the banshee, which has a crappy powerband) if you put a cam, bump up the compression, and bore it out a little you have the raptor beat. the ex is still 30 lbs lighter, 2 inches wider (i think), shorter, and has better suspention but that is pretty close.

Well my dad owns a Honda Dealership.
If there NOT THE SAME then why are they the EXACT SAME part number???

if they have the same number which i will check that on tuesday ...they do not revup the same on the dyno ....i can prove that without a DOUBT .......

I am planning on taking my brothers 400EX with SParks X-4, CT icm, Sparks/Uni filter, and jet kit. To a dyno as soon as a I get my 400EX motor back, which will be a Sparks 440 National.

I am doing it more for novelty's sake. I am curious to see what they do. Basically the mods on my brother's bike are what I rode for over a year.

Has anyone taken a highly modified 400EX to a dyno, and if so what were your numbers? I think it would be interesting since too many people want to say what you cant do to a 400EX. So lets find out what you really can do!

Adam Smith

99 400EX

It would take alot of money for a 400ex to touch a Raptor

How about a 400ex with 11:1 compression and a hot can with a FMF pip from front to back

This is a pretty old thread. You may want to start a new thread in the Honda section to get an answer. -Moderator