51hp 473cc kit!

[Hondamaster5505]

I just came across this.

These are some pretty impressive numbers for a 473:eek2:

http://images.google.com/imgres?imgurl=http://www.geocities.com/Baja/Ravine/4093/fdo.gif&imgrefurl=http://www.geocities.com/gtthunder.geo/news.html&h=468&w=639&sz=13&hl=en&start=12&tbnid=pAMhvjRK5mVWkM:&tbnh=100&tbnw=137&prev=/images%3Fq%3Dstock%2B400ex%2Bshock%26gbv%3D2%26svn um%3D10%26hl%3Den

[priebo15]

damn. end of story

[CarGuy7a]

that's awesome. that piston looks freakin killer.... those headers are pretty trick lookin too.

[sc400ex_rider]

this exhaust shootout is sweet to. very interesting reading. there seems to be alot of politics and smoke and mirrors when it comes to aftermarket exhausts. i guess they dont want people to know they just spent $500 to pick up .5 HP and make alot of noise to piss off your neighbors.
http://images.google.com/imgres?imgurl=http://www.geocities.com/Baja/Ravine/4093/fdo.gif&imgrefurl=http://www.geocities.com/gtthunder.geo/news.html&h=468&w=639&sz=13&hl=en&start=12&tbnid=pAMhvjRK5mVWkM:&tbnh=100&tbnw=137&prev=/ images%3Fq%3Dstock%2B400ex%2Bshock%26gbv%3D2%26svn<br />um%3D10%26hl%3Den

[Franky G]

My old 460 was putting out 53HP so that 51HP sound decent for a 470...

[blue_ex_rider]

What cam was you running in your bike Franky

[maxfior]

WOW! That is an impressive number, especially since it's at the wheels. I'm sure at the crank the engine was making 56 or more. If I had another 400EX to play with / not afraid to blow up, I'd try this kit in a minute (that is, if I had the cash lying around too :) ) Pretty damn cool!

Max

[randallp1]

who sells the kit? what kind of parts required?

[Hondamaster5505]

Originally posted by randallp1
who sells the kit? what kind of parts required?

Idk, you have to call them. I think its GT Thunder

[RATPACK Z400]

I had a friend that had a 502 kit on he,s ex and was only putting out 45 hps on dyno so those numbers to me sound way to high for a 400ex!A stock 450r puts out 35hps and the 400ex around 25hps just sounds unreal! Not to call anybody a lier.

[XXXRACER165]

Your friends 502 must not be built very well then.

Originally posted by XXXRACER165
Your friends 502 must not be built very well then.

yeah your right because think of a 440 you will see numbers in the 40's if its built right. a 502 must have had like a 5:1 compression or something wrong only making 45HP

[RATPACK Z400]

So what your saying is that a 40ccs will net you 20hps on an 400ex motor not real alot a racing Co.s will over estimate hp #s to get you to buy there kits go and look at ctracing,trinity,nacs, etc I bet you wont find any kit for 400ex thats 50hps.Please dont think that Im trying to call anybody a liar I just know theres no such kit. Astock 400ex is only 25 hp thats alot to gain in 40ccs or 70ccs 40ish hps with 440 and 50ish with 470 kit there arent any other quads out there that can put up #s like that with 40ccs or 70ccs.

[blue_ex_rider]

It is bot all about how big the motor is as in cc's. You go to also consider how much fuel it is getting how much comppression is in the motor how well the motor can breath and etc. Patrack cc's isnt the only thing that can givwe you hp. So it all depends on what that 440 has in it or that 470 has in it besides just 470cc's. there is alot of hp you can get out of these ex's just depends on how much you want to put in it.

[blue_ex_rider]

i would bet that the 470 kit that is pushing over 50 just dont have a hi comp pistion and stroker crank. I bet they have alot more things done to the head bigger cam good pipe and etc. It cost you abour a 100 dollars a hp so its all about how much you want to put in the bikes.

Theres a guy on here with a 440 not a huge amount of work really and he is pushing 42HP all motor and 62HP with his nitrous. 40HP is where a good 440 will be.

[416exfreak]

Originally posted by RATPACK Z400
So what your saying is that a 40ccs will net you 20hps on an 400ex motor not real alot a racing Co.s will over estimate hp #s to get you to buy there kits go and look at ctracing,trinity,nacs, etc I bet you wont find any kit for 400ex thats 50hps.Please dont think that Im trying to call anybody a liar I just know theres no such kit. Astock 400ex is only 25 hp thats alot to gain in 40ccs or 70ccs 40ish hps with 440 and 50ish with 470 kit there arent any other quads out there that can put up #s like that with 40ccs or 70ccs.

It isnt just the 40 extra cc's. You also factor in the cam, compression, timing advances or retardations, port work, exhaust sytem/filter used...etc.

There are many factors that contribute to the HP readings of an engine. It doesnt rely solely on the displacement.;)

[blue_ex_rider]

A 440 bulit well is be in the low 4o's. and a stroker built well should be in the 50's espcially any stroker that is bigger than a 460 like the 502 you metioned. So if a stock 400 is around 27hp getting to 40 would prolly cost you around 1300 and getting to 50 is going to be around 2300 or more. But that dont take much when you consider getting the head done right is about 1200 bucks . there is hp in a 400 is juts might cost a little to get it out of it.

[416exfreak]

Originally posted by blue_ex_rider
A 440 bulit well is be in the low 4o's. and a stroker built well should be in the 50's espcially any stroker that is bigger than a 460 like the 502 you metioned. So if a stock 400 is around 27hp getting to 40 would prolly cost you around 1300 and getting to 50 is going to be around 2300 or more. But that dont take much when you consider getting the head done right is about 1200 bucks . there is hp in a 400 is juts might cost a little to get it out of it.

It only costs if you dont know how to do it yourself.;) :cool:

[blue_ex_rider]

unless you can make pistions pipes cams valves carbs and have a flow bench to port a head right it will cost you that much wheter you do it yourself or not.

[gcart2]

im at 35 hp and my motor has not been bored over. However the motor has been built by ex pro honda rider.

[RATPACK Z400]

I seen those ads before there BS they want you to buy there kit ! Thats cool if you believe all that but I,ve seen grafhs like that for the 450s the Zs,etc its all made up BS,they have a 470 kit for the 450r honda that puts out 58 hps and one for the Z that put out 55hps do you really think that the ex motor can come close to such performance as the new 4-stroke motors they make now!But thats cool not trying to argue anymore you,ll believe what you believe!

[coryatver]

that graph is really old from gt thunders old web site when the 400ex just came out. That guy doesn't need to lie to get work. If any dyno numbers are close to being correct it is his he is very picky on how the dyno is ran such as doing runs the same day, tires, same dyno all that has an effect.

[XXXRACER165]

Originally posted by blue_ex_rider
A 440 bulit well is be in the low 4o's.


Mine NOW has 46hp

[416exfreak]

Originally posted by blue_ex_rider
unless you can make pistions pipes cams valves carbs and have a flow bench to port a head right it will cost you that much wheter you do it yourself or not.

I was talking about doing the port work yourself.

You dont HAVE to have a flow bench. If you understand how the air travels and how it flows through the runners, then you just go to work with an air grinder and porting tools.

I did my own portwork andI picked up 6 HP from it.:ermm: