lets make the 400ex a little quicker

[cals400ex]

well, its time to mod the 400ex again. i realize there are 101 different ways to do it but i really don't know where to begin.
here is what i am looking for:
i want a horsepower bike, low end power isn't a big factor. i do want reliability. i would prefer to run off 93 octane, but i realize that may not be possible. i am pretty much open for suggestions after this being said.

i am thinking about stroking it but i am not sure. i don't want to bore really huge. my goals are to be as quick if not a little quicker than the new 450r in a drag race. i am not worried about on a track/trails. i have no desire to have a 100% race bike because i do cruise around a bit too. also, i don't see a point of dumping in a ton of cash when i can get the same power, reliability, and performance with a cheaper more economical route.

right now i am running a 10.8:1 406, x-6, and stage 2 cam. i am not sure, it may only take a fcr and a port job to run with a newer bike. any ideas would be great. thanks

[K_Fulk]

I would start with the fcr and a port job. You will get some decent gains and it would be a lot easier then stroking first.
If you still want more then get the stroker.

[Doibugu2]

Originally posted by K_Fulk
I would start with the fcr and a port job and the fcr.


Putting 2 FCR's should make some huge power gains.:D

[K_Fulk]

Yeah the more the marrier. :D

[Aceman]

Stroking tends to be slower revving I've heard and produces more torque. The way you make it sound you like lots of high rpm topend power. I think you would be better suited for a bigger bore high compression motor. Big bore kits are faster revving and add more hp, unless your piston is so large it's a big heavy slug then it won't rev out as fast.

[SnellCRP]

The cheapest things you could do to your EX to make it faster would be get a lightened flywheel, add a timing advance key, go with no base gasket and a thin head gasket to get your squish clearance to about .035-.040 and when you get your carb spend some serious time tuning it and if you have dyno access you can find alot of HP that you would never be able to find by just "seat of the pants" tuning. My .02.

[UglyMotha™]

somewhat cheap


http://www.imagestation.com/picture/sraid107/p01f423d48c2b42d9fc91cace5db2711b/f967bfc2.jpg

[400exdad]

How much weight did you take off of it? Do you have any before and after weight figures?


Originally posted by UglyMotha™
somewhat cheap


http://www.imagestation.com/picture/sraid107/p01f423d48c2b42d9fc91cace5db2711b/f967bfc2.jpg

[UglyMotha™]

Originally posted by 400exdad
How much weight did you take off of it? Do you have any before and after weight figures?



a butt load, i don't have any exact number i sent it to rocky ridge and told them to do something with it and they did what they call the ultra light mod but if you look at the center strip that's left that was the original thickness of the fly wheel all the way across and the step down section in the back was also turned down quite abit

[cals400ex]

what kind of difference did the fly wheel make?

[UglyMotha™]

i dunno, i'm still holding :confused:


but with all that weight gone it should rev a whole lot quicker

[RAPTORAZ]

Here's some dyno numbers to show you what you're up against. These numbers are from Kenz Cycle Tech in Arizona.

450R stock made 37.1 RWHP.
With HRC kit it made 41 RWHP.
My 416 (mods in sig) made 33.5 RWHP on same dyno
My buddies 465 stroker on alky made 48 RWHP on same dyno.

So for you to make the same HP as a stock 450R, you're gonna need at least a ported head and carb.

And for you to make the same HP as an HRC kitted 450R, you're gonna need a 440 with a carb, 12.5 compression(say goodbye to pump gas), an awesome port job, and a very healthy cam.

[member]

ummm....426 13:1 comp port and polish, hot cam stage 2 .. might need titanium valve springs but i have no clue, maybe some oversized vavles, 39 fcr? stronger connecting rod, lightened fly wheel.... i dunno sounds like a good set up to me ... might be some other stuff but that sounds good to me.. maybe a gt thunder rev box for some more top end

[nacs400ex]

I for one wouldnt get a drop in cam. Get something agressive, sure you will have to get hardened rockers and stiffer valve springs, but I am sure the difference would be worth it especially with a 426 or 440.

[RED121572]

...just trade your 400 in for a 450R.:D

[cheetah]

Originally posted by RED121572
...just trade your 400 in for a 450R.:D

probably be cheaper in the end.:devil:

[2003EXRIDER]

seeing those dyno numbers just makes want a 450 even worse!!!:( :(

[RAPTORAZ]

Originally posted by 2003EXRIDER
seeing those dyno numbers just makes want a 450 even worse!!!:( :(

If the front end is as light on the 450R as they say, I'd rather build an EX. Constantly having to shift your weight from front to back coming off corners gets tiring quick. That's why my Raptor now has an extra +4.5 inches added to the swingarm.

If you like those dyno numbers, I'll email you my 727 Raptor's dyno sheet. 63 RWHP on gas with the stock carbs. :devil:

[exatak199]

Nitrous would be a good Idea!


http://www.boondockers.com/images/Img120.jpg

just a little over $200 you get good power.:eek2:

http://www.boondockers.com ;)

[markeg192]

Originally posted by UglyMotha™
somewhat cheap


http://www.imagestation.com/picture/sraid107/p01f423d48c2b42d9fc91cace5db2711b/f967bfc2.jpg

I have one of those myself.

[cals400ex]

Originally posted by markeg192
I have one of those myself.

you like that flywheel lightened? did you get a gain from it?



i perfer not to run nitrous. i would rather spend the cash and run a turbo. i don't want to mess with refilling the bottle. great gains for the price though.

[UglyMotha™]

what's this thread turning into the sportcompactriders.com :huh

[Cripple]

www.paatving.com/Articles/turbo400ex/turbo400ex.asp# , these guys and KMS racing are the only ones out there that i know of with a turbo kit