Must Have Parts For Stock Class Drag Racing

[cheater13]

I'm typing this off my iPod so sorry for the errors. Well I'm dragging my 400ex this august and I'm goin to want to do a few things to it. Right now I have a k@n powerlid, a outerwears prefilter, a FMF Titanium 4 exhaust with a powerbomb header. I'm going the top end and replace the chain and sprockets later on. I was thinking of port and polishing it but dad debated because the engine is already mostly aluminum, which is smooth unlike the old cast iron engines back in the day, and he said it wouldn't be worth the money to do that. Is that true? Also, since he said that, I was then thinking to get either a hot cam stage 1 or 2 but I'm not too sure on which one yet. What do you guys think? It's stock class so I can't bore it any.

[CJM]

Hotcam stage 1 works best in a stock engine, it will give you gains all around but tends to lower the topend slightly.

Look into the rules, but you might be able to run a sparks 6 degree timing key to give you back the topend you lose with the cam.

As for port and polish, it helps on these engines cause the head although machined very nice is still rather rough inside.

Otherwise your gonna want to keep that sucker as low to the ground as possible. Look at the most popular 400ex thread and read about how to put on some stock 450R shocks. These have adjustable preload so you can lower or raise the suspension.

[Scro]

Without going with a bigger bore, the most power gain you will see is a ported head, a high compression piston, and a more aggressive cam.

[cheater13]

Oh ok thanks. Yeah I think stage 2 was more toward top end but I wasn't sure. And if I got a more compression piston, what would I have to get besides the piston? Wouldn't u have to bore it if I get a higher compression piston? And what's a price range for getting the head just polished?

[HondaPohl]

You can do it yourself!

[JOHNDOE83]

Most important it to take off as much weight as possible and get paddle tires for the dirt and drag tires for pavement.

Also change your gearing for what type of drag racing your doing.

[Scro]

Originally posted by cheater13
Oh ok thanks. Yeah I think stage 2 was more toward top end but I wasn't sure. And if I got a more compression piston, what would I have to get besides the piston? Wouldn't u have to bore it if I get a higher compression piston? And what's a price range for getting the head just polished?

You don't have to bore when going with higher compression. With a higher compression piston, the area inside cylinder when the piston is at top dead center will be smaller. This is the because the top of the piston will be raised slightly, and will have deeper valve pockets. The air and fuel are being compressed into smaller area, which makes more power.

[cheater13]

Ah ok. So far I'll probably get a stage 1 cam and a high compression wiesco piston. In the port and polishing part, could I just polish the head and see gains without porting anything?

[3400ben]

P&P from Moto-Xperts Will be about $350. I don't think you will see any gain just by polishing, you need to remove material. This is well worth the money.

[Dobber]

id try to contact Janssen motorsports to get the p&p done..it seems like they've got the drag porting down pretty soon.

http://janssenmotorsports.com/

edit:also, what kind of draging are you going to be doing?

[cheater13]

I'm beginning with the local 300 foot drag if that helps.

[Dobber]

lowering it is a must. a good set of tires would also help a lot. i run maxxis 4-snows and they seem to hook pretty good. how much are you looking to spend on all of this?

[cheater13]

Yeah I have holeshots on it now and lowering it means I'll have to put a pair of good shocks which cost a good amount of money. And in trying to spend as least as possible. Probably under 700 but that includes a top end rebuild.

[400exshop]

Originally posted by cheater13
I'm typing this off my iPod so sorry for the errors. Well I'm dragging my 400ex this august and I'm goin to want to do a few things to it. Right now I have a k@n powerlid, a outerwears prefilter, a FMF Titanium 4 exhaust with a powerbomb header. I'm going the top end and replace the chain and sprockets later on. I was thinking of port and polishing it but dad debated because the engine is already mostly aluminum, which is smooth unlike the old cast iron engines back in the day, and he said it wouldn't be worth the money to do that. Is that true? Also, since he said that, I was then thinking to get either a hot cam stage 1 or 2 but I'm not too sure on which one yet. What do you guys think? It's stock class so I can't bore it any.
what parts are already mostly aluminum on the motor ? a good p&p will help you out with a 12.5.1 to 13.1 cp piston its lighter then the wis. get more info befor you jump in to it so you dont spend any money that you dont have to.

[cheater13]

I'm assuming most of the parts are aluminum in the 400ex. And that's what I'm kind of trying to do by asking you guys. I mostly shop on rockymountain but they don't have any other pistons besides wiesco.

[Dobber]

Originally posted by cheater13
Yeah I have holeshots on it now and lowering it means I'll have to put a pair of good shocks which cost a good amount of money. And in trying to spend as least as possible. Probably under 700 but that includes a top end rebuild.

you dont have to get shocks to lower it..you could get by with a lowering kit. some people hate on them..but thats what i use to lower my 400 and i've never had any problems. you can pick one up off of ebay i think.

holeshots aren't really the best for dirt drags..but if your not going to get really serious into this they'll probably get you by.

i started draging last summer just for fun..but i've gotten addicted..and my 400 becomes less and less a trail rider all the time.

before you go to the race..you might want to find somewhere that you would be able to practice your starts too as they can be tricky sometimes. it might not sound like it that important..but i found that a gripper seat helped my starts alot! i used to always slide to the back causing the front end to some up, but with the gripped i stay planted until i want to move to the back. just throwing it out there.

[cheater13]

Ok thanks. Yea I have alot if fields and everything here to practice in, im just in need of the parts for my 400ex to help it alot because there is always 450r's there and they haul.

[Dobber]

dont that have a class for just 400s there?

[cheater13]

No.. Thats the unfair part. It's just a local fair and I want to give drag racin a try. Even though there's a stock class people come in with bored 450's and banshees and enter them in the stock class because people dont know if it's bored without taking the head off. That's why I need the most bang got the buck without boring mine because I still want it to be somewhat of a trail machine.

[Dobber]

you can still have it as a trail machine and be bored out..i ride my drag 440 on the trails still every once in a while..and i got a buddy with a yfz thats like a 526 or something like that and he still trail rides

but if your wanting best bang for your buck id do hi comp piston, stage one hot cam, gearing will also be a big part. i would also run it without the air box lid and prefilter for the drags. and of couse you'll have to re jet. you could also get a 3* timing key from a guy off of here named wheelie i believe. they work nice in high comp engines or go with a sparks key if you go lower comp.

[cheater13]

Ok thanks. Yeah i kinda don't want to bore it yet but does it do anything if I did take the prefilter off and the k@n lid and ran it? And what about the port and polish. On rockountain atv I'm pretty sure they only sell weisco so I'll probably get one of them pistons. I would need a piston that would run with 93 octane because that is the highest they sell around here.

[400exshop]

you dont have to get a kit to lower it just strap the front and rear down. with some straps. it takes 5 min. and go racing. have you been to a asphault drag strip ? look at some of the bikes some are strap down.

[Dobber]

Originally posted by 400exshop
you dont have to get a kit to lower it just strap the front and rear down. with some straps. it takes 5 min. and go racing. have you been to a asphault drag strip ? look at some of the bikes some are strap down.

you could do that if they allow it. we used to do that..but don't allow it anymore so i went with the kit.

taking the prefilter and lid off is going to allow for air to be brought into the engine easier.

if you want to stick with 93 octane than the highest i would go is 11:1 comp.

and you would probably see some gains with a port and polish..and if you researched it enough you could probably even do it yourself.

[cheater13]

Ok thanks but how and what would I strap down?

[Dobber]

i believe you just wrap it around a higher spot on the frame, and the a arms and tighten it up

[cheater13]

Ok thanks but with them rubber tie down straps?

[Scro]

Originally posted by cheater13
Ok thanks but with them rubber tie down straps?

No. If you are going to do it, use a strap that's not going to give.

[cheater13]

Alright thanks for the help. I have a good idea of what I'm going to do to it but I need help on a big problem, I have a 3/4 inch hole in my canister and I'm looking for a stainless steel welder. Is that the only option I have because I really don't want to get another exhaust?

Also, I was thinking about a 450r carb to put on the 400ex. Would that have good gains?

[cheater13]

any help on that?

[Red_250EX_Rider]

Originally posted by cheater13
Alright thanks for the help. I have a good idea of what I'm going to do to it but I need help on a big problem, I have a 3/4 inch hole in my canister and I'm looking for a stainless steel welder. Is that the only option I have because I really don't want to get another exhaust?

Also, I was thinking about a 450r carb to put on the 400ex. Would that have good gains?

I'd just buy a new factory one would be the cheaper route

[cheater13]

Ehh I don't know if it will be the cheapest because if I ever got another exhaust it would be Sparks. I could just weld a patch or something over the hole though.

[JOHNDOE83]

For drag racing take the muffler completley off and jet for it with only the header pipe.

take the battery out and jumpstart it before the race.

take the airbox off.

and get a 450 carb.

paddle tires!

find out if you can use struts instead of shocks for your class!

[cheater13]

Thanks but I never heard jetting with only the header on and jumpstarten it. I'm going to get a 450r carb but do I need any extra things to hook it up?
And would paddle tires work on a dirt track? I thought they were for sand.

[Red_250EX_Rider]

Originally posted by cheater13
Thanks but I never heard jetting with only the header on and jumpstarten it. I'm going to get a 450r carb but do I need any extra things to hook it up?
And would paddle tires work on a dirt track? I thought they were for sand.

I think he means racing paddles like prowedge tires 2.

[cheater13]

Oh ok I understand now. I just called FMF and they recommended to get a R&Dbowl for the Honda. What would that be?

[Red_250EX_Rider]

Originally posted by cheater13
Oh ok I understand now. I just called FMF and they recommended to get a R&Dbowl for the Honda. What would that be?

I cant help you on that part seems like its a a diff bowl to go on the 450r carb to cause less bog and allow more fuel.

[cheater13]

Thanks though but yeah he was talking about the carb and that and said it would cost around a few hundred bucks and I dont think it would be worth it a whole lot. He said it would help it kinda keep up with the fuel injected ones.

[Red_250EX_Rider]

Originally posted by cheater13
Thanks though but yeah he was talking about the carb and that and said it would cost around a few hundred bucks and I dont think it would be worth it a whole lot. He said it would help it kinda keep up with the fuel injected ones

Yea i seen one for 250$ I wouldn't pay that for it ether but thats just me.

[cheater13]

Yea it's probably not worth it.

And for the tires, does rockymountain sell any real good ones for the dirt. I have holeshots right now and there descent but running low on tread.

[Red_250EX_Rider]

Originally posted by cheater13
Yea it's probably not worth it.

And for the tires, does rockymountain sell any real good ones for the dirt. I have holeshots right now and there descent but running low on tread.

I see some sand but on tires if you think the holeshots are hooking good get you another set. mine be able to find some cheap drag tires on here through the classifieds.

Edit these might be alright

http://www.rockymountainatvmc.com/productDetail.do?navType=type&navTitle=Tires+and+Wheels&webTypeId=138&webCatId=8&prodFamilyId=17494&allVehParts=true

[cheater13]

They look pretty nice bit they look like there made more toward flattrack. Yeah I had both Razrs and Holeshots and liked both. But you think them tires you sent me a link of would do any better than razors or holeshots?

[Red_250EX_Rider]

Originally posted by cheater13
They look pretty nice bit they look like there made more toward flattrack. Yeah I had both Razrs and Holeshots and liked both. But you think them tires you sent me a link of would do any better than razors or holeshots?

Thats what i was thinking there more toward the flat track but if the Holeshots were sticking good why risk it. But since they are meant to grip.

[cheater13]

Yea I migh stick to holeshots or give them ones a try. I'm not quite sure what model of holeshots I have but what's a good model of tire for drags?

[Red_250EX_Rider]

Originally posted by cheater13
Yea I migh stick to holeshots or give them ones a try. I'm not quite sure what model of holeshots I have but what's a good model of tire for drags?

Not real sure i know a friend of mine must of the time ran those racing paddles on his YFZ450 and those were the one i first told you about.

[cheater13]

Oh ok so you think them Duro tires would be a good tire for drags?

[Red_250EX_Rider]

Originally posted by cheater13
Oh ok so you think them Duro tires would be a good tire for drags?

Id doubt it its according to how deep the thread gaps are and how far apart they are. Those look like flat tdirt track racing tires.

[cheater13]

Alright. What would be a nice tire for 300ft drags then?

[Red_250EX_Rider]

Originally posted by cheater13
Alright. What would be a nice tire for 300ft drags then?


I would take a trip to the local drag strip and see if they was a dominate tire or ask someone who drags on here

[cheater13]

Ok thanks. Yeah I know a guy that been drag racing for a while. Here is my list of what all i plan on getting done:

Port and polish
Stage 1 hot cam
Wiseco 11:1 stock piston
450r carb
Everything jetted and synced together
1 tooth up in the rear
Gold series chain
Rear drag tires
And I'm getting a top end rebuild


This sound good? Keep in mind I'm not boring it because im entering in stock class.

[Red_250EX_Rider]

[QUOTE]Originally posted by cheater13
Ok thanks. Yeah I know a guy that been drag racing for a while. Here is my list of what all i plan on getting done:

Port and polish
Stage 1 hot cam
Wiseco 11:1 stock piston
450r carb
Everything jetted and synced together
1 tooth up in the rear
Gold series chain
Rear drag tires
And I'm getting a top end rebuild


This sound good? Keep in mind I'm not boring it because im entering in stock class. [/QUOTE


Would lighting the flywheel help? And would it be aloud

[cheater13]

What's good about that? And yeah it probably would.

[Red_250EX_Rider]

Originally posted by cheater13
What's good about that? And yeah it probably would.

With less weight on the flywill you'll have quicker acceleration but lose some on the topend

[cheater13]

Oh ok I think I'm just gunna do what I listed unless there's anything else can do because I still want to ride In the woods and play around with it in the fields.
What about a sparks key?

[Red_250EX_Rider]

Originally posted by cheater13
Oh ok I think I'm just gunna do what I listed unless there's anything else can do because I still want to ride In the woods and play around with it in the fields.
What about a sparks key?



Idk you could try it

[cheater13]

Would I have to run higher octane fuel in it if I get the sparks key?

[Red_250EX_Rider]

Not for sure maybe cjm or one of the higher poster would know

[JOHNDOE83]

I meant paddle tires like these, These and maxxis 4snows are the best dirt or sand tire for drag racing.


http://i953.photobucket.com/albums/ae15/johndoe83_2010/newdragex003.jpg

[Dobber]

i run the snows..and they hook pretty good. but if your looking for a tire that hooks good and you can still use to ride dunlop makes a tire that works great. i think its even a stock 400ex tire.

http://www.rockymountainatvmc.com/productDetail.do?navType=type&webTypeId=138&navTitle=Tires+and+Wheels&webCatId=8&prodFamilyId=15819

thats pretty much what everyone around here runs if there not using snows or paddles.

[cheater13]

Ok sweet. Out of them two tires, which one would grab alot better on wettish dirt?

[Dobber]

are you asking between the two that have been posted, or the snows and the dunlops?

[cheater13]

The ones that been posted. But for the snows, I wouldnt be able to just ride around with them right?

[hocman123]

Originally posted by cheater13
Would I have to run higher octane fuel in it if I get the sparks key?

if u have a stock piston u could have a 6 degree timing key i not need to use race fuel all u would need is 92 to 93 pump gas.

if u go up in compresion then u would have to take it out or but a 3 degree key in to stay on pump gas

[cheater13]

I'm going to go with a stock wesico 11:1 high compression piston so should I get the 3 degree? And I would be running iton 93 octane.

[hocman123]

well u could get it and try some people say there bike pings a little with 11:1 with the 3 but others say they are fine. also if u staying with the stock bore then u should be ok but it is hard to say most people that have trouble with the 3 have 416 or 440 engines with that compresion

[Dobber]

Originally posted by cheater13
The ones that been posted. But for the snows, I wouldnt be able to just ride around with them right?

you could just ride around in the snow with them lol.

but between the ones posted i would go with the dunlops. its what i use when im not using the snow and they seem to work great..and the other ones seem like they are ment more for flat track or asphalt drags

[cheater13]

Ok thanks haha. So them dunlops that you posted are good for wet dirt drags? And is there a website to buy the ones that Johndoe posted because they look pretty nice

[Dobber]

yea..they work pretty good. you can buy the ones that john posted off of rocky mountain too. but there a little more expensive..and your not really going to be able to just ride around with them..unless you ride dunes.

[cheater13]

What tire setup are you running? And I already have some holeshots to ride around with but I'll have to replace them soon. Whichever ones hook better in wet dirt/clay I want them.

[Dobber]

my tire set up all differs from race to race. it all depends on track conditions. theres times when i'll start with the snows and then switch to the dunlops and switch right back to the snows.

when you say its a wet track..do you just mean like the water it down, or do you mean that its going to be muddy?

[cheater13]

Oh yeah I know what you mean. And no they just water it down. It's like a clay somewhat.

[Chukkinsod]

Have you tried a set of Pro Wedge 2's ? They are stiffer than the 4 snows with the same design tread. Work great for hardpack and they will allow you to get out of the hole quicker due to the fact they expand.

[cheater13]

No I never did try them. Where could get a pair because rockymountain don't have any prowedge? And it's nit very hard packed but it's not dusty either. It's just like a somewhat wet dirt.

[Dobber]

the original pro wedges are actually the best..but they dont make them any more.

if you want to go with a snow or wedge type tire any kind should do just fine since it doesnt seem like your getting into this very seriously.

[cheater13]

Yeah but what is a good kind of wedged tire that grabs pretty good besides dunlops tire.

[Dobber]

you mean a tire that you could use for draging and riding?

[cheater13]

If I could get one to both drag and ride which one? And what's a good strict dirt dragging tire?

[Dobber]

i would go with the dunlops. in my opinion there probably your best bet for a tire to drag and ride with.

if you go with just a drag tire the snows or pro wedges would be the best.

[cheater13]

Ok cool thanks. Does it matter what kind of dunlops they are though?

[Dobber]

the ones that i posted are the ones your going to want to get.

[cheater13]

Yeah but they look more of a rounded tire, not wide. Would these do any better?

http://www.rockymountainatvmc.com/productDetail.do?navType=type&navTitle=Tires+and+Wheels&webTypeId=138&webCatId=8&prodFamilyId=15818&allVehParts=true

[Dobber]

no..i've tried those..and i couldn't get them to hook at all. and that was on a stock 400ex with just a pipe.

your best bet is the ones that i posted. they might not look like anything special..but there one of the best hooking tires for dirt drags.

[cheater13]

Ok sweet. Do you use them dunlops? And just wanderen if holeshots are pretty good?



Edit: i just found these ones and they have the
Same tread pattern. Wouldnt they be better because there wider?

http://www.rockymountainatvmc.com/productDetail.do?navType=type&navTitle=Tires+and+Wheels&webTypeId=138&webCatId=8&prodFamilyId=15822&allVehParts=true

[Dobber]

yea i used the dunlops i posted when im not using the snows. holeshots are are good riding tires, but there terrible drag tires.

the ones you posted aren't any wider than the ones i posted.

[cheater13]

Oh ok thanks man. Would them dunlops fit on the stock rim? And when do you use your snow tires?

And my holeshots are good for drag racing in the grass and dust

[Dobber]

the dunlops will fit a stock rim. and i use my snows all the time except when it is really muddy.

holeshots hook up good as a trail tires, but if you want a good drag tire i wouldn't even look at them.

[cheater13]

Ok cool I will look at getting a pair of dunlops then. Thanks!