ATC 250r Drag Engine set up

[bannedbrraap]

I currently run 1/4 asphault drags with my trike...right now my motor works pretty good for a "stock" cylinder motor. bike runs consistent 13.60at around 91-92 mph but its time for some big power...im thinking right now that it makes around 50hp at the wheels but i really dont know. the cylinder is ported with huge exh and transfer ports and big compression, i think maybe a little too much (240 psi). im trying to decide what size cylinder and crank stroke i should use to make the most power that will still work after the 1/8th mile...not many people run past the 1/8 but i run the full 1/4. i was leaning towards the esr 420 cyl with a 77mm stroke. trx 11 porting obviously. and info would be great thanks

[dcreel]

http://www.cpindinc.com/pub/part_list?manufacturer=2

[RideRed250R]

if trailprotrailpro going for the end all, get a puma.

[bannedbrraap]

i have heard nothing but good things about the puma cylinders...but what size is gonna be the best?

[RideRed250R]

431 is the best imho, you will pay the same price to do a 350-399 puma with a stock stroke as you would to build a 431 and those damn things are running 80 plus on gas. and damn near 95 on alky

[bannedbrraap]

what carb and ignition should i be looking at?...im not planning on running alky, i use vp c12, its pretty consistent fuel. i like it....also i use the ftz out of frame drag pipe

[RideRed250R]

big OLE electron on gas your probably going to need between a 42-45 i have heard several are running strong on 50mm's but i cant confirm that... and a cr250 ignition...

[bannedbrraap]

does the puma come as a kit?

[250rmanfmf]

yes, it does come as a kit, go to there dealer page and find a dealer, also there is a kit on ebay for $2,200. I just started to build my 431 puma motor, plan on spending $3,500 min. for setup. I have heard great things about the puma. A Puma Cylinder is basically a KX500 Cylinder.

Tyler

[NOS_350X]

A puma is based off of the new big banshee cylinders. A well built puma or Saber, eather way is a good choise. The sabers are puttin donw better times.

Head over to planetsand.com, that is the drag racer hang out, the guys wiht money and true drag builds are going to be the ones giving you info there.

[Saleenster]

A Puma Cylinder is basically a KX500 Cylinder. Tyler

No its not.

Puma is a Cougar based cylinder.

Why would you not run alky if your racing.....get the most out of your motor. Its just plain silly if you are not. If you dont have it cut already, that would be another thing I would do right off the bat....override tranny.

[bannedbrraap]

at some point i might run alky but i still have 175 litres of c12 in my drum...need to burn that first. i havent done the override because i run the 1/4 mile...i was under the assumption that the override would be good for short distance, like 300 ft or the 1/8th mile (660). All my trans parts are cryogenically treated. i have broken second and third gear with the power my stock cylinder makes. after i got them treated it has been fine.

[Saleenster]

at some point i might run alky but i still have 175 litres of c12 in my drum...need to burn that first. i havent done the override because i run the 1/4 mile...i was under the assumption that the override would be good for short distance, like 300 ft or the 1/8th mile (660). All my trans parts are cryogenically treated. i have broken second and third gear with the power my stock cylinder makes. after i got them treated it has been fine.

Running an override changes nothing in your gearing, you can still clutch into 5th and 6th, just will get you going quicker thru gears 1-4. What gearing are you running to achieve 1320' ?

I'm running 100+ rwhp and I run stock OEM Honda gears and clutch....just FYI

[bannedbrraap]

i run 15/34 with 21" jr dragster tires. my rpm at the end is around the 8600 mark what cylinder are you using to get 100 rwhp?

[bannedbrraap]

sorry..the tires are 19"...i mixed that up...i did have 21" but they didnt works as well as the 19"

[250rmanfmf]

[QUOTE=Saleenster;980586]No its not.

Puma is a Cougar based cylinder.


Its very similar to a KX500 Cylinder, set the puma next to a kx500 cylinder they look similar. Thats all.

[NOS_350X]

What are you braking on 2 and 3rd gear? they shodunt be taking any stress really, it should all be put on first.

Yes an override will help, Take all that time that it takes to shift, It will help in any kind of racing, I love my 1-4manual 5&6

Just because they might looks somewhat simular from the outside start checking everything inside, They are NOTHING alike, Check the timing, night and day difference. If it was like a kx500 trust me it would not be a good drag setup. Also since Saleen is one of the first guys to build a puma i think he knows a bit more about them then any of us on here.

[bannedbrraap]

i have broken the teeth on the gears. I dont leave very hard in fist gear, even with the wheelie bars its hard to keep it straight out of the hole....no tire spin, it hooks really hard but if you leave hard all 3 tires come off the ground, it comes back on the wheelie bars hard. Also i never use the clutch to shift, so maybe thats why the gears take a beating...i dunno

[bannedbrraap]

here is a link to run last fall

http://www.youtube.com/watch?v=uQ_WarfJMnw

[RoscoW]

Ahh The Bend. I try and get there a couple times a year.

[bannedbrraap]

yeah grand bend is nice, but i usually run at cayuga

[bannedbrraap]

Who does the best drag porting for these cylinders?

[riverrat]

Does a cr250 ignition bolt right into an 85r?

[bannedbrraap]

you need an adapter plate ESR sells them

[riverrat]

thanks, which flywheel should you use?

[bannedbrraap]

you use the 2001 cr flywheel and electrical.

[riverrat]

Oh, it has to be that year? I am having trouble with my electrical system, and was thinking of replacing it all.

[bannedbrraap]

well...it doesnt HAVE to be that year, but it is the best one to use. Digital cdi box that has the best timing curve for the 250r. you wont have any power for lights tho
unless you get an aftermarket stator that has 12v output

[bannedbrraap]

Ok so i finally spent some money on this build....408 puma, crankworks crank with YZ490 rod, kurtz 2-4 override ESR cr250 iginition Shearer OOF pipe lectron 44. Should have all this in the bike within a few weeks.

[bannedbrraap]

ohh...forgot the slingshot lockup with hinson basket

[jadleybray]

If you start in first, why didn't you get a 1-4 override? You are gonna find that the trike chassis will be your limiting factor on asphalt. With the extreme amount of hookup that asphalt provides, you will need to detune the bike for launch then come on really hard. I've been fighting the trailprotrailprotrailprotrailpro out of my trike and thats on dirt/sand surface.

[bannedbrraap]

i dont leave very hard in first gear...the trike is all over the place if i leave hard.

[Saleenster]

i dont leave very hard in first gear...the trike is all over the place if i leave hard.

If your ever gonna take it serious, you'll have to learn to launch in 1st, and then you'll find the 3 wheeled chassis like Jadleybrey mentioned with be your limiting factor no matter how great of a rider you or or become. Take it from me, I did just that. Built a drag trike, then we developed a motor that was faster then chassis would allow, so I had to change the chassis....

you'll like your new Puma, but they come alive when you put them on alky and at least a 50mm carb. Are you planning on running a pump even though your on gas?

[bannedbrraap]

I wasnt planning on running a pump just yet. Do you think i need to? The cylinder is not ported, i want to run it on fuel first untill i get used to the power it makes. Then i will send the cylinder to Mccoy for porting and get a custom alky dome cut. i will run a 50mm lectron and pump. I bought this engine the way it is. And its a fresh build, so ill run it that way. If i cant get the chassis part of it to work right, i do have an 86 trx frame. I think i need to run different tires out back, some guys on planet asphault say the reason its all over the place when i leave is becasue im running slicks, they say to use American racer tires.

[Saleenster]

I wasnt planning on running a pump just yet. Do you think i need to? The cylinder is not ported, i want to run it on fuel first untill i get used to the power it makes. Then i will send the cylinder to Mccoy for porting and get a custom alky dome cut. i will run a 50mm lectron and pump. I bought this engine the way it is. And its a fresh build, so ill run it that way. If i cant get the chassis part of it to work right, i do have an 86 trx frame. I think i need to run different tires out back, some guys on planet asphault say the reason its all over the place when i leave is becasue im running slicks, they say to use American racer tires.

No you wont need to run a pump if your on gas. However, if the cylinder is already off, I would tap it for a feed line now before you install it. You will get the chassis to be satisfactory, but you'll fight it more then you will probably desire. TRX chassis is no question a better set up right off the get go, but you'll want it to be long in the rear and wheelie bar as long as the chassis. Slicks are what I would run also. Your new motor will power thru every gear, so that will be where you will also need to find what works best. I would start at 16/36 then move to a 34 if you are running out of gear before you cross. The only thing is, make sure you tune the motor to pull thru 6th gear which will likely mean, your gonna be rich throughout your powerband. Otherwise with no pump, you will tax your fuel system and run a high possiblity of burning up the motor.

[bannedbrraap]

i run 15/34 with my stock cylinder engine, turns about 8500 at the end. Where can i get a 16?

[Saleenster]

STU, McCoy will have them, and I beleive Packard might have them in stock. Your Puma will still make power close to 10k if its ported, and will produce a wicked over-rev unlike any Honda cylinder to date. Your override will get you into 5th approx 2-4 bike lenths shorter, so you'll want more gear when you clutch 5th, just be aware of what I mentioned about tuning your motor to take load thru the top of 6th gear, it will be extremely important for you as to not burn up your piston.

[bannedbrraap]

i have a EGT gauge with a quick response probe, ill keep the temps around the 1100 mark and do a plug chop at the end of the run. i can set the gauge to flash at me if my temps get too hot, so ill start low and tune from there

[jadleybray]

The egt is only gonna help once you establish a tune with the plug chop, then find the correlating temp. 1100 is in the ballpark, but every motor will vary. Finding the sweet spot for that distance will make or break your times

[bannedbrraap]

yeah my stock cylinder setup likes 1180. burns down at around 1230. My probe is about 6 or 7 inches from the piston

[bannedbrraap]

Just an update on this thing, running a pump and 50mm lectron with billet bell, 15/34 gearing and 23" tall hoosier super sprint tires, 14" longer swing arm. Ran 12.80 in the quater mile 2 days ago....there is still more in it, but thats a pretty good run on a non ported puma with low compression

[riverrat]

Thats pretty awesome!

[bannedbrraap]

Was out last weekend for the first time since August, needed to get a few more runs in before winter and before i send the cylinder out for porting. First run was 12.9 @ 94mph
Second run was 12.6 @ 99mph third run made me do a little dance when i looked at the time slip.........12.21 @ 106 mph!....

[Xpress]

Woohoo triple digits!! That's screaming fast.

[RIDE-RED 250r]

I made a little mess in my pants reading this thread!! :drool:

Congrats on breaking into triple digits bro! That's awesome!

[250rRoostmaster]

106mph is friggen screamin!!! That's pretty killer

[ezmoney1979]

I am very impressed! That is smokin- Good job!:beer

[bannedbrraap]

Thanks guys...im gonna try and get this thing in the 11 second et's next year and hopefully close to the 115 mph mark

[HONDA_ATC_FREAK]

now that's hauling the mail lol