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CRF230 Supermoto dyno results!

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Hello,

 

Did a dyno run few weeks ago and I thought I would share here. 

CRF230M 09

parts and work on head from xr100.com

250cc big bore

Stage 3 cam

valve seat job

high flow job

port matched

TM33-8012 pumper carb, xt225 carb boot/head bored port matched to 30mm

full FMF pipe powercore 4 and powerbomb header

K&N pod filter for street

11.5:1 CR

slotted cam sprocket

 

I don't know much about how dynos work, so don't ask me about if it's corrected and all those other terms. All I know is it pulls hard for a crf230

Peak hp: 26.87

Peak torque: 17.64 ft.lb

93 unleaded pump gas

dynojet dyno at harley davidson

 

Chart attached

CRF230M-'09.png

Edited by Q47
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I forgot to add I did a dyno pull with cv30 stock carb 130 main jet 2 shims under the needle and it was 2 hp less. I recommend TM33 but you have to modify the throttle cable bracket and cut a piece of the gas tank that is in the way. The choke is reachable but with great difficulty.

 

CR too high for forced induction? Thinking about a nitrous oxide system, hmmm

Edited by Q47

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decent graph. Notice dip right before peak. You may try a 3-4" connector hose from filter to carb. Tends to clean up high rpm miss even though these only wind 8500  or so before falling off. 

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decent graph. Notice dip right before peak. You may try a 3-4" connector hose from filter to carb. Tends to clean up high rpm miss even though these only wind 8500  or so before falling off. 

I have the k&n directly attached to the carb, that might be the cause for the dip? I will try the extension but I only have my butt as a dyno for the the time being.

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decent graph. Notice dip right before peak. You may try a 3-4" connector hose from filter to carb. Tends to clean up high rpm miss even though these only wind 8500  or so before falling off. 

I think it might be clutch slip. See the attached image for onset of slip to end of slip. Black thin line might be what the torque should be.

Tried to change clutches today but the knock-off honda spanner tool off ebay broke and the teeth were stuck to the stupid nut.

CRF230M-'09.png

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Well, Butt Dyno it is then. I run into this issue on the 125-200's I build. People shove the "greenie weenie" on end of carb. I tell them to try extension and 90% are very happy with results. Being the 230 is a cousin of XR200 I think same result will occur. Typically cleans up everywhere and much easier to jet in.

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The flat on graph is common on 2 valve singles.  Never a true arc. My race 125 literally had 3000 rpm flat within .5 ft lbs

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The flat on graph is common on 2 valve singles.  Never a true arc. My race 125 literally had 3000 rpm flat within .5 ft lbs

interesting, I thought the flat was because the clutch couldn't take a torque load higher than the flat. I will try the extension and will report back.

Thanks

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Seen people turbo charge wr250x with good results, that bike has higher CR than mine and they did fine after stress testing with no intercooler. I got a RHB31 clone for cheap. Finished routing the exhaust to the turbo and the downpipe. Currently it sits behind the shock where the air box sits. Longer exhaust pipe from the head to the turbo should help with smoothing exhaust pulses. It's a draw through setup with a CV carb. The CV carb has the the butterfly completly open and lets the slide do the work. The throttle butterfly sits on the the intake port for instant throttle response. 

Oil leaks from draw through set-ups seem to happen when the butterfly closes on the turbo inlet causing negative pressure so the oil escapes to the compressor. Having no resistance before the turbo helps with oil leaks. Also I will have the oil sucked through the turbo instead of pushed through it. This will reduce the likely hood of oil leaking to the compressor housing. 

I am also going to run the oil to separate reservoir so I can monitor it's levels and refill easily. 

Should be really interesting to see this done. I will post all the build in detail if it works. If it doesn't then I will not talk about it again.

So many turbo builds posts that failed in the end. For me it's a happy ending or no build post.

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Well, Butt Dyno it is then. I run into this issue on the 125-200's I build. People shove the "greenie weenie" on end of carb. I tell them to try extension and 90% are very happy with results. Being the 230 is a cousin of XR200 I think same result will occur. Typically cleans up everywhere and much easier to jet in.

Man, I can't thank you enough. I did the extension and took it on a 'butt dyno' run. The thing is running better and defiantly noticeable.

IMG_20151122_001713.jpg

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Your welcome, It is always the little things that matter. It is like the drag racing I used to do, once your get baseline it was all the fine tuning. I have a old 380HP 1969 Hurst/Olds. after playing with little tiny changes It would run into the 11's through the mufflers on sticky street legal rubber. 380HP "GROSS" old rating. Yet my dad's (77 years old) 2015 Mustang GT is rated at 435 "NET" HP and weighs 80 lbs less will only run high 12's. I am sure you could play with little stuff and easily get it into 11's 

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Yeah as it is a "Oldsmobile" not some Chevy or Hemi it does fairly well. That is even through a Q-Jet carb.

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Yeah as it is a "Oldsmobile" not some Chevy or Hemi it does fairly well. That is even through a Q-Jet carb.

 

I happen to love the Rochester QuadraJet.  Likely the best compromise of street performance out there.  I still have a huge toolbox full of HEI and Q-Jet parts.  Jets, rods weights...  You name it.

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For guys wondering why I switched back to cv carb. I got some advice from Frank Nye and I took his word on it

 

he said

"ok well we tried a TM32mmon our L with a250 kit 3 cam  EO pipe it ran great...but mileage was down ...reinstalled the stk carb....could not tell the difference on how it ran , it may have been a little better with the flatslide ...mileage shot back up to 90+   from 60/70 MPG , 130 main 38 pilot  holes in airbox lid washer under needle"

 

I followed his advice and it's running the same as before but with an improvement in gas millage. I think what increased the hp on the dyno the second time is not the TM33 carb, it's the enlarged intake port. That's why you shouldn't change 2 variables at once. I am using a 132.5 main 38 pilot 2 1/2 mixture screw, 1 copper washer under the needle. 

 

Listening to advice from Terry and Frank has helped me a lot. Thanks!

Edited by Q47
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Listening to advice from Terry and Frank has helped me a lot. Thanks!

 

+100%!  These two guys possess a wealth of knowledge and we are very fortunate they take the time to help us out.

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For guys wondering why I switched back to cv carb

 

I happen to love the Rochester QuadraJet. 

 

CV carbs are great if set up well. had many on my MG's and Triumph's...and old Honda CL450 for that matter..

 

never was much on the V8 tuner seen, but I've never like working on a QuadraJet or even a Holley....all yuck!

I always preferred a good Alfa or MG or yes dare I say FIAT.. so to me I would prefer tinker with a Dellorto or Webber.

nothing better than a carb you can change idle and main jets in without any dis-assembly.

 

 

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Daled, you are a sick individual. FIAT...... I will admit they run strong but to me it would be like working on a double knocker Ducati race bike. 

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Daled, you are a sick individual. FIAT...... I will admit they run strong but to me it would be like working on a double knocker Ducati race bike. 

 

Rude one,

Ive been called worse, but that's ok,

never touched a duck, love the desmo concept though... (its Italian so I would love it)

oh, and I got my little FIAT 850 doing high 14's at the local strip...well to be honest...once.....I broke the half shaft on my second launch !

you should have heard the crowd....so many insults...so little time....

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Just to add for people who have cv carbs. CV carbs are common on Harleys  and I was reading over their thread and I saw a common mod. They enlarge the slide hole. I thought I will give it a try, so I drilled the slide hole to 1/8" to enlarge it. Throttle response improved noticeably.

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