Smoother ? Tough call , they both have a great torque band but the 8 port 421b just goes insane crazy after the mid , I guess my answer is p5xl with 15009T or 15007T or 15009HT

Plus 4 have standard button installed , plus4C have turbo button installed

have u had chance to do examination yet:lol::lol::lol:

any benefit to 15007t in 421 ?
maybe 421 crank in NR or BF ??

Probably tonight L.


I went and ran some electric 4wh and 2wh yesterday and then a party for my sister in law til 4am , tired still . Going over to moms for some sturgeon now , yum yum .

Hold on to your pants!!! Yes , 8 port with one of the tuned cranks is craazzyy !!

421 crank in bf :)

421 crank in bf :)[/QUOTE]

hmm better than p5 crank ?
Is the 8 port case the Bf is in the same as 421 case ???

Yeah, something must be off. I set the idle gap as suggested and that was about the same. Then set the HSN and LSN to the 3.75 out from bottom and that brought the HSN about flush and the LSN a little in from flush.

The motor would not even fire. Fuel just started pouring out from the pipe. From there I leaned the bottom until it fired (about 1.5 full turns) then checked the top and the engine would die as soon as I pulled the trigger. I then leaned the HSN until I could get to full RPM(again about 1.5-2 full turns).

Now I have a good idle, the motor can pull to full RPM with plenty of smoke, and the pinch test will stall the engine at about 5-6 seconds. I still have yet to see what it does on the track but on the box its at about 170 max so it would seem about right at about a half tank of running/tuning.

This engine has about 3 gallons on it. Maybe a little more.

I think its about there but the settings just seem to be very odd.

I did say this was an FMS with a P5 carb right?

I can say this... This engine has never flamed out or cost me a race. It has ALWAYS started, idled, temped, ran fine but I just could never get the bottom dialed like I believe this thing is capable of. I also have a P5 and the bottom end is very nice but could use a tad more top end on the larger tracks.

Thanks,

Dan

hmm better than p5 crank ?
Is the 8 port case the Bf is in the same as 421 case ???[/QUOTE]
Not exactly , thenewer 8 port cases have extra diverters in the transfer ports

The 421b just used a 5port case (they call it 3port case)that they put a splitter in the rtear main intake to match up to the sleeve .

Both cranks are very similar I'm sure but the 421b is probably a super comp crank with afilled intake ramp , the 15009 (p5 crank) is a lighter crank because it is drilled or cast through the intake opening and creating an air pocket that is kinda engineered to do something specific ;)

Did you pull the slide barrel out while doing the low speed adj. ? ;)

Common mistake

Nope...Can you explain that. I am not a good tuner:eek:

http://rcspecial.com/news/?p=35530 http://vimeo.com/7595905
When setting the lsn , pull the slide barrel out as if applying full throttle , turn the lsn all the way in until it stops (not too hard) then back out and count the turns until you get to desired settings.


So you're at 2.5 turns out from bottomed out on the hsn now ? That doesn't sound right but the pinch test does .

Something to help up top

Monty, when are you expecting more 21-7fms motors?

Thanx...

Monty on the engine i gots form you what pipe/ header did you say to use in buggy?

I have one coming monday , if you want one lmk asap !!! There is one more available at novarossiusa if you want me to get it

I like 9886/41021 or dynamite 086hs

If you want extra lowend use 9853ss/41005 - truggy ;)