the ninja pipe and manifold

I don't know which one you're talking about but I run the MR21BO1A with a Tsais T32X and it is A-freakin-mazing!!

Some guys say running the Ninja with 20% or 25% is as fast or better than using the 30%. Is this the myth I been thinking of for the longest while that 30% really isnt necessary except for 8th onroad? Also, since I plan to get one I'll be going with Rocket Science 20%. Now the rule of thumb to step down to a colder plug when using 30% say for example a #7 can this same plug be used with the 20%? Any removal of shims needed?

Are you talking of a .21 or a .12?

If I suppose, you're talking of a .12, if you want to go with 20%, switch to a #6 plug (hotter) and remove one .10mm shim from your setup (you should be around .45mm of combustion chamber height).

If is from a .21 I don't see any reason to go lower nitro content unless you're facing runtime problems.

Corse-R - Sry for not clarifying, but yes I was refering to a .12. Is the .45mm height recommended for any .12 or the Ninja in specific.

This was the setup of a Ninja I borrowed from a friend this weekend for a test. Testing was done at around 2000ft high with a 16% nitro.

From 16 to 20% isn't much difference so you can leave this height and test.

Anyone know the heat range of Ninja plugs? I'm assuming 5, 6, 7. Hottest to coldest. I feel I need a hotter plug and I got a couple of 5's, was running 6,but they didn't change my tune much at all, and eyeballing them the 5's look virtually identical to the 6's to me.

FWIW, I'm running right at 5000ft alt. w/30% nitro. To get it up on the pipe it seems like I'm having to run on the lean side.

...

Here's a question. I have the Ninja .12 and ran it with 30% Mugen fuel. I added that shim under the head before it saw a drop of fuel. I am bumping down to 25%. Should I remove the shim and go with a #6 plug? ( I was running that hot #5, and had a #7 at one point but dind't have time to tune it)

im going down from 30 to 20 (yes i know you should not do this)and iv taken out the shim,
in my nova motors i ran 25 with out putting in a shim and it was ok.
30%is just to hard to tune in the cores of the day,
and now going down in nitro % the motor will probably be slow but it will run
ill just have to get another motor.

Ron Hopkins from Werks Racing says that this thing about "lowering nitro % being a bad thing" is just a myth...

i hope so
and isn't ron hopkins a singer

I heard about that too. I also shown that 20% in a fast motor isn't going to make it any slower than using 30%. I ran against a Sirio Evo 3 STi on 20% and it was flying! I too will bump down and enjoy a longer lifespan on my motor.

Last year the runner-up in the Dutch Championship, drove 1 race with 16% nitro, instead of 25....

He won that race, and only noticed it was 16%, when he returned the can, and saw that he was missing a 16% can, instead of 25... (he has his own shop, and sells fuel)

Yes, you will notice it, but the difference is not that big.....

well this is good to know
i feel better now
was that guy a Dutch guy (like me)
and was he using tornado