A ? for the 4 stroke experts!

[Dubblerage]

Per my other thread, I got my head ported on my 07 carb'd Nytro. The dying question I have for anyone who might be able to tell me is:

Since I had this head ported (I can only relate this to 2 strokes, so that's why I'm asking) will this rev higher if it were making more power or would it stay in the same rpm range at full throttle since I did not change any of the cam timing?

I'm askign this because I can't get a very good read on the tach to see exactly how high it steadily revs at full throttle. I've bouncd off of 8900 rpms a couple times, but mostly stayed consistent at about 8500-8600 rpms while holding it open and watching for ditches and deer! I thought it was supposed to be around 8400ish stock, is that right? Any inputs is greatly appreciated.

 

[Dubblerage]

Anybody? everybody? Somebody?

I wish I was a 'jean-yus' then I would already have this thing figured out!

 

[skippyspad]

I don't think it will give you higher revs. You just opened it up so it can breath and get there faster.

Mike

 

[hossZ28]

You may have to re clutch as you have probably mov ed your powerband higher into the rpm range stock you want to see about 8400-8600 rpm

 

[livewire_101proof]

not much of an answer for you but how bout gearing? the nytros are less power than others out there but still have pretty good speed until they hit their wall in the top end. i always assumed that with a little less power they just re-geared for it so you wouldnt notice much until top end. if this is the case then with more power/torque, maybee you could gear up and still have enough power to pull on the top side.
also agree with the power band may have changed, maybee some dyno time would benefit you greatly so you knew where the band was and could clutch accordingly.

 

[kviper]

It would be my guess that being you have not changed caming in any way that your peak's will be roughly at the same rpm range. Your wot shift rpm may be and should be higher if you did actually gain some HP. As stated earlier i would have it dynoed so you know exactly where you are at. A rate of $100/HR for Dynoing sound's like a lot but one hour for what you need should easily answer your question's and take the guess work out of clutching. kviper

 

[pro116]

I would dyno it but stock they make the most power around 8600-8700.