RB25 Neo limiter issues

[e30h26]

I haven't been able to find any definite answers on this one........are people aware of any issues with the Neo valvetrain design of shim-on-bucket for drag/drift purposes? In terms of 2 step/launch control or hitting the limiter. I know the JZ folks change to a solid lifter setup but I haven't been able to find any info on something similar for the Neo engine.

[ltcree]

I've been looking at doing a 2.8 with a neo head and I've asked my engine builder the same thing. Apparently you can basically just use rb26 shim under bucket setup, haven't gone into if anything needs modifying or custom parts though.

[iruvyouskyrine]

If you are referring to spitting a shim etc then i have only ever heard of 2 neos doing it, and that was both second hand information on this forum. Simon-S14 said he has seen 2 drift cars do it but they both had fairly large drop in cams with a completely standard valve train. Personally i have been running a neo head for 2.5 years and give it absolute hell on the street and (drift) track and have never had an issue. I run a completely standard valvetrain and cams though.

[GTSBoy]

I think you would probably have to be belting the crap out of the lifters with cams with horribly aggressive ramp rates (probably coupled with inadequate springs) to have much likelihood of it happening.

[AngryRB]

My advice from engine builders was a set of performance valve springs and a general overhaul would be all thats needed which got, he was pretty much assuming the worst situations, which i reminded him it was only street car...

[e30h26]

5 hours ago, iruvyouskyrine said:

If you are referring to spitting a shim etc then i have only ever heard of 2 neos doing it, and that was both second hand information on this forum. Simon-S14 said he has seen 2 drift cars do it but they both had fairly large drop in cams with a completely standard valve train. Personally i have been running a neo head for 2.5 years and give it absolute hell on the street and (drift) track and have never had an issue. I run a completely standard valvetrain and cams though.

This is exactly what I wanted to know. Been hearing to many "oh yeah, a mate's brother's girlfriend's cousin once had the shim fly out and kill a baby" stories.

5 hours ago, GTSBoy said:

I think you would probably have to be belting the crap out of the lifters with cams with horribly aggressive ramp rates (probably coupled with inadequate springs) to have much likelihood of it happening.

I'm planning on getting the Tomei Poncam Type B cams.

"PONCam Set Type-B, Exhaust Duration: 260, Exhaust Lift: 9.15mm, Intake Duration: 260, Intake Lift: 9.15mm"

I can't see those being too aggressive since Tomei list them as "drop in".

[STATUS]

Never had this issue in 7 years.

[e30h26]

15 minutes ago, STATUS said:

Never had this issue in 7 years.

What are you running in terms of cams and springs? What's your engine normally put through, street/drift/drag.....

[89CAL]

What are you running in terms of cams and springs? What's your engine normally put through, street/drift/drag.....

He is/owns a performance shop. I'd say his experience is over many years and many cars.

[89CAL]

What are you running in terms of cams and springs? What's your engine normally put through, street/drift/drag.....

He is/owns a performance shop. I'd say his experience is over many years and many cars.