cam question

[Looneybomber]

I figure Float_6969 will check this out.

Hey dude i was thinking. youre guna be putting in new rings and stuff in your engine. While u have it torn down, what about changing the cam? If u went with something of a long duration (say 264-270) but stayed with a mild lift (say 8.5-8.8mm) U could keep from upgrading your valve train, ull lose some low end (way too long of duration and will probably get soot all over in your exhaust from the unburnt gasses at low rpm from all the valve overlap) But it will breathe real well up high. I dont know how the scavagging effect works on turbo engines, but I assume its just like NA engines. Only thing im wondering is if because youre under boost u wont need as long of an overlap and that duration i mentioned might be to long?Tell me what u think?Also i dont know how much that would kill the low end, if its too much it will suck for autoX cuz your torque band wont be smooth enough

[biosehnsucht]

8.5mm-8.8mm should be fine as these are the lifts for the Tomei cams intended for use in stock valvetrains.. check out http://www.tomei-p.co.jp (they have an english section!) to see what I'm talking about.

but those are some wild durations you'll definately free up the top end but will probably hurt at least a bit at the bottom... but I have no actual experience in this so someone who does should chime in...

[Jezz_s13]

the std exhaust is 8.5mm and I'm running a 256/8.8 intake with no problems.

There are quite a few people in the uk running 264/9.0 mm on std lifters/springs etc but the uk rev limit is only 7.2k, the JDM is 7.7 so not sure if the std head gear will cope with those kind of revs with 9.0mm, I guess it probably would being designed for JDM etc, maybe ask your HKS dealer what they recommend. All of the HKS cams are designed for hydraulic lifters, Tomei do two different types solid and hydraulic.

I think more than 9.0mm you have to machine the head anyway to stop the cam lobes hitting stuff.

I can't really comment on bottom end power as most people with the wilder cams are running biggish turbos and very free exhausts anyway so difficult to say what would be the cause of poor low down torque as all would contribute. I don't doubt it has some effect though, but even 264 is still quite tame in terms of N/A.

[Looneybomber]

Well I know Float_6969 has some 80mm exhaust (apexi N1?) that he hasnt installed yet. So hes guna be pretty free flowin. Not sure what turbo he has planned for it though. Nothin too huge cuz i know he wants it tame enough to autoX.I was hoping that punk would respond before he left for 2 weeks, but he didnt.

[Jezz_s13]

I have an N1 waiting to go on too LOL, been sitting in my lounge for almost a year all shiny and new.

[float_6969]

I plan on running 264 @ 9.0. To make up for the lost power in the bottom end I plan on running a high compression setup. I'll have to wait until I have the money for standalone before I can do all of this as I will need a way to base the timing off of the boost, and not the rpm's. Until such time, i'm going to fix the rings and call it good. I'm more worried about suspension right now. The stock suspension with 215,000 miles on it just isn't cutting it for me. Anyway, thats the plan...

[Looneybomber]

Ahh yes the elusive 100mph we both keep trying to hit in that long right hand sweeper. Im sure once u dump that stock setup u will be golden.

[float_6969]

I'll see triples in that turn again. I WILL! Hehehe