Guest JohnTLT Posted May 11, 2008 Share Posted May 11, 2008 Hi guys, I'm running a HKS T51R KAI on stock head, cams & intake. I might have some mild cams, I'm not sure. Anyway they are probably nothing bigger than 256 at best. I'm running two stages of boost, 0.9 bar & 1.5 bar, but when running 1.5 bar it's like the engine runs out of air when hitting 6000-6500 RPM. It's literally like hitting a wall, it completely stops pulling hard. I'm running a 7K rev limiter. When looking at my Apexi PFC the injector duty cycle never goes above 80% so I have enough fuel. Knock values are also fine. Am I right when thinking the cams and intake manifold/TB are the cause of my problems? Or is there anything else I'm overlooking? The thing is that I don't feel it's always been running out of top end performance like this.. This might just be my paranoia kicking in though. I probably haven't been going at it quite like I did the other day when i first realized this issue. Went to the strip and gave it all it had. Don't get me wrong I have been given it a beating on the streets numerous of times before, just not quite as much as on the strip (on high boost anyway). To cut to the case, I'm looking to correct this issue - only thing is that I'm on a limited budget. I'm looking for a setup that will run strong past 8500 RPM even at 2.0 bar (or close to it). A few questions: How big cams can/should I fit, without doing the valvetrain & porting? Will my current (800cc) injectors work with aftermarket Intake manifold (virtual works) & fuel rail? Quote Link to comment Share on other sites More sharing options...
JamieP Posted May 11, 2008 Share Posted May 11, 2008 Being on a "limited budget" and reving to 8500rpm dont mix, id look at finding out what cams you have then move from there but keep the rev limit as is. all imo of course. Quote Link to comment Share on other sites More sharing options...
Guest JohnTLT Posted May 11, 2008 Share Posted May 11, 2008 I've seen lots of guys reving 8K on stock valvetrain. (I'm running a built bottom btw.) In a perfect world I would be doing a complete valvetrain with OS valves, springs etc. unfortunately I don't have the budget for that right now. In short terms I'm looking to fit aggressive cams, intake, & fuel rail. Quote Link to comment Share on other sites More sharing options...
paul mac Posted May 11, 2008 Share Posted May 11, 2008 unfortunately I don't have the budget for that right now. In short terms I'm looking to fit aggressive cams, intake, & fuel rail. think you've answered your own question there mate, as Jamie says if you are on a budget leave the rev limit where it is, even with a built bottom end (dont know what your spec is) you run a serious risk of blowing/damaging the motor and at 8500 rpm if it lets go the engine will probably be a write off, its not power that kills engines its revs Quote Link to comment Share on other sites More sharing options...
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