DirtyMike

I've been playing around with tuning my car. It has a fresh 355 bottom end with forged pistons and ARP rod bolts. I understand the heads may not make power all the way to 7k but I've done a few pulls and it seems to pull hard all the way.

my question is, how far should I push the bottom end on a regular basis. I'm not getting any real knock and the tune is in my opinion on the safe side at the moment. I was thinking of shifting at around 6700-6800k. Anybody here pushing their luck on a stockish bottom end? Lol

SS RRR

iTrader: (2)

Pretty much to the moon. You should be fine with those shift points. Getting it dyoned to see where power peak is will tell you exactly where you should be shifting.

DirtyMike

True, dyno time will hopefully be in the near future. The car feels incredible where it is now. Just don't want to push my luck too much. haha.

SS RRR

iTrader: (2)

Also, as long as you used good valvetrain parts you should be just fine.

DirtyMike

918's on stock valves.

BALLSS

Your rod bolts won't be the weak point....the springs would be more of a concern for me at that RPM...especially if they have over 10k mi on them mi on them

918's have been known to break....sadly I found out

DirtyMike

They have maybe 4-500 miles on them. Hopefully they will last awhile. Lol. Wouldn't be my first time pulling valves out of spare heads. HaHah

BALLSS

I have read WAY more 918 spring failures than any other spring. Lloyd Elliott will not buy, sell or install them due to the failure rate. When a single spring breaks...the engine damage involved typically goes WAY beyond just a bent valve.

I like many got them years ago and did check them at 5k mi intrevals....one of mine became a 2 piece spring. Fortunately the retainer was holding that coil together as it separated in my hand when I pulled the spring

springs are wear items with aftermarket cams...

Consider the Lunati LT1 kit when you decide to replace the 918's

DirtyMike

Thanks for the advice. I will definitely upgrade when I get some nice heads later on