Lose of power at higher rpms

[LowR3V'in]

i would love to see the power shifting around on a dyno fucking around with cam timing.
dyno time isn't too expensive i would do it, but, m30.

How much did those guys gain about by doing that, digger?

[digger]

you can try contacting tinkerputzer or nando

[whitebulat22]

Just as a data point with my similar Bimmerheads engine, I am at 211 whp on my 2.9 Mahle stroker despite a 5800 rpm rev cap glitch on my megasquirt and stock intake mani / throttle / valves. It has the 284/280 cam which isn't as rough as I thought but I would definitely stay smaller on the cam for a DD- even with a good dyno tune it is barely drivable when cold and with my 8 lb flywheel unbearable in LA traffic.

I would personally splurge on a standalone and / or cam gear rather than dealing with breaking in a new cam again, if my engine is where it is and climbing through the stock throttle then an incognito AFM setup with megasquirt should be fine for 200 whp, and I wouldn't want my brand new engine running anything other than a flawless tune. This will also set you up for ITBs in the future.

[digger]

Just as a data point with my similar Bimmerheads engine, I am at 211 whp on my 2.9 Mahle stroker despite a 5800 rpm rev cap glitch on my megasquirt and stock intake mani / throttle / valves. It has the 284/280 cam which isn't as rough as I thought but I would definitely stay smaller on the cam for a DD- even with a good dyno tune it is barely drivable when cold and with my 8 lb flywheel unbearable in LA traffic.

I would personally splurge on a standalone and / or cam gear rather than dealing with breaking in a new cam again, if my engine is where it is and climbing through the stock throttle then an incognito AFM setup with megasquirt should be fine for 200 whp, and I wouldn't want my brand new engine running anything other than a flawless tune. This will also set you up for ITBs in the future.

that cam has an earlier IVO and later EVC than a schrick 288 but less lift at TDC, it has a fair amount of overlap and is a slow ramp profile which is never good for light throttle and smooth idle, its very gentle on parts though.

[ForcedFirebird]

Can you post or PM the timing table? There might be too much timing at peak TQ, which could cause pre-detonation.

Also, not sure who rebuilt your AFM, but they should be calibrated for spring tension after rebuild. I have seen them freshly rebuilt and needed 4 clicks on the spring to get the AFR proper (shouldn't be an issue with the custom chip, though). Not a bad idea to pop the AFM cover off and make sure the wiper isn't going off the track (seen this in rebuilt AFM's as well).

Guessing when you say "billet" cam, it's an Ireland grind - as they advertise them as billet, but are just new castings that are ground to IE's specs.

FWIW, we have an m20 here at the shop with more compression and it would ping on occasion with when it's hot out (or cheap gas) with a 272/284 dual pattern cam. Pulling a few degrees at peak TQ remedied it.

A healthy m20 doesn't like much more than about 27° of timing at peak, and they do like to run in the 13's for power N/A.

[digger]

Guessing when you say "billet" cam, it's an Ireland grind - as they advertise them as billet, but are just new castings that are ground to IE's specs.

billet is apparently used interchangeably with non regrind these days....