Whats everyone's opinion on raising the redline to 6800rpm or 7000rpm on an LD9? Built bottom end, turbo, head work includes p&p, ss valves, bronze valve guides, secret cams. Decently safe to do, or pretty risky?
12.6 @ 114.6 MPH
Id say it's ok considering it's built. My ecotec was raised to 7k when it was bone stock and had no issues. As long as you have a good tune you should be ok
Matt I plan to rev mine to 7,000rpm, but "tell" it to shift the auto at 6850. You have to make sure your shift speeds are correct at the correct RPM and correct MPH or it will not shift at WOT and keep revving higher and higher.....even with a rev limit set....
I would set it lower at like 5,000 and get it to work there, and then tune it up to 7000 .
Getting to shift at higher RPMs can be a BIG pain in the ass if one setting is wrong.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
Valve springs and the oil pump play in to this...
A general rule of thumb here is:
If you have stock LD9 valve springs AND/OR the stock oil pump... DO NOT REV PAST 6800... (or you will have valve float, and the oil pump will start to cavitate the oil)
If you have Sealed power HO Springs, AND the 2.3 oil pump.. DO NOT REV PAST 7200 (or you will have valve float)
If you have GM HO Springs, AND The 2.3 oil pump. You should be clear to rev up to 8000... (however unless you have my cams, you probably shouldn't go above 7500)
Good to know. I don't plan to change the redline until the tune is finished and I get it on the dyno to see if there is even a need to raise it first. Thanks for the info guys.
12.6 @ 114.6 MPH
why not base it on your cam duration? find out when you stop making power in the rpm range. No point in reving past power.
1999 - Cavalier - 5speed - Exhaust - 17" rims - carbon fiber hood - the beater
User Chemical wrote:why not base it on your cam duration? find out when you stop making power in the rpm range. No point in reving past power.
See my last post right above yours ^ I have no way of knowing where my powerband peaks just based on cam duration. Theres more to it than that, hence when I said I want to get it on the dyno before changing anything with the redline.
12.6 @ 114.6 MPH
EVILution (KGM Godfather) wrote:Id say it's ok considering it's built. My ecotec was raised to 7k when it was bone stock and had no issues. As long as you have a good tune you should be ok
Yea but...
L61 > LD9
Buddy Club Ecotec Cavalier
* More to come *
o'rly
Lets not start this ish up again...
The stock LD9 oil pump starts cavitating at 5800 plus the shafts are spinning twice the speed ouch, but smoothes everything considerably. This motor is a stroked beast with a small top end to make it "Quick" at low rpms to reach its powerband fast.
At what rpm's were the early 90-94 LD2 (automatic) and LG0 (manual) camshafts powerbands and what were their redlines?
