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Old 04-08-2009, 03:40 AM   #1
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Default Stock motor-safe redline?

I have an 05 MSM with a stock engine(for now)and upgraded turbo and supporting mods including a Hydra.
I know this all relative but where do people set their redline for reasonable safety on a stock motor? I know many rod failures(the motors weakest point) occur due to stretch at TDC.
I am current running a tune of about 250/250. I have the redline set at 7200 mostly to make 1st gear more useable.
Do you think this is a reasonable redline? If not where would you set it?
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Old 04-08-2009, 03:42 AM   #2
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isnt the oil pump/gears on thin ice after 7k?
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Old 04-08-2009, 05:15 AM   #3
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On a stock harmonic balancer, the OPGs are pretty much 100% safe below 300whp or 8000rpm. I would worry about stock rods past 7800 or so, as well as the valvetrain in that range. Past 8k, you need uprated valve springs, rods, and possibly billet OPGs.

Having said that, I have my hard cut set at 7200 on my stock 99 motor for longevity, even though it's still making power through to 7500 or so.
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Old 04-08-2009, 12:01 PM   #4
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I didn't find that I needed anything above 7k on the street. I was willing to sacrifice a bit for engine longevity. I set my soft cut at 6800 and hard cut at 7000. I hit it occasionally taking a long stab in second... but never missed the extra couple hundred RPM I could have had.
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Old 04-08-2009, 12:43 PM   #5
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Quote:
Originally Posted by 18psi View Post
isnt the oil pump/gears on thin ice after 7k?


There are ALOT of guys running more R's then that for extended track time. The gear failures are a pretty small and specific subset of people making alot of power and running high RPM.
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Old 04-08-2009, 12:56 PM   #6
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I have mine set at 7500.. no problems. There were a couple of guys here in Ga that funked with the stock ECU on STOCK n/a Miatas and were revving a little over 8,000RPM and were saying how it was all reliable... both of them have funked their motos within a year of doing it
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Old 04-08-2009, 01:00 PM   #7
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Ok it sounds like I am in relatively safe territory. Savington, you mentioned on the "stock" harmonic balancer that the oil pump gears were safe up to a certain RPM. Does something like the ATI balancer make that big a difference for longevity/durability of the oil pump? I guess I hope it would for $600.
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Old 04-08-2009, 02:18 PM   #8
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From what I read changing to an aftermarket balancer actually causes the oil pump to fail.
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Old 04-08-2009, 02:24 PM   #9
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I think changing to an aftermarket pulley that does not have a harmonic damper has been generally linked to oil pump failure. Specifically, the aluminum "underdrive" pulleys that you see from time to time are of a solid construction and do not incorporate a damper. I'd imagine that the ATI unit would be good as gold in this regard.
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Old 04-08-2009, 03:46 PM   #10
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I think changing to an aftermarket pulley that does not have a harmonic damper has been generally linked to oil pump failure. Specifically, the aluminum "underdrive" pulleys that you see from time to time are of a solid construction and do not incorporate a damper. I'd imagine that the ATI unit would be good as gold in this regard.
Youre right, I was thinking aftermarket pullys.
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Old 04-08-2009, 03:54 PM   #11
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I'd imagine that the ATI unit would be good as gold in this regard.
Matt Andrews just lost a set of OPGs in his time attack car recently. I believe he was running an ATI damper, although I don't know how much power he's making.
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Old 04-08-2009, 04:11 PM   #12
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Quote:
Originally Posted by Savington View Post
Matt Andrews just lost a set of OPGs in his time attack car recently. I believe he was running an ATI damper, although I don't know how much power he's making.
interesting. please bring us more known and factual information to corroborate your beliefs.

in the meantime, I will maintain my plan to install both billet gears and ATI pulley.
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Old 04-08-2009, 05:38 PM   #13
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Quote:
Originally Posted by Savington View Post
Matt Andrews just lost a set of OPGs in his time attack car recently. I believe he was running an ATI damper, although I don't know how much power he's making.
he did not have the damper...but is switching to billet gears for the rebuild.
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Old 04-09-2009, 05:18 AM   #14
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Faglet, was he running no damper at all or the OEM damper?
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Old 04-09-2009, 08:59 AM   #15
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Quote:
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Faglet, was he running no damper at all or the OEM damper?
oem. Don't call me names, they hurt.
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Old 04-09-2009, 09:05 AM   #16
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oem. Don't call me names, they hurt.
Stfu and always capitalize OEM skittles.
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