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LC 308 V8 Redline?

Started by _rorym_ , Nov 08 2005 08:48 PM

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28 replies to this topic

#1 _rorym_

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Posted 08 November 2005 - 08:48 PM

I am a bit lost on what guys are using for a redline on a warm 308. This thing spins to 5000 rpm in the blink of an eye and totally faster than my 300kw SV8 because of the weight.
Rory

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#2 _munro_

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Posted 09 November 2005 - 01:07 AM

cam ,heads ,carberation and exaust control engine charictoristics like horsepower power curves and so forth crank and flywheel are big factors in torque figures
rings, bearings, pistons bolt kits and counter balance (combo of engine balancing, harmonic balancer, and flywheel) allow for durability

ie a motor that has heaps of head cam carb and exaust work done will go like a bat out of hell and may rev to 7 or 8 grand but won't be reliable

so you really need to know what quality parts have been used in the last rebuilt

hope that helps tom

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#3 _rorym_

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Posted 09 November 2005 - 06:39 AM

Oops! It is newly rebuilt red 308, heads and block decked,converted to unleaded seats, Edelbrock Performer,Quaddie, basically fairly stockist, balanced. Standard redline in a 308 is 5,500 rpm isnt it? This thing gets to that in a blur in ALL gears, feels like it needs 5th and 6th out of my SV8!.
R

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#4 warrenm

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Posted 09 November 2005 - 07:16 AM

The redline should be where the max HP starts to drop, best determined on a dyno, via times or seat of the pants at the track.

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#5 _workinprogress_

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Posted 09 November 2005 - 07:49 AM

yeh i agree. The best way to get the redline would be a dyno test. Even using 5500 an a stock engine as a redline could be wrong as the engine may have had a lot of wear in it. I know my 202 doesnt like reaching its factory redline too much and its horsepower drops before that as well. And who knows where its redline would be if the parts arent standard.

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#6 _rorym_

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Posted 09 November 2005 - 08:11 AM

I am out of time for the dyno, got it booked in after this weekend at Noosa. Think I will just stick to 5500 rpm for the weekend, that will be fast enough.
R

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#7 Peter UC

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Posted 09 November 2005 - 03:52 PM

My engine that is being built sounds similar to yours, about 300HP and my engine builder reckons that it is safe to 6500 but its max power would be in 5500 - 6000 range and so is the shift point.

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#8 _rorym_

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Posted 09 November 2005 - 06:54 PM

Thanks Pete,
I will see how it goes but the bloody thing is a grenade.
R

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#9 _Yella SLuR_

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Posted 09 November 2005 - 09:11 PM

Bout 5,000 RPM. It will creap up to 5,500RPM a bit slower, but still fairly easily, but it's over the power range for the cam, so not much point.

Being an LH, I might be carrying a bit more weight than you.

Edited by Yella SLuR, 09 November 2005 - 09:18 PM.

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#10 _rorym_

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Posted 09 November 2005 - 09:26 PM

Problem is it wants to go further and is still accelerating because of the power to weight ratio. Like I said, blink and we are at 5000rpm in 4th, where are my other 2 gears?
R

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#11 _[BOTTLEDUP]_

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Posted 10 November 2005 - 01:46 AM

What rods and rod bolts have you got? I wouldn't push the std rod bolts and 'unprepped' rods past 5400 very often... :S

As mentioned before ideal max rpm is a few 100 after peak power.

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#12 _EXLXSL_

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Posted 10 November 2005 - 05:24 PM

Also, as the revs go up, the chance of pushing a pushrod through a standard pressed steel rocker increases.

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#13 _workinprogress_

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Posted 10 November 2005 - 05:31 PM

well if you wanted more top speed then you could keep your redline low and change your diff ratio. Or go with some larger wheels

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#14 Heath

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Posted 10 November 2005 - 06:00 PM

I think a different diff centre is the way to go for you... Larger wheels will take away the classic look of the vehicle and may cost a fair bit when you include tyres and stuff. And they may not even fit well

Find out what options for diff centres you have, Rory.

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#15 _rorym_

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Posted 10 November 2005 - 06:18 PM

A2 sold me a 3.08 diff that is showing 23kp per 1000 rpm, ie 90 kph @ 3800 rpm. Something is seriously wrong here. I think the tacho is way out.
. 3.08 diff with 195/60x13 tyres should be 32/34 kp per 1000 rpm.
R

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#16 _workinprogress_

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Posted 10 November 2005 - 06:28 PM

that does sound very wrong. You should be able to tell by the sound of the engine about where the revs are at. You havent perchancer just put this v8 in and taken out a 6 have you? in which case yes the tacho will be wrong. I reckon a 2.76 diff would serve you alot better than the 3.08 one if you are having trouble with it.

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#17 _[BOTTLEDUP]_

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Posted 10 November 2005 - 06:45 PM

Sounds like a 6 cyl tacho to me dude... :huh:

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#18 Heath

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Posted 10 November 2005 - 07:23 PM

haha I was just about to say exactly the same thing mate. It would also account for the loads of power left over after that RPM

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#19 _rorym_

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Posted 10 November 2005 - 08:21 PM

Work, No mate, its an LC, I took a V8 out to put a V8 in. Doh! The diff is fine, the revs are wrong. I will put you in V8 Supercar some time and get your to tell me the revs it is at as it is bellowing your brains out of each ear like this thing does.
Heath, Its an older Autometer with shift light, I opened it but there is no 4/6/8 clicker. I will get it checked at the auto elecs in the morning on the way and if its wrong, which I reckon it is, I will throw a VDO unit at it.
R

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#20 _Bomber Watson_

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Posted 10 November 2005 - 09:34 PM

didn't harry firths variant have a 2.73 in it??? and from what i heard through aussie muscle car, they used to take off in third no wakkas with the 308....just somethign to think about.