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Re: FX Holden Race Car Project
Posted: Mon Dec 21, 2020 9:37 pm
by 'quipt4it
vlad01 wrote:Yeah I mean actually driving/racing.
VR alternator is actually 85A, says so on the housing, its the VS onward that were 140A, I think? or maybe it was 100A?
I need another VR one as they are the only type for Buick that you can get underdrive pulleys for, don't want my alternator exploding with the engine revving over 7K. Max is 18K rpm for the alternator, stock pulleys I'd be doing about 23K, 5K over speed!
Close on the VS V6... 125 AMPS @ 11.5V/ 5300RPM
V8 only a lowly 85 AMP
Re: FX Holden Race Car Project
Posted: Mon Dec 21, 2020 9:42 pm
by vlad01
85A is plenty for a electrically basic car as the VN-VS. Its not like a young kids 4x4 with light bars and subwoofers, CB radios and shit.
Re: FX Holden Race Car Project
Posted: Mon Dec 21, 2020 9:47 pm
by 'quipt4it
vlad01 wrote:85A is plenty for a electrically basic car as the VN-VS. Its not like a young kids 4x4 with light bars and subwoofers, CB radios and shit.
Wouldn't mind more on mine.
Engine idling, parkers on, tap the elec windows switch and dash lights dim.
Battery shows over 13.5V when running.
They changed to bigger (120A) on VT 5.0
85 AMP good for Toranas FTW
Re: FX Holden Race Car Project
Posted: Mon Dec 21, 2020 11:22 pm
by 'quipt4it
Always enjoy looking in on your build posts.
Lots of ingenuity and forward thinking
Re: FX Holden Race Car Project
Posted: Tue Dec 22, 2020 8:21 pm
by Holden202T
vlad01 wrote:I need another VR one as they are the only type for Buick that you can get underdrive pulleys for, don't want my alternator exploding with the engine revving over 7K. Max is 18K rpm for the alternator, stock pulleys I'd be doing about 23K, 5K over speed!
lol hate to think what im spinning it to then
'quipt4it wrote:Always enjoy looking in on your build posts.
Lots of ingenuity and forward thinking
Re: FX Holden Race Car Project
Posted: Tue Dec 22, 2020 9:11 pm
by vlad01
Depends on the balancer to pulley ratio. I have seen a few alternators explode when pushing them, especially the external fan type.
Re: FX Holden Race Car Project
Posted: Wed Dec 23, 2020 6:31 am
by v6bucket
I have a collection of fans with bent or cracked fins, I am running the motor to 7200, I fitted a larger pulley on the alternator & smaller on the crank, now when the engine is started you have to rev it over 2000 to get the alternator light off.
Re: FX Holden Race Car Project
Posted: Wed Dec 23, 2020 8:11 am
by immortality
Clarko's sell oversized pulleys to suit our alternators.
Re: FX Holden Race Car Project
Posted: Wed Dec 23, 2020 9:14 am
by vlad01
You only need a 20-25% reduction if going at and around 7k, so that means the idle needs to increase to 950rpm to maintain stock alternator rpm on a v6.
Not going to be an issue on mine as my idle is going to be around 1600rpm with the cam I plan to run.
Re: FX Holden Race Car Project
Posted: Wed Dec 23, 2020 10:02 am
by Holden202T
i haven't measured the alternator, but i know the crank pulley is 6 inches, this motor will be going to around 7500rpm.