wildert Brian Klausen Ultra Moderator Location: Denmark Join Date: 03/21/2006 Age: Midlife Crisis Posts: 388 Rally Car: VW Golf GTi 16V |
|
john vanlandingham John Vanlandingham Junior Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
What pressure does it light up at? So many OEM switch the light ON at maybe 0,4 bar-0,45bar and with the oil pump I use in the old mighty V4 Saab, it makes 0,4bar pressure even after I have spat the rod bearings out into the bottom of the sump for cylinder 1, and 1mm clearance on cylinder 3.. True story, bro. John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
vbares Vittorio Bares Junior Moderator Location: Londonderry, NH Join Date: 04/10/2007 Age: Ancient Posts: 413 Rally Car: Audi 4k (3b conversion) |
|
Reamer Jeff Reamer Junior Moderator Location: Marlette, Michigan Join Date: 08/14/2010 Age: Midlife Crisis Posts: 489 Rally Car: Subaru |
The allstar performance ones are 20psi not sure how many bar that is? $13 for a light and the sensor. 235 degree water temp light. Those are the only 2 after market guages I have in the car and there not even guages.
First rally 2013 Rally car type AWD subaru Total rallies as driver 6 Total rally cars built 2 Total rally cars caged 3 Total rally cars repaired from offs 4 Total years racing exp other then rally 19 yrs Like 31motorsports on FB! Check out 31motor sales on ebay for used Subaru parts |
Pete Pete Remner Professional Moderator Location: Cleveland, Ohio Join Date: 01/11/2006 Age: Midlife Crisis Posts: 2,022 |
Not precise, but a way to remember is bar = barometric pressure = about 14psi or so, so a 20psi is a 1.5 or 1.4 bar switch.
Look at fuel pressures, most EFI systems are 42-43psi base pressure which is 3 bar, except for a bunch of GMs with the weird central injection which are 58psi minimum which is 4 bar, and CIS which is best not thought about.... Pete Remner Cleveland, Ohio 1984 RX-7 (rallycross thing) 1978 Silence is golden, but duct tape is silver. Edited 1 time(s). Last edit at 12/08/2014 12:54PM by Pete. |
wildert Brian Klausen Ultra Moderator Location: Denmark Join Date: 03/21/2006 Age: Midlife Crisis Posts: 388 Rally Car: VW Golf GTi 16V |
Hm - you do have quite a point - I actually don't remember. The VW has the same 0.4 and 1.8 dual setup that Vittorio mentions for the Audi - but that is long gone. I THINK I have the 0.4 switch - but it is in the head though - and there is quite a difference in pressure from just after the filter, to the cylinder head. Way back when, I used to run a single gauge with two sensors and a switch. The difference was pretty significant, and I seem to recall that I went for the 0.4 in the head for that reason. Brgrds Brian |
Reamer Jeff Reamer Junior Moderator Location: Marlette, Michigan Join Date: 08/14/2010 Age: Midlife Crisis Posts: 489 Rally Car: Subaru |
A 5 psi low oil light is to low oil pressure to save any thing in my opionion. Good idea to maybe have it cut out at 5psi and just signal at 20 psi.
The water temp light saved me at Snodrift this year. We Sno banked and plugged radiator solid. With out the light im sure i would not have know it was hot till it was to late. First rally 2013 Rally car type AWD subaru Total rallies as driver 6 Total rally cars built 2 Total rally cars caged 3 Total rally cars repaired from offs 4 Total years racing exp other then rally 19 yrs Like 31motorsports on FB! Check out 31motor sales on ebay for used Subaru parts |
john vanlandingham John Vanlandingham Junior Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Speaking from own experience TWICE: 20-25 psi switch is too low if you look and the low oil pressure and don't do anything---except say "DOH!" when it finally pops.. John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
Reamer Jeff Reamer Junior Moderator Location: Marlette, Michigan Join Date: 08/14/2010 Age: Midlife Crisis Posts: 489 Rally Car: Subaru |
Damn Subies run around 20 psi at idle! Light will be on at idle if any more then 25 psi. My 20 psi oil light flickers at stop signs when the engine is warm. The old oval track saying was 10psi for every 1000 rpm. So if your reving at 8k with cheap oil and 20 psi chances of scorring a bearing are going to be pretty good. Not sure how much higher then 25 psi you would want before you start ignoring the light at lower rpm's? at least on a subie.
First rally 2013 Rally car type AWD subaru Total rallies as driver 6 Total rally cars built 2 Total rally cars caged 3 Total rally cars repaired from offs 4 Total years racing exp other then rally 19 yrs Like 31motorsports on FB! Check out 31motor sales on ebay for used Subaru parts |
john vanlandingham John Vanlandingham Junior Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
That's more than some cars. Fiats old twin cam motors no more than 6psi at idle was completely normal!! ACK! John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
Pete Pete Remner Professional Moderator Location: Cleveland, Ohio Join Date: 01/11/2006 Age: Midlife Crisis Posts: 2,022 |
And my Volvo's light comes on at 14psi and in the owner's manual it says it is normal for the oil light to come on at idle if you've been driving the car hard, so hold the idle speed up a bit until the engine cools off.
I think the VW system of two different switches is RPM dependent somehow. Like, it's okay if you have 10psi oil pressure at idle because who cares, you're at idle, but if you have under 25psi at higher RPM then you're killing your rod bearings even faster than normal (only applies to 136mm rod engines). I think. Anyway, on the ones I've paid attention to, both switches are screwed into the same oil gallery two inches apart. Pete Remner Cleveland, Ohio 1984 RX-7 (rallycross thing) 1978 Silence is golden, but duct tape is silver. |
wildert Brian Klausen Ultra Moderator Location: Denmark Join Date: 03/21/2006 Age: Midlife Crisis Posts: 388 Rally Car: VW Golf GTi 16V |
It is. The 1.8 bar switch is only "monitored" if the revs are over 2000 rpm. It is also linked to a buzzer, so if you have under 1.8 bar @ over 2000 rpm, the oil light will flash (not be lit - but flash AFAIR).
That is very likely - I can't really remember. I changed that layout years ago when making room for an oil pressure transducer for the pressure gauge, as well as a temperature sensor. Brgrds Brian |