Accusump

Author
Discussion

scooby151

Original Poster:

358 posts

184 months

Wednesday 18th February 2015
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Anyone has an idea what size of accusump is ok for a 1300 please? I want to try and avoid a dry sump. :-) if anyone has one for sale, please let me know. Cheers

splitpin

2,740 posts

205 months

Wednesday 18th February 2015
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scooby151 said:
Anyone has an idea what size of accusump is ok for a 1300 please? I want to try and avoid a dry sump. :-) if anyone has one for sale, please let me know. Cheers
Especially given what you use the car for and what you need spec-wise (i.e. short duration and the less dead weight the better) I should say that's a very smart move: doubtless LCM will know and hopefully he'll be along soon.

Cheers

Trev

scooby151

Original Poster:

358 posts

184 months

Wednesday 18th February 2015
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LCM

444 posts

204 months

Thursday 19th February 2015
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A long story, BUT.

I've never used one on a Radical (always relying on their "dry" sump system). But, following a "discussion" with Uncle Ted, introduced them to Forceworld where they are gradually catching on. When I first tested his wonderful 1598 in my Force (which has a wet sump) UT complained about serious oil surge and its effect on OP. This was not unexpected as both Long and Lat Acc are higher in a Force LM that a Rad. But, being a curious (and peculiarly data rational) sort of bloke, I compared the OP of the wet sump Force with the dry sump Radical under very similar conditions (similar fluid temps, same points on the track at similar velocity and acc [though the Force v inst and acc figures were somewhat higher]). Surprise, surprise - the R dry sump figures were even worse that the Force wet sump!

The sump pan on a Force is structural so realisticaly one is stuck with a wet sump. We played with oil levels and baffling with some success in the Force but decided to bite the bullet, make a fundamental intervention and fit an Accusump. That was 4 years ago and it has functioned perfectly ever since. Reading the AIM data it is clear where OP starts to drop in opposition to rising rpm (surge) and just as clear when the Accusump cuts in and puts a floor under the sagging OP.

I use a 2 pint/1 litre tank with a 40psi electronic valve (which is not the standard supplied with the kit so has to be bought as an extra). Once fitted the system is invisible save that one needs to remember after a session to run the engine at reasonable revs for a few seconds before switching off. This will take the OP above the valve trigger point and so recharge the tank with pressurised oil.

scooby151

Original Poster:

358 posts

184 months

Thursday 19th February 2015
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Thanks for that mate ;-)

scooby151

Original Poster:

358 posts

184 months

Monday 23rd February 2015
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So I am in he process of purchasing one now. All I have to do is to confirm which pressure switch I need.
The on I am thinking is the 20-25psi activation. There are another two however I am assuming that this is the on I would need most. Here is the link to the item, any feedback would be greatly appreciated. Thanks :-)
https://www.merlinmotorsport.co.uk/p/accusump-elec...

LCM

444 posts

204 months

Tuesday 24th February 2015
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It's your money and your decision but I wouldn't bother with a 20 psi switch as on a bad day that could mean an on-power OP of just 15 psi.

I have always used a 35-40 psi switch which on most days puts a floor of 35 psi under the OP and on a rare bad day gives a P min of 2 bar (30 psi in old money). I know it's £250 extra but if you're going to do it surely it's worth doing it properly. angel

BTW I don't come here very often these days so if you need more info it's best to PM me.

scooby151

Original Poster:

358 posts

184 months

Saturday 28th March 2015
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Ok so I had mine fixed today. I have a little question please. When I start the engine , once warm I rev it, the pressure seems to increase all the time. The max pressure I saw is around 120 psi, it was late so I didn't want to bother the neighbours. Is this normal? I mean once the oil pressure drops and accusump kicks in , the pressure reduces i.e. The oil empties.
Cheers

LCM

444 posts

204 months

Thursday 2nd April 2015
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scooby151 said:
Ok so I had mine fixed today. I have a little question please. When I start the engine , once warm I rev it, the pressure seems to increase all the time. The max pressure I saw is around 120 psi, it was late so I didn't want to bother the neighbours. Is this normal? I mean once the oil pressure drops and accusump kicks in , the pressure reduces i.e. The oil empties.
Cheers
Not normal!

If correctly fitted the Accusump should be transparent (I use the word literally and correctly ie although it exists you cannot see it [and therefore the opposite of virtual] rather than its current perverse usage by politicians of you can see it). So your view of OP should be exactly as it was before the A-sump was fitted.

The Accusump should slowly discharge as you start the engine and thus give some initial lubrication. Once the engine has fired and while the oil is still cold the OP at say 2.5k rpm will be relatively high (just the same as before the A-sump was fitted) and the A-sump will recharge and hold its load of oil at say 40 psi.

The only effect that the A-sump should have is putting a floor under sagging OP under surge conditions. You can see this on your AIM or LIFE data when, with hot oil and under high g (Lat or Long, but particularly Lat), you open the throttle, the revs increase and yet OP decreases until it reaches approx the trigger point of the A-sump valve when it flattens out and maintains its floor value until the surge passes, normal oil supply resumes and the A-sump refills.

I suggest taking it back to wherever it was fitted. It could be an installation issue (I have known them to be fitted with the flow reversed) or an OP sensor issue