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How bad is this oil surge?
cloudy - 15/7/09 at 07:21 PM

I'm in the process of making a baffled sump, but not sure it'll be ready for a trackday on saturday...

I've just fitted R888's and the level of grip has made me worried about oil surge, particulary under braking. I've just taken a warm R4 round the block through some twisties. The drops in the graph are brake tests from 60 to zero. I think the dip on the far right is a drop to idle, though i'm not 100% sure. I know the graph isn't ideal - but am I likely to do damage driving the track day like this? Rescued attachment surge.png
Rescued attachment surge.png


mookaloid - 15/7/09 at 07:26 PM

are you likely to lots of braking from 60 to zero on a track day?

perhaps do the test without these brake tests and see if the pressure drops as much?


cloudy - 15/7/09 at 07:27 PM

perhaps not to a stop, but heavy braking is heavy braking, I can't do 100>50 on the road can I


locoR1 - 15/7/09 at 07:37 PM

Have you done a sensible drive to compare the graphs?
Could be just normal oil pressure fluctuation due to change of engine rpm


mookaloid - 15/7/09 at 07:42 PM

quote:
Originally posted by cloudy
perhaps not to a stop, but heavy braking is heavy braking, I can't do 100>50 on the road can I


Ok fair point - is that a minimum of 38 psi?

If so it doesn't seem too bad to me.

I think the main problems with oil surge are when you lose pressure on a long corner with the engine under load, which doesn't seem to be happening here

Cheers

Mark


cloudy - 15/7/09 at 07:44 PM

"a sensible drive" not familiar with this terminology?

Here's another run before tyre swap, two drops I know equate to medium braking for two corners Rescued attachment surge2.png
Rescued attachment surge2.png


locoR1 - 15/7/09 at 07:49 PM

quote:
Originally posted by cloudy
"a sensible drive" not familiar with this terminology?

Here's another run before tyre swap, two drops I know equate to medium braking for two corners


I half expected that reply

looks ok to me but as said by mookaloid its your long fast corners that are the real engine killers!


cloudy - 15/7/09 at 07:58 PM

Will try and find some big roundabouts! I'm getting the feeling that it'll probably be ok for a few sprints until I make and fit a baffle...

James


mark chandler - 15/7/09 at 08:09 PM

Can you not graph with respect to RPM, you can then see if its an issue.

Regards Mark


s2gse - 15/7/09 at 08:15 PM

how are you doing the graph what program are you using to get oil pressure info


cloudy - 15/7/09 at 08:17 PM

To answer both posts in one go it's a digidash2 lite, so can only log one channel... I could take a GPS log at the same time I suppose...

James


afj - 15/7/09 at 08:30 PM

can you look at the graph after a session on track, take a laptop i mean


cloudy - 15/7/09 at 08:44 PM

Will do, I presume i'm looking for any drop below 30ish psi (idle hot pressure) whats dangerous? I presume 0psi for any time at all is terminal?

James

[Edited on 15/7/09 by cloudy]


procomp - 16/7/09 at 06:49 AM

Hi

I will make no comments on the pressure or how to do the test. However on the RGB forum there is one guy who runs a data logging overlay on his videos. Tim Hovred. His videos will clearly show his oil pressures temperature and G forces over a full race. This may give you an indication of what affect the pressures in different situations.

LINK TO VIDEOS.

HTH
Cheers Matt


cloudy - 16/7/09 at 09:07 AM

Thanks Matt, that's a good comparison to see "normal" figures

Interestingly his just stays very static, doesn't change even when revving or idling? I'm sure bike engines don't do that normally!

[Edited on 16/7/09 by cloudy]


matt_gsxr - 16/7/09 at 07:47 PM

James,

Oil pressure on these GSXR1100's is a bit strange (as you probably have noticed).

At idle when cold mine is way high (100psi or maybe a bit more), the manual suggests it should be lower, but I swapped the pressure relief valve and it made no difference. Subsequently rf900rush confirmed that this is what they do. (rf900 has similar bottom end to GSXR1100, different clutch FWIW).

I haven't used mine enough to recognise pressure changes with cornering so I can't comment (and my engine is the other way around to yours), although when I talked to the side-car chaps they suggested a bit of over-filling and a sump-baffle (the directions of force are different in mine, prop and no chain, so I'm not sure on that).

I haven't yet gone around any corners, these are for next week after I have sorted out the straight stuff.


Here is a picture of a sump baffle that I inherited (which fits the GSXR1100W). I will probably use it so can't offer it, but it shows the design. You are not short of design skill I know, but there is no need to reinvent everything (unless you want to of-course!). They used a sump gasket above and below in the standard fashion.

GSXR1100WP SUMP BAFFLE
GSXR1100WP SUMP BAFFLE


Matt

p.s. how did you get your pressure log? Can you show it along with a RPM trace? If those dips are braking induced, then I think you want to get rid of them (but you know this already).

[edited for precision]

[Edited on 17/7/09 by matt_gsxr]