Duke

I agree that 50 hp sounds much by itself but there's always a substantional gain no matter the engine from going to dry sump.

JET951

Im not seeing it.

Im certain Milledge would recommend a dry sump for oiling purposes first and foremost not because it makes 5 more hp.

It is said that the vacuum in the system helps the rings seal a little better. i cannot see any other way you will make more hp on an engine dyno. not 60hp more. 60hp is a ridiculous amount of hp. Rings are designed so that when combustion occurs, combustion gasses are pushed behind the rings to push them outwards to help sealing. im not 100% certain on the mount of vacuum we could run in a 944 engine(maybe Dave can fill us in on that) but i cant see the benefit being more then a few 1-2% more power.

As i have stated the stock pump requires just below 5 hp to drive. with all things being equal. a first stage of the dry sump system with negate that 5 hp. in fact for every stage Dry sup system you run it would cost you more hp to drive it. i can work that out dependant on the amount of pressure and flow each stage will run.

JET951

thats a very impressive engine. Am i right seeing a stock down pipe and modified stock crossover?

evil 944t

Sean,

I don't care to get into it because there are other vendors that already bought my stuff and copied it and I'd rather not help them along. I'm not sure why your in total dis belief but trust me, the numbers are solid and I have seen this in multiple engines. El Gigantic has a dyno chart for his 38-40rwhp gain. I can perhaps get a few more but, it is the truth, not some bench racing RL crap.

Also, I believe the crossover is modded as it is a Garrett GT series turbo. I know, hard to believe these GT series turbos can perform this well ... just kidding!!

JET951

Dave,
Im not asking you to give away your magic powder. im saying i cannot see how its possible. you can hold onto your secrets, Im sure if your making 60Fhp just by going dry sump then you should be getting a call from Daniel Horner from RBR.
I guess im in total dis belief because there is absolutly no proof in the thread or any other. you said you have 1 engine where you swapped from wet to dry sump so thats one comparison, now you have a few?
No one on here has even tried to explain to me where the 60hp is coming from?

I see that crossover is for a T4 housing. I actually thought it was a turbonetics turbo on that engine. Im sure its got a Turbonetics front housing and one of their anodised compressor housing backing plates.

JET951

Hi Thom,
here is a 944 sump filled with water. filled with 6.5ltrs. shows that the crank does not come close
Dont forget when its running the sump level is even lower as oil is forced through the system, not to mention the oil cooler.

Sean

Thom

Thanks Sean. I wasn't aware the level would be so low.

evil 944t

[QUOTE=JET951;8566660]Dave,
Im not asking you to give away your magic powder. im saying i cannot see how its possible. you can hold onto your secrets, Im sure if your making 60Fhp just by going dry sump then you should be getting a call from Daniel Horner from RBR.
I guess im in total dis belief because there is absolutly no proof in the thread or any other. you said you have 1 engine where you swapped from wet to dry sump so thats one comparison, now you have a few?
No one on here has even tried to explain to me where the 60hp is coming from?
QUOTE]

lol, maybe he should call me. Seems they can't get your mates KERS system to work like Vettels.

To clear up your quote, I said I personally only have one true back to back test. I have other engines with the same similar results BUT, they were not dynoed by me and I was just getting feed back from the owners. So, take that for what it is worth but again, the results seem to be within 10-15% of each other.

As for proof, I will have to ask if I can post a chart because it is not my personal car and it is a well know track car in the Upper and lower midwest PCA. Perhaps EL Gigantic will post his chart.

Chris White

The answer to one of the questions is ring flutter. It is true that the pressure behind the rings is supposed to aid in sealing but when the piston gets to TDC and changes direction the rings can unseat and unseal (allowing combustion pressure to bypass the ring seal from behind) briefly due to the high loading from the change in direction. The crank case vacuum helps to keep the rings in place and sealed.

As for the oil level issue – keep in mind that you have a crank spinning at 6k rpm that is very close to the oil level, that creates a lot of windage. Add to that the fact that the pistons are displacing a lot of air internally – the full volume of each cylinder has to be displaced every time the piston goes up and down – and the only place to move that air is to the neighboring cylinder. The only path (in a 2.5 based block) is below the crank girdle. To but that in perspective the engine has to move the equivalent of 2/3 of a liter (about 2 soda cans) of air from cylinder 1 to 2 and 3 to 4 approximate 200 times per second.

Add to that the amount of oil that is being shed by the crank past the bearings (it has to go somewhere!) and you have an ‘oil typhoon’ in your crankcase. A dry sump system will greatly reduce the oil level allowing more air space for the movement of air and the partial vacuum will make movement of the air a lot easier – a partial vacuum will lower the air density and therefor its mass.

At 6k rpm a power increase of 50hp would not surprise me…..plus the engine can be reved higher and the bearings will last. My dry sumped 3.1 liter made over 590hp at one bar of boost on its first session!

Dry sumps are definitely the way to go…as long as you have the budget for them!

Lanny Curlett

That turbo is now on my engine. I bought it from Lee Palmiter this winter. I just posted the dyno chart today.

JET951

Thanks for jumping on Chris. thats a very interesting post. of which i agree with most of it in beneficial terms.

As far as power is concerned this is what i see. for example we take into account a 600hp 944 turbo engine in which we claim we have made 60 flywheel hp gain through dry sumping. we now conclude that we had gained 4.667hp through the removal of the original oil pump, but we loose 14.001 because we have to drive the 3 stage dry sump system. so that gives us a total of 9.334hp loss. to to get our final 60hp gain we need to make 69.334hp.

69.334 is 11.5% more power. divide that by each cylinder and we see that each cylinder must make 2.8% more power. We are assuming that our extra power is coming from better sealing of the rings.

Now this is what i find interesting. I cant find the exact pressure of the combustion chamber just after ignition. i have found one for a Ford 1.4ltr at 1400rpm though. combustion pressure reaches 60bar(882psi).im very certain that a 600hp 944 turbo combustion pressure would be more. Chris maybe you can help me with this

So working backwards if we were to remove a dry sump system that means there was 2.8% more combustion gasses per cylinder going into the crankcase which would be about 24.6psi of pressure in the crankcase per piston. im not sure the crankcase could handle that and thats why i doubt it.

Of course i could be wrong here so jump in and correct where you see fit.

Sean

JET951

Ok, so after a little research i have found that a lot of high end track and drag 4-6 cylinder turbos down here in australia(such as 200Sx, 180sx,Skylines ect) run at a maximum of around 6 psi of crankcase pressure at maximum boost of around 22-24 psi. which is more then what we would be running on a 600hp 944 turbo, such as the milledge engine. As such i have worked backwards to show what hp percentage a dry sump system could achieve by sealing the rings at a better percentage.

6psi of crankcase pressure per piston is the equivalent of 0.71875% of 882psi of combustion pressure.
0.71875% x 4 cylinders =2.875%. this means there is 2.875% more sealing available if a dry sump was fitted.
So with the dry sump fitted and working we should see an increase of: 600hp divide by 100 x 2.875=
17.25 extra Hp at the flywheel.

But dont forget we have to minus 9.334hp to drive the 3 stage pump we end up with a total power gain of 7.916 flywheel horse power
Sean

elargentino

I don't really know why you are laboring so much over this?
There are proven numbers on a 944 engine many times over.

It's really a non-issue.
Have you used and tested a dry sump on a 944, or are you doing math problems?
I can personally tell you what changes when you place a 3 gallon tank out back with a -16 feed and -12 up close - and these differences pale in comparison to a wet sump.

Also - you are posting cylinder pressure numbers in the 800 range.
We're gonna be closer to a ton on these, my, those engines.

JET951

I thought this was a technical forum. im not in the business of taking advice or reporting to this forum on what i have seen without proof. hence the reason why we are here. so far no proof back to back tests. You may know of results where the dry sump system gained heaps of Hp by no one has seen it? You just cant come onto a forum and say i have 60 more hp(which is a lot) without proof or evidence.

Thanks for the info on cylinder pressure. i could not find any actual data on high hp 944 turbo max cylinder pressure. Actually a higher cylinder pressure would have even more blow by then my reported 24psi per cylinder. That makes me doubt it even more.
Sean

Thom

Sean, don't forget that US HP may be smaller than ROW HP..