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Whoa!! Dry sump? Are you talking about accusump? If not, I wanna hear more about this cuz I'm about to pull the trigger on 3qt accusump
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My progress updates and question for track minded people.
- Thread starter illwillem
- Start date
PWR is the best in the business and can make anything you want. Its not ideal to have painted rad fins as it affects the efficiency of heat transfer.
Ditch the stock fan and just go with an unshrouded spal.
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Ditch the stock fan and just go with an unshrouded spal.
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As requested, here's a pic of the PWR. 
- Joined
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No accusump is just insurance for a wet sump system. The wet sump systems rely on the oil pump thats driven by the crank to scavenge and recirculate the oil to this system. While reliable for the average commute they must be beefed up to track conditions (ie accusumps, pan baffles, billit oil gears, milled housings..) Even then, over-revving can cause the oil gear which is a well known frail backbone of the system to explode (like mine did) or cavitate and interrupt normal oiling condition.
A dry sump is basically an external oil reservoir and pump system that injects oil into the motor. A benefit is since you're no longer using a 'pick up' type system that needs to fit in the small space under the car you have much more freedom to use oil hopper designs eliminate problems like oil slosh. Also adding things like cooling and increased capacity are relatively simple. Another added benefit is no parasitic drag on the crank to spin the oil gear means you free up power. (up to 15-20 some claim)
When you look at the costs associated with upgrading a wet sump system (which anyone that tracks an NSX NEEDS to do)
OIl gear
baffled pan
oil cooler
accusump
milled oil gear housing
labor
motor rebuild if your like me.
you are in it way more than just getting a nice system made up.
There are a few good ones on the market, much pioneering had been done in the aviation sector so you know the R&D is there but I would really do my homework to make sure it fits your needs. I had heard that autowave has done a couple, I don't know if thats true but theres plenty of people around here that would have insight.
A dry sump is basically an external oil reservoir and pump system that injects oil into the motor. A benefit is since you're no longer using a 'pick up' type system that needs to fit in the small space under the car you have much more freedom to use oil hopper designs eliminate problems like oil slosh. Also adding things like cooling and increased capacity are relatively simple. Another added benefit is no parasitic drag on the crank to spin the oil gear means you free up power. (up to 15-20 some claim)
When you look at the costs associated with upgrading a wet sump system (which anyone that tracks an NSX NEEDS to do)
OIl gear
baffled pan
oil cooler
accusump
milled oil gear housing
labor
motor rebuild if your like me.
you are in it way more than just getting a nice system made up.
There are a few good ones on the market, much pioneering had been done in the aviation sector so you know the R&D is there but I would really do my homework to make sure it fits your needs. I had heard that autowave has done a couple, I don't know if thats true but theres plenty of people around here that would have insight.
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There aren't many nsx dry sumps out there and those that are lose the A/C which I do not want to sacrifice.
Thanks for the input. The rads have additional capacity so we're trying to see what we can get away with. I.e. testing with blocked/restricted airflow, various color schemes, even running on a OEM unvented hood with a front license plate, with the stock fan, 1 fan, shroud, skeleton shroud, 2 fans, full Type R undertray.. etc, etc. All options are being considered in the name of data gathering...
I have not been able to find a traditional "racing" radiator that was 100% drop in. It usually thicker like the Ron Davis 3-4" core or requires hose modifications, etc. I'm very interested to see how the PWR fits and performs. It looks very clean and tidy. How much was it? It doesn't look much thicker than stock so i'd be curious how this performs on an FI car.
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I thought I read somewhere the Corvettes are having problems with their Dry Sump. Something about degrading pressure losses. Will try to find the article tonight. I just don't know if i'd want to be a guinea pig for something as important as the oil system.
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- 29 November 2012
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- 278
Thanks for the helpful insights but looking at the list above, I may be better off going accusump route since it already has everything except accusump... plus loosing AC is big no no for me
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You could still get PWR radiators. Here is an email I received from PWR in June 2013.
--------------
Hi Daniel,
Sorry for the delay but I just retrieved your email from my junk mail. Are
you still in need of NSX radiators?
Yes, the models are available. They are manufactured at our factory in
Australia and shipped directly to you in about 3 weeks time. Shipping costs
approximately $195 for this size of radiator.
I believe that no modifications are needed to drop into your NSX. If you're
interested, I can provide drawings to you so that you can verify the fit.
PWR2971 - $750
PWR6172 - $1250
I hope this helps. Feel free to call or email with any questions.
Thanks,
Justin
Justin Raybourn||Sales Engineer/Manager||PWR USA, Inc. ||704.658.0092
o.||704.968.8976 m.||www.pwrradiators.com
I don't believe an accusump is essential unless you are on slicks and have high speed sustained parabolic turn track.I have the billet gears and baffled pan.I use Ra1. An accusump is not a trivial mod.it takes extra diligence to run and trouble shoot.It is not an install and forget mod.
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Assuming 3000 scfm fans, a conservatively small flow area of 1.5 ft^2, and a conservatively low pressure coefficient of 0.8, your fans/shroud become a restriction above ~30MPH.
But, you still need a fan when you are creeping in traffic too, or trying to cool off in the pits. In the picture above, the trimmed OEM fan/shroud is pretty much useless in that regard. Why? The OEM shroud places the fan about 1" or so away from the radiator so that it could act as an efficient collector. If you trim the sides and the fan is on, the air will take the path of least resistance... which means it will be sucked in through the trimmed shroud sides and not through the front of the radiator.
You can either buy a custom fan(s) that mount flush with the radiator, or still use the OEM fan/trimmed shroud with side modifications. I trimmed my shroud and attached aluminum side fins. Sorry for the pictures that don't show the side pieces I made very well, but here's what I have:
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The radiator I have is the 42mm thick 18fpi PWR #2419 that MJ used to sell. I think the PWR #2971 part number given above may be incorrect (according to PWR's catalog). The 2419 is a drop-in version. The PWR #6172 is the 55mm thick racing one with the integral oil cooler... I didn't like the idea of running my oil lines all the way to the front and putting more restriction and stress on the OEM oil pump when I could come up with a reasonable cooler at the rear of the car.
Like your build! I also like what you did with your horns and mounted them out of the airflow path to the radiator. I mounted dual PIAA's right above each other along that thick support in the middle to get mine out of the way too. You can see the top horn in my first picture.
Good luck with the radiator selection. I just wanted to point out not just trimming an OEM shroud if you planned on using it without covering up the sides.
Dave
Ive notices that in a few photos I see of larger rads the shroud has been trimmed down on the sides, that may be a good solution for now.
But, you still need a fan when you are creeping in traffic too, or trying to cool off in the pits. In the picture above, the trimmed OEM fan/shroud is pretty much useless in that regard. Why? The OEM shroud places the fan about 1" or so away from the radiator so that it could act as an efficient collector. If you trim the sides and the fan is on, the air will take the path of least resistance... which means it will be sucked in through the trimmed shroud sides and not through the front of the radiator.
You can either buy a custom fan(s) that mount flush with the radiator, or still use the OEM fan/trimmed shroud with side modifications. I trimmed my shroud and attached aluminum side fins. Sorry for the pictures that don't show the side pieces I made very well, but here's what I have:
The radiator I have is the 42mm thick 18fpi PWR #2419 that MJ used to sell. I think the PWR #2971 part number given above may be incorrect (according to PWR's catalog). The 2419 is a drop-in version. The PWR #6172 is the 55mm thick racing one with the integral oil cooler... I didn't like the idea of running my oil lines all the way to the front and putting more restriction and stress on the OEM oil pump when I could come up with a reasonable cooler at the rear of the car.
Like your build! I also like what you did with your horns and mounted them out of the airflow path to the radiator. I mounted dual PIAA's right above each other along that thick support in the middle to get mine out of the way too. You can see the top horn in my first picture.
Good luck with the radiator selection. I just wanted to point out not just trimming an OEM shroud if you planned on using it without covering up the sides.
Dave
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Thanks for the awesome info, i'm going too look for the right SPAL fan to get, if I cant find anything im going to do the same thing you did.
I am looking more and more into getting a larger rad. I really don't ever do more than 8 lap back to back and i've not been driving the car at the track when its been over 85* but its going to be one of those things that nag me, this is a case where more is better.
This last weekend I swapped back to my cedar ridge rear toe arms and heat shielded my oil pan from the header with some more NASA foil i had. I drove the car a 250 miles to hang out with some friends that were driving an event at Streets Of Willow. It was really nice to get back out there with the NSX even if I wasn't on track driving. It rode much better than I thought it would with the new rates and all the non compliance stuff. The ball joint replacement i think made the most difference overall in front end feel.
Unfortunately, I did get a CEL 43 from the bank fuel system on the way there, after I cleared it I got a CEL with 1 blink another two time after doing the procedure described in the FSM. As i suspected my 02's are due for a change. Its only reading the code for the front bank but im going to do both this weekend along with the fuel filter and finally replace the accusump electronic valve too. I can then finally actually do some 0 to redline pulls and see how it feels.
I am looking more and more into getting a larger rad. I really don't ever do more than 8 lap back to back and i've not been driving the car at the track when its been over 85* but its going to be one of those things that nag me, this is a case where more is better.
This last weekend I swapped back to my cedar ridge rear toe arms and heat shielded my oil pan from the header with some more NASA foil i had. I drove the car a 250 miles to hang out with some friends that were driving an event at Streets Of Willow. It was really nice to get back out there with the NSX even if I wasn't on track driving. It rode much better than I thought it would with the new rates and all the non compliance stuff. The ball joint replacement i think made the most difference overall in front end feel.
Unfortunately, I did get a CEL 43 from the bank fuel system on the way there, after I cleared it I got a CEL with 1 blink another two time after doing the procedure described in the FSM. As i suspected my 02's are due for a change. Its only reading the code for the front bank but im going to do both this weekend along with the fuel filter and finally replace the accusump electronic valve too. I can then finally actually do some 0 to redline pulls and see how it feels.
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Sorry for the thread jack-
The Corvettes namely the Z06 (LS7) and the Grandsport are not a true drysump, they are a hybrid wet/dry setup. The engine uses a traditional crank driven oil pump that is two stages in the block to feed the engine oil to the block and the oil storage tank. The oil is pumped from the shallow oil pan to the oil storage container from one of the two stages in the oil pump the other stage of the pump is feed via an oil line from the oil storage tank. The design goes a long way to help with oil slosh and to help with crank case pressures but is only about half way better than a true dry sump. So GM accomplished what they set out to do, they designed a hybrid oil system that is better than a traditional wet sump for high G driving but not nearly as good as a true dry sump with seperate pumps for each stage. In a true dry sump one of the biggest advantages is the added crank case ventalation that type of system offers.
As a side note the dual stage oil pump required a few other compromises like a single row timing chain due to space constraints of the bigger two stage pump. I have yet to take apart an LS7 that did not need a new chain and timing gear set, not to mention valve guides. My engine builder has a few tricks up his sleeve that allows for a dual row chain but it is a lot of machine work and welding on the stock block and oil pan to make it work.
Dave
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Thanks DDozier
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Who's Rad is this? PWR? It's distinctly different and configured in the more ideal side-to-side flow instead of the bottom-to-top flow the stock NSX is and every other NSX replacement rad i've seen. This is a big reason why it works with one fan and no shroud. If you were to do the one fan config with no shroud on the bottom-to-top flow radiator I just can't see it working unless you were always driving at speed and in mild rpms. I've tried different 1-fan configurations already here in LA traffic and w/o a shroud I can't see it working on my FI car (maybe NA?). It also falls flat on its face in the higher altitudes up at ACH and GMR.
Dave - Is this configuration working for you? At first I thought you had the same rad as the above SOS pic but yours is the traditional bottom-up-up flow config also. In all my testing with various setups I just can't see how this will work in street driving where I live. I had to use the OEM shroud with a modified fan as shown in a previous post here. That worked amazing but the restriction at high speed is there from the shroud, but not enough to "Overheat". With our prototype version ECT got as high as 210-220F in my car after a 15 min session at Street of Willow at an estimated 140-150F track temp. I'd still like the temps to stay closer to 200-210 which is why the improvements must continue and further tweaking to tube and fin design is needed.
illWillem - I received the prototype fans from a company Jim and I have been working with in Italy. They are an OEM supplier and they helped me balance out the CFM, amperage draw, and fitment constraints. We ended up with one of their off-the-shelf 5-blade turbine fans and a custom order slim fan with a high torque motor. My moto is not to overbuild (which is easy, costly, and wasteful) but instead to optimize which seems exponentially more difficult to pull off. The latest version of the rad we're testing now is the only rad we've come across that fits exactly like OEM and can cool a turbo charged C30A pushing 600wHP, with a Laminova oil cooler and a thick FMIC further blocking front air flow. I'd love to try a PWR though. Like I've said.. they make nice stuff but aluminum has it's limitations so it makes really curious.
I can't remember if you still have your ABS system. If you do you might want to consider a fan setup like this. It's the only way it's all going to fit. If you're running a thick Ron Davis or any thicker than OEM radiator AND still keeping the OEM early ABS setup I just don't see two fans fitting at all.
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Who's Rad is this? PWR? It's distinctly different and configured in the more ideal side-to-side flow instead of the bottom-to-top flow the stock NSX is and every other NSX replacement rad i've seen. This is a big reason why it works with one fan and no shroud. If you were to do the one fan config with no shroud on the bottom-to-top flow radiator I just can't see it working unless you were always driving at speed and in mild rpms. I've tried different 1-fan configurations already here in LA traffic and w/o a shroud I can't see it working on my FI car (maybe NA?). It also falls flat on its face in the higher altitudes up at ACH and GMR.
Dave - Is this configuration working for you? At first I thought you had the same rad as the above SOS pic but yours is the traditional bottom-up-up flow config also. In all my testing with various setups I just can't see how this will work in street driving where I live. I had to use the OEM shroud with a modified fan as shown in a previous post here. That worked amazing but the restriction at high speed is there from the shroud, but not enough to "Overheat". With our prototype version ECT got as high as 210-220F in my car after a 15 min session at Street of Willow at an estimated 140-150F track temp. I'd still like the temps to stay closer to 200-210 which is why the improvements must continue and further tweaking to tube and fin design is needed.
illWillem - I received the prototype fans from a company Jim and I have been working with in Italy. They are an OEM supplier and they helped me balance out the CFM, amperage draw, and fitment constraints. We ended up with one of their off-the-shelf 5-blade turbine fans and a custom order slim fan with a high torque motor. My moto is not to overbuild (which is easy, costly, and wasteful) but instead to optimize which seems exponentially more difficult to pull off. The latest version of the rad we're testing now is the only rad we've come across that fits exactly like OEM and can cool a turbo charged C30A pushing 600wHP, with a Laminova oil cooler and a thick FMIC further blocking front air flow. I'd love to try a PWR though. Like I've said.. they make nice stuff but aluminum has it's limitations so it makes really curious.
I can't remember if you still have your ABS system. If you do you might want to consider a fan setup like this. It's the only way it's all going to fit. If you're running a thick Ron Davis or any thicker than OEM radiator AND still keeping the OEM early ABS setup I just don't see two fans fitting at all.
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RYU - the first photo is Kip's car with Shad's custom radiator dating some years back.
I have posted a picture of my dual Spal with shroud which works quite well. A shroud will better help move the air out of the hood - here was the R&D: http://www.nsxprime.com/forum/showt...Ducts-with-Air-Vents?highlight=dual spal fans
And this is the final set up picture.
I have posted a picture of my dual Spal with shroud which works quite well. A shroud will better help move the air out of the hood - here was the R&D: http://www.nsxprime.com/forum/showt...Ducts-with-Air-Vents?highlight=dual spal fans
And this is the final set up picture.
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I pulled off my ABS a while ago but at this point om more concerned about the post radiator evacuation ducting, after doing a few designs I am happy with the slant of the ducting from bottom of the radiator to hood exit. Unfortunately ive more or less built myself into a box in regards to the size radiator and what fan im gonig to use. I still have some room to go so I can make changes, and im not going to NOT purchase something because it wont fit but at the same time im looking for soultions that wont require me to remake anything. im interested in that set up you have if youve got one around it'd be rad it we could test fit or measure it and see how close ill be.
Shad's rad is a nice design. I've pondered doing that layout but fitment issues with the crossover coolant pipe made me decided it was a last option to pursue. It's really an ideal layout though. One can run a strong single fan. Not have fitment issues with the ABS and not need to run a shroud for city driving and it won't cause air blockage at high speeds. It's just that darn crossover pipe.
I noticed in your shrouded dual fan setup you're still on the OEM radiator. I can attest that the OEM radiator is really quite an efficient piece of design. It works in almost all conditions except the most extreme from my personal experience. I have not tried your setup, though probably should have before proceeding into the abyss of radiator design i'm currently heading in.
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Wil, in all honestly i'd try a twin fan setup with no shroud on your Koyo since you've already got that rad... assuming two big fans fits in your ducting. You're still NA so your motor doesn't generate as much heat as mine. You're also a much faster driver than me so the high speeds will help LOL. The Koyo also has a less dense fin design so you will benefit from some added downforce as the air passes up thru your hood duct I reckon. Heck, if you want to really save some money you can borrow my Spal paddle fan mounted to the OEM shroud and see how that works. I can carry a few spare fans at our next track day. They're easy to swap out into a twin fan setup which is a sure thing imho. It's also starting to cool down. It's amazing how much 15deg F of cooler ambient temp helps.
Totally just my $0.02 here. As you can see a bunch of us have varying opinions and these guys are much smarter than I.
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RYU - I agree that unloess one is pushing serious rwhp, running constantly high RPMs and on high ambient temps, a clean OEM radiator should be sufficient especially with a dual fan.
Yes, Shad's radiator has that peculiar cross pipe but it is very efficient and very effective up to a certain level of rwhp which we are all under.
As for the shroud causing air blockage at high speed - well, it all depends on your shroud. Consider the OEM where the shroud covers pretty much half of the radiator. Visually, it is clear to me that the dual fan with a shroud has more open surface through the fans than the OEM! And presumably the more efficient dual Spal pull fans are sucking the air from the corners of the shroud out the duct - if high speeds is at the track, you are probably at high RPMs already and your fans are spinning already. Also, I did not have an issue with the old ABS system with this shroud.
If your OEM radiator is relatively in good shape, just give it a try with dual fan and no shroud at first and see if you find improvement in temps.
Yes, Shad's radiator has that peculiar cross pipe but it is very efficient and very effective up to a certain level of rwhp which we are all under.
As for the shroud causing air blockage at high speed - well, it all depends on your shroud. Consider the OEM where the shroud covers pretty much half of the radiator. Visually, it is clear to me that the dual fan with a shroud has more open surface through the fans than the OEM! And presumably the more efficient dual Spal pull fans are sucking the air from the corners of the shroud out the duct - if high speeds is at the track, you are probably at high RPMs already and your fans are spinning already. Also, I did not have an issue with the old ABS system with this shroud.
If your OEM radiator is relatively in good shape, just give it a try with dual fan and no shroud at first and see if you find improvement in temps.
I use 1 SPAL on both my E36 M3 and Foxbody Mustang (and will soon have one on my NSX). Keep in mind the typical 15" 2,0XX? CFM curved-bladed fans can draw up to 90AMPs at startup before they quickly stabilize at ~20A. Not sure what the stock fan draws...
William - what times are you turning in your NSX at BW, compared to your S2K?
William - what times are you turning in your NSX at BW, compared to your S2K?
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Not sure if your talking to me or another William.
Last time I drove my NSX at BW was about a year ago last summer in the heat. I did a 2:04.1 with some pretty ragged r888's and leaking slave cyl that would only hold pressure for about 3 laps at a time. I never drove my s2000 on cw13 but I run a 2:05 in my RSX on Azenis.
Last time I drove my NSX at BW was about a year ago last summer in the heat. I did a 2:04.1 with some pretty ragged r888's and leaking slave cyl that would only hold pressure for about 3 laps at a time. I never drove my s2000 on cw13 but I run a 2:05 in my RSX on Azenis.
To you. Be sure to post what you do with your new setup. What about your NSX vs S2K SOW times?
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Figuring out the new set up now, i smashed my hand and its been in a slow recovery so i havent been able to do anything to the car for the past few weekends, bummer.
I do a 1:22 CCW at streets and a 1:23 CW at streets in the NSX on NT01's. I think the s2k was a 1:27 both ways on rt615K, never had real tires or areo on it. I think maybe now I would be able to go faster on the same set up- zeals coilovers, 22mm front sway, 17x9 square set up.
I do a 1:22 CCW at streets and a 1:23 CW at streets in the NSX on NT01's. I think the s2k was a 1:27 both ways on rt615K, never had real tires or areo on it. I think maybe now I would be able to go faster on the same set up- zeals coilovers, 22mm front sway, 17x9 square set up.
Could someone tell me if the fan runs when you are at high speed? I thought a the track while racing the fan is not running?
Sorry, for the ot Wil just really excited about completing the last round of testing. The latest designed kept temps on Jim's car at 205f when the bigger Ron Davis rad would get up to 220f. The fin design coupled with the metallurgy works. I just need to try it on the oem fan on my car. It works amazing on two Spals (no shroud). Now to convince the manufacturer to do a production run specifically for the nsx. The volume projections just aren't there... Might be able to do a one time group buy hopefully. Stay tuned...
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