Rare fuel pump? Kyosan 0810 390lph @14v+43psi

[bboyalan]

A local member and I pulled his fuel pump assembly to swap in a Walbro 341 on Friday afternoon. We were expecting to see a factory Denso, but this showed up instead:

http://img.photobucket.com/albums/v230/AzNFLiPBoiPiNoY/3kGT/Hyro_92VR4/515a10f2.jpg
It was zip-tied to the assembly and was formerly a Denso with first section of the part number scratched off.

http://img.photobucket.com/albums/v230/AzNFLiPBoiPiNoY/3kGT/Hyro_92VR4/d8d44da2.jpg
Close up view.

For comparison, here is a stock Denso versus Denso Supra that I had three weeks ago:
http://img.photobucket.com/albums/v230/AzNFLiPBoiPiNoY/3kGT/8_25_10/b130c146.jpg

If my research was correct, a Denso "-0872" is a re-worked pump by Kyosan that flows substantial numbers if adequately powered.

The Silvia guys had one flow-tested for 300LPH @13V+40psi.
Ripped Off By NissanSilvia Sponsor? (http://www.nissansilvia.com/forums/index.php?showtopic=236839) <<

The Supra guys had a few words:
Fuel pump upgrade question (not fitment) (http://www.mkivsupra.net/vbb/showpost.php?p=2018084&postcount=5) <<

Lastly, Corvette Forum:
NEW, The Best in tank fuel pump, denso kyosan 390lph @ 40psi (http://forums.corvetteforum.com/c5-forced-induction-nitrous/2039175-new-the-best-in-tank-fuel-pump-denso-kyosan-390lph-40psi.html) <<

Do we truly have our hands on a sweet ass pump that outflows the Supra? :D

Regards,
~ALan

[DocWalt]

Yes, it sure looks like it. Great pumps, and relatively inexpensive. Or in that case, free :p

[mb7050]

I just ordered one to replace my walbro

[bboyalan]

Haha well shit, we should have left that damn thing installed. I wanted to play it safe and hot-wired the Walbro for our tuning session. I wonder how much this thing is worth....

[spfan]

did the kyosan have any kind of whine? i'm guessing not since you thought it had a stock pump.

[HLxDrummer]

Very interesting. Does it go in like stock or does it look like it required modification?

[MR2]

http://www.densofuelpump.com/

[akotten]

kind of like when I found out I had the HKS Cosmo pump :D

[wraith]

I just bought a kyosan pump recently but it has no numbers on the pump itself and its supposed to outflow the supra pump. I was meaning to have it flow tested but never bothered. My in-tank assembly was in crappy shape so I bought a whole new assembly and installed it before the pump arrived. I was going to put it in but I never ran out of fuel with the supra denso before it started intermittantly stalling out and finally failed altogether.

Sam

[bboyalan]

Yes, it sure looks like it. Great pumps, and relatively inexpensive. Or in that case, free :p
Speaking of which, I might be keeping this pump for my [hopefully] future VR-4. It seems so unique.


did the kyosan have any kind of whine? i'm guessing not since you thought it had a stock pump.
It supposedly ran as quiet as stock did. This could be subjective though. I wonder how it sounds with a BAP.


Very interesting. Does it go in like stock or does it look like it required modification?
That is what threw us off for a few minutes. It was installed exactly like stock, minus the zip-ties. I seriously thought it was a factory VR-4 pump until those other threads popped up.

Sam - If I understood you correctly, you stayed with the Supra instead? I know that Matt has been successfully using the Denso Supra/BAP combination on a few cars. Should I be concerned if this pump is underperforming and have it flow-tested?

This really makes you think twice about going with Walbro for the price, drop-in replacement, and noise.

[wraith]

I did not use the Supra. My Supra failed after almost a decade, and I bought the Kyosan as a replacement but also ordered a new tank assembly from Mitsu because my old one looks crappy, and the wiring looked weak. I got the assembly before the pump and had issues with the car idling and at WOT so instead of introducing new issues my replacing the stock pump with the Kyosan, I just put the assembly in with the OEM pump. However, now that I know the issues are somewhere else, I am planning on putting the Kyosan in. I also put the stock pump relay back in the socket. The socket used to get really hot with a jumper and I kept blowing relays on my re-wire, so I put it back to stock. I think the old Supra Denso was drawing too much current because it was stalling and it eventually just failed. The stocker doesn't seem to make the relay socket hot and since it works well at staged voltage, its also not re-wired.

Sam

[bboyalan]

Cool. Let me know how it works out for you. I will be keeping the Denso/Kyosan for future, personal use.

[Atrosity]

How many people say they own a Kyosan fuel pump. Just sounds cooler anyways. lol.

[MightyMouse]

I just ordered one to replace my walbro

I want to have sex with your interior...

[Tackhammer]

The 2 Kyosans i installed were not green, and didnt have any numbers scratched off so i wouldnt be too quick to assume you have one there

[Atrosity]

I want to have sex with your interior...

That is a pretty damn crazy fetish you have there buddy. :D

[bboyalan]

The 2 Kyosans i installed were not green, and didnt have any numbers scratched off so i wouldnt be too quick to assume you have one there
It is exactly as described by the Silvia board. I can easily assume that this might have been a modified pump from early on since it does not match what their site presently shows.

Reference:

Same number you have first 5 ground off xxxxx 0872 The "Denso" is fairly clear on some of the pumps... I'll probably send one out and have it flowed... BTW, I am over in the United States. Thanks for the replies....

The results are in... it's the real deal, 40psi 13V it lays out 300LPH, and at 14V 390LPH...

[Tackhammer]

Oh well thats cool then. Nice freebie

[wraith]

I know the HKS denso pump looked a little like that which was basically a modified Denso Supra

[jba3]

I've heard of these, and heard they don't have the trademark walbro whine. I'll be going with one when my build is finally assembled. They seem pretty epic, especially for the price.

[bboyalan]

I sent this pump out to be tested last week, and it arrived back this morning. At 14v, this rugged pump flows a whopping 215lph @35psi lol. Basically, this thing can support a 13G-class turbo for 12-17psi with 450cc injectors @3bar.

40psi 200lph
45psi 185lph
50psi 174lph
55psi 161lph
60psi 150lph

The relief valve opens at 80-85psi. There goes that "mystery" hah.

[mb7050]

hmm. Do you think its the kyosan pump or something else ?

[mb7050]

http://www.3sgto.org/f2/kyosan-fuel-pump-independent-bench-flow-numbers-pictures-2861-2.html
<-- independent flow bench numbers for the kyosan


Kyosan
PSI LPH
40 306.612
50 283.9
60 261.188
70 227.12
80 181.696
90 124.916

[bboyalan]

Yeah, I saw the thread on both forums. It was tested at only 0.5v higher than the numbers posted for the factory Denso on JL's site, but the difference is there. This would actually work decently with 510cc's @36-37bpsi. Realistically, it is just a "nicer" stock replacement lol.

[IPD]

so flow isn't quite up to spec with the walbro 255. that sux.

i'm really interested in the aeromotive stealth, but i've yet to see a dB comparison between it and the supra.

[J. Fast]

The biggest is it's E-85 compliance. 2, maybe three years with a Denso in Ethanol is all you get. There was a thread started on Colorado DSM about ethanol and a Chemical Engineer and Labratory Chemist from Boulder did some testing and found certain types of injectors, fuel lines, and fuel pumps were not E-85 compliant. That was one of them. It all started from Jack in the springs posting pictures of clogged injectors with black crap on them. This was years ago, but the test results are only a year old or so, so that's still pretty new.