26 psi Boost & Cosmo FUEL PUMP
 

Quick question ..is a cosmo pump enough to fuel a T51 R KAI with 2 x 850's and 2 x 1600's at 26 psi boost ??

I bought this pump from the RX7 store and now I am not sure if it will work with the above set up.

I'm saying 26 psi ..but I may never actually cross 22 psi .. looking for a worse case here.

Please advise.

No. Not only no, but hell fucking no. Don't even try it. See the post in this section about Ryan Crusers T04S dyno results. He HAD the cosmo pump, swapped it out for a very very large bosch pump, and still lost fuel pressure and maxed the pump out at 461 rwhp @ 20 psi. I don't know if that cosmo pump would have even supported the T04S @ 16 psi.

One thing I would look into is hotwiring the fuel pump. I also hang on another BB, Turbobuick.com, and I remember seeing flow tests for everyone's favorite walboro pump. The pumps flow droped off dramiticly at slightly lower voltages. IF that Bosch pump was getting maxed out, it might have been because of the voltage drop. What I was planning on doing, was running a wire from the fuel pump relay controlled by the ecm to a relay that would apply battery voltage to the FP when the ECM turned the Fp relay on. This way the FP still gets reduced voltage when crusing.
J

I second that notion. The nippon denso pump won't flow that hp rating either(supposedly good for 400rwhp). If you were to use DUAL cosmo pumps, you would be in the safe zone however:p:

HELP !!!
 

So what does it all boil down to ??

Ditch the NEW still in the box Nippon Denso pump and get something else ..or get another Nippon Denso pump and run them together ??

A friend with a T78 is running a Bosch pump that he tells me has a lot of flow ? Anyone care to guess which pump this is ? ..and will it work for me ?

When I bought this pump I was told by many that this is the baby to go with.. I was told that this Nippon Denso pump IS the Cosmo pump.

What should I do ??????

I wish someone would just say .. Buyt THIS pump ..pump "X" and run it with no worries. All the confilicting info is really getting me frustrated.

I need to feed these 2x850, 2 x 1600's ..and I gotta' get all this stuff asap !!

HELP ! ! ! !

I'm from Trinidad as you "location" thing under my name may indicate and there is this SUPRA here that I need to beat. It's not going to be easy though. I suspect he hits the breaks at the end of the 1/4 to throw everyone off because his trap speed is too low for his 1/4 mile time.

This guy ran a 11.2 @ 115 mph .. I smell a rat. Then another time he ran a 11.3 @ 117 mph ?!?! WTF !?! I'm not sure but he may be running upgraded turbos but one thing I know for sure is that he has a 100 shot of NOS. I suspect he is a 10.5 sec car ..but he doesn't run flat out unless the clock is off...guess what. he's alot faster when the clock is not running.

He's so full of himself that he will only race for $2500 a pop !

but here's the catch. .. his dad is the president of FIFA .. yup, that's the governing body for SOCCER in the WORLD ..like NBA is for B.Ball .. and I know that If I beat him, it would just be a matter of asking daddy for a few grand more to come back at me.. but what he doesn't know is that if I race him and win .. I won't do it again
:-) ..I'd leave him grinding his teeth.. begging for a 2nd run. That would totally kill him. It wouldn't be so bad it he was actually a nice guy ..but's he's such a momma' boy always dissing rotaries...

I need to teach this pistonhead a lesson. Help me out here fellas.

Re: HELP !!!
 

It's probably like the pump at http://www.precisionte.com/cgi-local...450219.3719710 . http://www.dougrippie.com sells a similar pump, as does M2.

I also have the Nipondenso pump with my HKS T51R-KAI TURBO,I was told its the same as the Stock Supra Fuel Pump?

What Pump would be the safest to get?Something "IN-TANK" preferably.

Anyone?

I've heard that the 300zx pump is the bigger of the nippon pumps. The Cosmo flows more than the Supra but not by much. I'm pretty sure that the Skyline is the biggest which should be the same as the 300z. I could be wrong......but i've read this somewhere and have been told by quite a few people.

I'm almost positive that the Skyline pump is the one you should run for single in-tank. If you go dual then you could run 2 Cosmos or Supras or whatever.

I have 2 Walbro in-tanks with 2 seperate lines ran to the front.....1 to primary.....1 to secondary. I could make as much power as my T-88 will allow with this setup IMO.

2 walbro's is what I'm doing in the near future as well...exact same fuel setup. The Skyline GT-R pump flows 190 lph vs. the FD pump which I believe flows 170 lph. I've had absolutely no experience with 300zx's(except that I know that I will never own one) so I don't know the size of the pump.

Re: HELP !!!
 

Well, it doesn't just 'boil down' to ONE thing...it's a combination of things. #1 the T51 is a pretty big turbo (and we all know the bigger the turbo, the more cfm it pushes, and the more air we push the more fuel we need). #2 26 psi is alot of boost (and we all know increased boost requires increased fuel). #3 You are being limited in the amount of fuel you can push by your stock fuel lines.

Now when you add all three together you come to the fairly safe conclusion that your cosmo pump will not support the rest of your system. Check out this page http://www.newwave.net/~flanham/wlanham/fuel/pumps.html

According to this the cosmo pump flows 28 gph at 60 psi. That should be where your fuel pressure is at, assuming about 34-36 psi base pressure and 26 psi boost from the turbo. Now go to this page http://www.maxcooper.com/rx7/how-to/...tem/calcs.html

Using Max's fuel calculator, assuming 34 psi base pressure, 26 psi boost, 850cc x 1600cc, BSFC of .60. max duty of 80% etc...It says you need a pump that flows 55 gal/hr @ 70 psi (34 psi base + 26 psi boost + 10 psi drop through restrictive stock lines).


You could run two cosmo pumps in parallel, but again...you are REALLY being limited by the stock fuel lines as to how much fuel you can push. Trying to push more fuel (with two pumps) through the same size line is just going to increase pressure and decrease flow from the pump.

The BIG (don't know the part number :( ) bosch pump is an option. Supposedly (see Ryan Cruser's T04S dyno thread) Ralph @ EXcessive says these Bosch pumps flow 120ish gph @ 70 psi. Obviously that would be plenty of fuel...but honestly I'm a little skeptical of these claims.

Also, it depends on how much money and time you have. My recommendation for the BEST SETUP to run 26 psi on a T51R would be this...weld a sump to the bottom of the tank (or run a 2L surge tank, having the cosmo pump feed the surge tank), then run -10 line to a large inline pump (Aeromotive would be my choice), -10 line to the engine bay, splitter to two -6 or -8 lines, one feeding the primary rail, one feeding the secondary rail, then each outlet of both rails feeding into an inlet to a FPR (SX or Aeromotive), then a -6 line back to the tank or surge tank.

Also, I hope you don't plan on running 26 psi ALL the time...not unless you have a C16 pump at your house :D

Thanks for the tips guys. I'll have to discuss this a little further with my shop and come up with a definite plan.

Re: Re: HELP !!!
 

Actually I've got better than that. I have a drum of Toluene !! ..so on race days, I can bump up the octane in the tank with toluene. All the race guys here use it.. it's clean burning and an easy source of octane. Cost about $200 per 55 gal drum :D

How much toulene do you have to mix with the gas to make approx. 100 octane gas? Is it still readily available at paint shops? Is it safe to run all the time? Just curious.

Most guys run about 15-20% of the tank volume. I spoke to this lab and they told me that over 25% may cause your exhaust to burn smoky and black ..haven't tried that much as yet.