I'm in the process of installing my TN tuner kit. Being that it is a tuner kit I'm going with upgraded fuel pump and 550cc injectors. Still up in the air with return fuel system. but with these upgrades do you still have to modify the fuel pump and fuel pump housing per TN instrutions or is there another way arond this.

I don't like the way TN does these. But if I have to I will. I've already PM some people on this but I'd like to hear other people's FACTS on this.

 

On my kit they didn't have to mod the assembly. I think they just cut the tabs off the new 255 they were putting in. Prehaps Dave or Juan can chime in, but thats the way I understand it.

EDIT* as for the rest, Greddy 440cc's, stock everything else. We are at 400 to the wheels and working on going higher.

 

Ok, yes they do that because the fuel pump is taller. But you probaly know that though.

 

what is the tuner kit lacking from the normal kit.

 

Injectors, fuel pump and some type of EMS.

 

install the walbro pump as expected, its essentially drop in other then trimming the tabs and I also modify the retaining cap that holds it in a little so that it doesnt have to be pushed on so far before it clicks into place.

aside from that, do NOT modify the canister in anyway at all other then opening up the swirl jet. that is the little yellow part on the bottom outside corner of the can. you can pop it out in a downward motion. the tiny little pinhole outlet of it that shoots fuel back into the small opening on the side of the can needs to be opened up. open up that pinhole to about .070".

you need to do that to get the factory internal return system to support the extra flow of the walbro 255, or else your fuel pressure at idle will spike high.

dont punch any holes in the side of the can or anything like that.

 

thanks for the help.

 

So do us TN owners that drilled the holes in the side if the canister have anything to worry about when we upgrade to a return system?

 

not in regards to the return system itself.

however, you have depleted the function of the factory surge can, which is not a good idea in a car with no real baffles in the tank.

you will experience issues with pump starvation and leaning out if you get too crazy in g-forces at lower tank levels. which anyone will, but you will experience these issues further up on the gas gauge needle.

 

Crap I'm about to break in for a 500+ power lol man more stuff to buy. Maybe ur new pump set up will be more cost effective since I will be replacing the whole thing anyway.

 

A new assembly cost me about $250 from nissan a few years ago when we needed one to cut open for fuel system R&D. We wont be able to come close to that on our assembly, especially not before we make the move to plastic.

 

I know just an excuse to buy stuff

 

If I went with return fuel system would this still need to take place? Thanks for the info.

 

You wouldn't need to modify the stock regulator but I'll let phunk speak on the siphon jet.

 

yea the siphon jet needs to modified no matter what if you put a walbro 255 in there.

 

phunk caqn you run a 255lph pump on a completely stock car, or will it make the motor run rough and rich?

 

you will need to modify the regulator and the siphon jet to keep fuel pressure in check. the closed loop cycle might have enough adjustment to compensate but i dont know for sure. you will get a CEL eventually if its outside the closed loop cycles range.

 

ill just hold off then on the install, until i do the ST.

 

Well thanks for the info. I'm starting to lean towards not going with the return fuel system for now. For I'll only be running stock boost. I think I'll invest my money toward an LSD being that it's only a base model. I think that would be the best bet.

Plus i'd like to take the extra amount of money and get rid of this SSV.

 

Im running 70psi on my stock fuel system with just the 255. Ill have to ask Dave if he modded the regulator and/or siphon jet. Im not real sure as I wasn't in the shop for that part (they were finishing up as I got there). My idle is still 800 rpm, and once in awhile if its really cold/and or idling after a hard drive, the car can tend to stall, but I don't think that has to do with fuel system as much as the stock ecu just reading wrong with the larger injectors and having to pull the air through all the piping.

Anyway, I would say you shouldn't have to worry about it until you want the bigger hp numbers. Just follow Phunks advice. We are working up to 450 whp and so far have had no issues with lack of fuel.