TBI pressure regulator spring question

[91dime]

Im in search of a regulator spring for the stock tbi regulator that has been made adjustable. After doing math, it would be ideal if i could get a spring in the 20-30 psi range. The guy at tbi chips states he has a spring that will do 12-40 psi in the stock regulator with a fuel pump that will support it. This sounds to good to be true when every other spring I see varies by about 5psi. If it is possible then I will buy it, but I have heard some not so great stories about him so im a bit weary. Here is the link.
http://www.ebay.com/itm/261404674535?item=261404674535&viewitem=&sspagename=ADME:X:RTQ:MOTORS:1123&vxp=mtr

[EagleMark]

I don't beleive that is TBI Chips ad, it's someone else. But reading in between the lines it sonds like there's more then one spring he mails.

What pump do you have? 20-30 is a lot of pressure for TBI when it comes to the tuning end, if I need that much pressure I usually look for bigger injectors.

I started to do some research on pumps and springs:
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?3145-TBI-Fuel-Pumps-Specifications-and-Regulator-Springs!

I have two springs, one works great with the 94-95 7.4L pump that is designed to run at 30 PSI. Adjustment range with gold spring is about 16-26 PSI. With silver spring about 27-29.5 PSI. The Silver spring is realy strong and more for the TPI and Vortec pumps that are rated much higher but have not tested them.

If you want a couple springs, a silver and gold from link above I could mail them out for $25 if you promise to do the testing and return results here with what pump your using and what the adjustment ranges is with stock regulator modded to adjustable?

Same deal for anyone who will return results? $25 shipped for both springs?

[BLG355]

I used a spring from a rear wheel cylinder inside the stock spring, I can go from 18 psi to about 30 with both the stock spring and the smaller wheel cylinder spring together. I haven't tried going over 30 but I doubt it would go much over that if at all before it would bottom out. The wheel cylinder was from a 95 K1500, I think it was like $7, that's a third of what that spring costs.


BLG

[91dime]

I have been reading about this stuff for the past few days and never found that link you posted eaglemark. But i did read your 10 page thread BLG and saw you used the wheel cylinder springs and was thinking it would be awesome if i could find the same springs you used. Iv read some places that the injectors dont like anything above 30 psi but if that were true then why would gm run that in some of the 454 trucks. Iv also read that some people have had injectors up to and past 40 psi with no problems.

My current setup is a GM crate L31 with performer RPM intake, shortie headers, full 2.5" exhaust, and ultimate tbi mods with 61lb injectors in an s10. Base HP is around 255 rwhp so it may be pushing around 280-300?? I may do a cam in the future and wanted to future proof it a bit. Im also confused about the pressure because every calculator i use comes out to a different psi. Iv used the witchhunter site and the excel spread sheets and it varies from 25-30 psi. Sorry for the long post but there is just so much information out there and half of it is wrong sad to say.. it really confused me when i opened a bin for the 7427 and saw the injectors were 61lb and i thought the 5.7s were 55lb. One last note, i was looking to use the ep381 fuel pump after reading it preforms more efficient then the ep241.

Edit: i confused tbichips.com with tbiparts.com which is where that spring is from.

[EagleMark]

The injectors for the later 7.4L were designed for that pressure. You can run high pressures it's just the tuning end is differant.. and harder.

For your HP with 61 LB injectors you mdo not need that much pressure! I'll figure it out for you and be back...

[91dime]

Thank you for your time in advance, been lurking are reading on here for the past couple years. I originally started with a 7747 then recently upgraded to the 7427 and tuning this has been much easier despite the code being 4 times the size. Im going out of town for a month coming up. When I get back, I may buy those springs from you and a ep381 pump and post up the info.

[EagleMark]

18 PSI will support 288 HP... if you really have that much...

[91dime]

I have no idea the real number. In a happy world 300 sounds nice but more realistically its probably around 280 if that. So i wouldn't think 18 psi would be to hard to tune. Would an ep381 pump still be good for me? or should i go with the ep377 and just use the gold spring?

[EagleMark]

I like the EP377, it's designed for 30 PSI, the EP 381 is designed for 60 PSI and from what I can find so far puts out less fuel in LPH. Every time I used the EP381 I've had issues with springs, regulator diaphragms and not being able to get lower pressure steady. The EP 377 with Gold spring just dials right in! Not sure why people all go to a 60 PSI pump, it must have a way stronger spring and then you get less variance in PSI from the regulator.

That's my two cents...

As far as injector pounds per hour the internet is full of wrong data and we've been trying to get accurate data for all injectors and everything etc... the 5.7L injectors are 61 LB/HR

[91dime]

Im finding that out the hard way about TBI. like i said before, ill read one thing then ill go somewhere else and people are saying the opposite. Where can i get this gold spring, or how much would you sell one for?