dimented24x7

iTrader: (2)

I need a better spring for my regulator. My holley came with the standard spring thats also offered through TDS. Only provides up to around 18 PSI. Couldnt find any anywhere, or even a generic one that will work. Anyone still cary better springs? I need around 25-30 PSI.

BronYrAur

iTrader: (1)

I called TDS a couple months back and he had a takeout spring from the VAFPR setup, I was able to get 25psi out of it. I think I can get a little more. IIRC I was able to get about 22psi out of my stock spring by cutting a few coils off and shimming it with a quarter. I admit, though, I didn't like using a quarter in there, moved around and just didn't sit well with me. I was looking around on mcmaster carr's website a while back and they have a spring very similar to our FPR springs, pretty much the same size, you might want to look into that.

dimented24x7

iTrader: (2)

McMaster does have springs, and some are close, but theyd require cutting, shaping, and grinding to close them so they sit flush in the regulator. I was sort of hoping someone carried something prefabbed that would fit. Ill probably end up having to fab something, though.

Dewey316

I have an older TDS spring (i think I have apre laying around). I am at 22psi now, and I still have some adjustment room left (the tab is about half-way right now).

I don't know if this is the same spring that TDS still sells, but I bet it would hit 25psi.

BronYrAur

iTrader: (1)

They have some springs with ends that are already closed and ground. This one looks to be the right length and rate that it might get you good pressure: 9657K18 Look that up, you'll see it matches the size pretty well and should be good for upper 20's psi I would think.

dimented24x7

iTrader: (2)

For the spring to safely give me 28-30 PSI, Im going to need to hit 50+ lbs. of spring force. The current one hits about 25 lbs when compressed fully. Thats one of the reasons Im having such a hard time finding one is that it has to both conform to the regulator's dimensions and give the correct spring rate and force.

dimented24x7

iTrader: (2)

9657K254 looks to be the best. Its made of music wire, so itll have alot of sproing as well so there will be finer control over the fuel pressure. This has the same dimensions as the K18, but is made of a different material. That one appears to be standard spring steel. It would probably work, but it may sag if its overcompressed.

Edit: Ordered a batch. In theory, these should be made out of the same stuff that the stock springs are made of, so it should work, in theory... Hopefully it does, because holley has discontinued a lot of their TBI stuff, including the larger spring. I wonder if the late model GM spring is still available?

dimented24x7

iTrader: (2)

The regulator design in the TBIs will allow the pressure to suddenly dead head if the regulator is pressed down too far. I found that out the hard way when I dead headed my walbro. Lol, pressure shot up so fast it stripped the gears in the fuel pressure gauge. Can you see how close it is to coil bind just out of curiosity?

Dewey316

I might be able to pull it off this weekend, it really isn't adjusted that far up, i have a lot of adjustment right, not sure how close the coils would get if i adjusted it any further.

Fast355

iTrader: (2)

GM still sells the complete 28-32 PSI big block regulator assembly.

It is GM P# 17113079, $64.74 gmpartsdirect.com.

dimented24x7

iTrader: (2)

Its cool that its still available... It would probably cost around $80 by the time its said and done from those guys.

Im going to try the piano wire springs from McMaster first and see if those work. If they do, it would be a cheap, easy solution.

Ronny

iTrader: (1)

two thoughts.

i may have a extra spring spring out of my GM 7.4L TBI. not sure if it will do 50 lbs? shimmed?

consider an TBI aeromotive spring? it comes with two springs. the larger of the two 20-60 lbs. i can measure for you? i believe it is narrower and longer?if it fits GM maybe you can buy just it from aeromotive?

vinceanity92

shim the springs with washers, thats how its done on cessnas with oil pressure and fuel

dimented24x7

iTrader: (2)

Ive thought of shimming it. Its not quite to coil bind when the regulator is fully depressed. Doing some basic calculations, though, it doesnt even look like the spring is actually regulating the pressure. With the regulator at its full travel distance, the spring only provides 16 lbs at the seat. Enough for around 14 PSI. I think the pressure was just being regulated by restricting the return port. I remember that after 16 PSI, it seemed to get a little screwy.

Ronny, do you have any pics of the aeromotive springs? The OD of the stock spring is around 15/16". The main issue is that the thing has to be made of piano wire in order to provide enough adjustability and travel to work. It doesnt seem like there is much of a selection.

Ronny

iTrader: (1)

i can mike the Aeromotive 0-20 that i am not using. and give you specs. i will try to remember tonight and post tomorrow.

dimented24x7

iTrader: (2)

I got the springs. Theyre a smaller dia. then the stock ones, so theyre loose in teh bottom seat. Dont know if it will cause any potential issues. The only one they have thats teh right size, or about the right size, is teh 9657K101. Good replacement for the crappy stock GM spring, but not quite enough to go over 20 PSI.

BronYrAur

iTrader: (1)

yeah I saw that K101 spring too, didn't seem strong enough. I wouldn't think you'd have much of a problem with the spring being a little bit smaller diameter. Let us know how it works out and what kind of pressure you can get out of it. Otherwise, if it doesn't work, I would say just try to find a VAFPR or a BBC unit, they have stiffer springs.

dimented24x7

iTrader: (2)

I modded the spring to get it to the right design length, closed and ground it, and tried it on a scale. I should be able to achieve around 22-30 PSI with it. Should be interesting to see how close it is in reality. I f'd my holley TBI base up real bad after trying to remove a broken vacuum hose nipple, so I have to wait for a replacement base to arrive before I can actually try it. I dont know what the hell they make those out of, but its harder then any drill bit or tool you can buy, and impossible to remove by any known means.

liquidh8

Dimented, let me know how you make out. I am in the same boat, I posted a request for a stiffer spring some months ago. I have the BBC spring, cranked down, with the BBC VAFPR, and on have 24 PSI max. I was hoping to get upwards of 30. I have some future plans that call for boost. I am also running the n2o off the same pump, so I wanted the FP to be there. Again, let us know how it turns out for you.

dimented24x7

iTrader: (2)

I tried it. Looks like the assumptions I made when sizing the spring where just that, assumptions. Instead of around 22-30 PSI, which was my target, I have 28-38 PSI with a 2" spring. Cant complain, but its more then I wanted. I think itll work all the same, but the PWs at idle and cruise are going to be a bit low, and these injectors dont seem real linear below 1 msec. Should be enough fuel for up to around 320 grams/sec of airflow, which would easily feed around 375 HP.

liquidh8

Hmmm, I my want to try that spring out. I go from 15 at idle with the VAFPR, to 24 PSI up high at WOT, so I should be able to get 18 or so at idle, and the 28 at WOT. hmmm...

dimented24x7

iTrader: (2)

It seems to do the trick. The only weird thing is that it makes a woosh sound when the pump is running. Sort of like the sound a water faucet makes when you crack the hot water open. Sounds like someone is taking a shower under my hood. The oriface in the regulator must be vortex shedding or something.

Also, its hard to estimate the length of the spring since the spring seat floates when the regulator is operating. Youll probably have to try several different lengths untill you find one that works. Somewhere between 1.5-2" should do it. Another thing is that youll want to measure the spring seat diameter in the regulator to make sure the spring will actually fit it.

Lastly, use care when closing the spring. You need to heat the last coil you want to close up to around 1500 degrees with a torch to remove its temper so it can be worked, but you dont want to heat the adjacent coils, or the spring will be trash.

liquidh8

ok, when I make another order from mcmaster in work I'll order a few of those springs and try them out. Thanx dimented

Fast355

iTrader: (2)

Mine makes the swooshing sound as well. Never bothered me.

Ronny

iTrader: (1)

Quote: i can mike the Aeromotive 0-20 that i am not using. and give you specs. i will try to remember tonight and post tomorrow

here it is.

inside dia .73 inch... outside dia .805 inch... lenght 1.38 inch. i recall/suspect the 20-60 spring is just a thicker gauge wire so inner and outer dia changes per the increase in gauge wire.