Hey everyone. I have an 87 Trans Am that used to be a tuned port injection 305 motor. I rebuilt a 350 and took out the tpi set up and went to a carb. I have decided this year to install a twin turbo kit. I have been doing alot of research and one thing I have been having trouble researching is the fuel pump. I seen a post someone ( I forget where) That says you can wire the pump differently or something like that to push more fuel? Still I wasn't sure if that would be the way to go or if thats doable so I started looking into in-line fuel pumps and as far as having a carb'ed motor I am still unsure what would be the right pump to get/use. I know I dont think I would need something to crazy I am not running the high boost that others might use or think I will be using because I say installing twin turbos. I would like to take it to the track after getting this in, but my car is mostly a show car that I will be taking to shows on the weekends. I wanna take it to the track to see what it can do then after that I'm good. I know what its capable of. I would like to run about 8 to 10 boost or so on the turbos. As far as the in-line pumps go if you all think thats the way I should go. Do I need to run a new fuel line bigger than 3/8th? The kit has a boost reference regulator and my car has a return line so how would that return line come into play? I also plan on buying the Boost timing master from msd for the kit. Like I said though I am new to this and learning as I go. What I really been having trouble with learning about though is what direction to go in as far as delivering the fuel. Any help is greatly appreciated and thanks for your time and patience. P.S. I forgot to add that I will be doing a blow through holley 750 for the blow through carb.

 

allot of people are having luck with the walbro 255lph inline pump ,, we are currently using one on a 350 single turbo, (8-9psi) with no8 feed and return lines with a areomotive 13301 regulator

 

I see that Regulator has 3/8 in. NPT outlets and inlets. so that may work with my 3/8 in. line? Or is that 3/8 line just to small? Aslo if I used the regulator I could do away with the regulator that comes with the kit correct? Also that is a single and I am not sure if that is much different from the twin. Will I need more fuel than the single? I may go ahead and buy that pump and regulator if it will work. Then I can get back to learning about all the other stuff I need to instead of having the fuel issue in there with it. Also for that regulator did you use the high pressure spring? Thanks for the info.

 

i would probably be ok to get started with,, but don't get scotchy with the fuel system ,,,i would imagine like everyone else here, you will want more hp at some point, and making the fuel system a little bigger now, may keep you from doing it again down the road

looks like walbro has a 400 and a 450 intank pump also, i have never personally used one of these, maybe someone can chime in

 

how much hp are you looking to get ?

 

I don't wanna get scotchy with it I do wanna get it right. Thats why I am asking the questions and appreciate all the help. I think I will use that pump with that regulator with the no8 feed. What I am not clear on yet is that if I run no8 feed it will still get restricted to 3/8 in. at the regulator. Will that be ok? The pump says it will support up to 500 hp and as far as hp I don't think I wanna go that high. 400 ish maybe. I honestly dunno how much hp I will be making at 8 to 10 boost.

 

the restriction at the regulator , must be minimal (unless someone knows something i don't) many guys use that regulator with out problems

http://en.wikipedia.org/wiki/AN_thread

a link to how AN sizes work, maybe you already know

 

ok so I think I will get me one of these hoses http://www.summitracing.com/parts/sum-230820/overview/ Ran from the tank to the fuel pump then to the regulator then to the carb. Now as far as the regulator do I use the low pressure spring (from 3-20 psi) or high pressure spring (20-65 psi.) for the Carb'ed application? I also have to get rid of that fuel pump in the tank and hook me up a pickup. I found the thread for that on www.z28.com . Thanks for the help M&M I think I am getting someone where now on the fuel side of things. I am also assuming I wont be needing the supplied regulator that comes with the turbo kit since I will be running this boost reference one.

 

O.k. well I got back into looking at the fuel again lol. I did find this and wondered if anyone used it/uses it. http://aeromotiveinc.com/tech-help/frequently-asked-questions/faq-340-stealth-fuel-pumps/

It looks like it will replace the stock pump in the tank.

What do you guys think if I did the stuff it recommends for my carb'ed set up if it would be ok for me. Here are some of the stuff I would plan to do for the fuel.

• An appropriate fuel line size equivalent to AN-08 is installed
• A high-flow filter such as Aeromotive 12301 is installed
• Boost is limited to 20 PSI (allowing a 1:1 boost reference to 60 PSI max under load)
• For carbureted engines, with optimized fuel system components including a Aeromotive P/N 13204 Carbureted bypass regulator and AN-08 or ½' return line, it would be safe to allow for 900 HP forced induction (blow-through) and 1,100 HP naturally aspirated limit

So if I did those Mods whats your opinion on the set up?

 

Can you use a vacuum advance distributor on a turbo system? I have a BTM and a 6AL, but my distributor is brand new and dont want to waste money if I dont need to.

 

sure it will,, u may want to not use the vacuum till you get some tuning done,, id just un-hook it for now

 

By unhooking it you mean to just leave the Vacuum off the HEI ? Also I am still unclear how all of it works together. If I leave the Vacuum off of the Dizzy and get the MSD 6AL hook up along with the Boost Timing Master will the BTM still retard the timing without the vacuum hooked up? Sorry if the questions seem a little dumb lol I am just trying to figure all things out is all. Thanks for the help. Also as far as tuning. What type of tuning would need to be done on a carbed blow through set up? Settings as far as adjustments to the carb I am assuming with maybe some adjustments to how much to retard the timing per psi boost? Sorry one more question lol Once we do get it dialed in does the vacuum get hooked back up or do I just leave it off? If I hook it back up wont it be affected by the boost pressure? Or do I put some type of regulator on there or something like that? Ok that was a little more than one more question sorry lol. I did read something some where about tack welding the weights inside or something like that for the advance.

 

The HEI with vacuum advance also has mechanical advance. If you're using an electronic timing control, you really don't wanna mix the two methods, I'd recommend removing the vac canister altogether, just fab an arm to replace it, and also weld or bolt a stop on the advance mechanism. No sense welding the weights, they will no longer be needed, and if you weld them, you can no longer get the shaft out if you should need to replace the pickup coil.

 

Yeah I didnt mean to say weights I meant to weld the mechanical advance part of it all the way open as in some posts have suggested that I read. I do however also find this. (Quote
dmoss69
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Join DateMar 2004LocationNorth, South CarolinaPosts613Trader Score2 (100%)

[h=2]Re: Locking out timing on HEI[/h]

I had mine like this, but this is what I'm doing right now:

1. I got another distributor, and bought the weight kit from advance auto parts, it is a MR. Gasket weight kit for $9.00.

2. I got a MSD 6AL BTM box to retard my timming as boost comes in.

The reason that I'm going back to the weight set-up is when I advance my timming up to 36 to 38*, the engine loves it. It'll have throttle responce and hole-shot like you wouldn't believe, but when it warms up and I shut it down, the advance is too much for the car too crank, so I have to back the timming back down. When I get it to where the engine will crank, the throttle responce and out of the hole performance is sluggish.

What I plan on doing is put the loose springs in the distributor, and have the timming ramp in very quickly, say around 2000 rpms. The engine should turn up quickly to 36*at 2000rpms, and when boost comes in, the boost retard box will pull timming 1 to 3* per PSI, depending on where I have the knob adjusted to, which will depend on octane and detonation.

This will allow the engine to crank easily, and ramp my timming up to 36* fast. I'm not going to run a vacume advance at all. I tried that, and couldn't have the timming at 36* during WOT spool-up, because there was about 8* of timming advance taken out when the vacume was lost on the vacume advance diaphram. So if I set it for 36* at idle with vacume, as soon as I got on it, it would drop to 28*, and stayed there, which was fine for WOT under boost, but I lost some performance due to the low timming setting.

And Chevy's love timming!!! The 20* locked that you see on this website is for Fords! Trust me, I drove my 360 ci chevy (350 .060over) with 20* locked timming up the road to a friends house, and when I got there, my headers were glowing red (had fuel trouble too)! It ran like a pig, only building 5psi of boost. We turned the timming up 30*, and 10psi instantly around 3000rpms! Of course I didn't stay in boost but for a second, cause 30* was uncomfortable to me with 10psi on 93 octane even though it is intercooled. I figured 26* will be fine, but we'll see.

IF yall see something wrong or different opinion, lets discuss.

Moss End Quote)

I am running a sbc not a ford just fyi if that matters
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I just got an MSD 6530 digital 6AL2 for my twin turbo combo that's going together, it's already on the car and so far, I love it.

 

if using the 6al btm i would unhook the vacuum advance and still use the mechanical advance

 

Slayze,

You're supposed to set the mechanical advance with your vacuum disconnected. Hence why it wouldn't keep the 36* under high load conditions. It's ok for the vacuum to add the 8 or 10* under low load, it helps fuel economy to run 45* while CRUISING(low load), then it will drop back to 36* when you mash the throttle. Just thought you might like to know