Im starting to get my stock 91 camaro rs ready to drop an Lt-1 in hopefully sometime this next year. One of the many steps is that i need to install a better electric fuel pump in order to feed gas properly to the Lt-1. I know that the Walbro 225 electric fuel pump is often used for this type of upgrade. My question is if I install this new fuel pump into my car will my current stock 305 V8 be able to handle the increased pressure... what I mean is will this new fuel pump cause my car not to run properly. I would like to do someo the smaller stuff before i drop the engine in but I still want to be able to drive my car uptil the engine swap finally happens.

Thanks

 

I am assuming your running TPI. If so, you will be fine. The extra volume of gas will be routed back to the tank via the return line.

Just make sure your fuel pressure regulator is in good shape.

 

Just to be sure, I would measure your fuel pressure now, before the fuel pump change. And when you make the fuel pump upgrade, also install an AFPR. After the fuel pump install, and you get things running again, set the fuel pressure to where it was before the fuel pump upgrade. I recently had a 255 Walbro fuel pump installed into my '87. I got an increase of 3 to 4 psi more fuel pump, so I simply turned the fuel pressure back to where it was before the pump install.

 

Okay this might sound dumb but whats a "AFPR".. and is it difficult to install?

 

im assuming it means automatic fuel pressure regulator

 

It would be Adjustable Fuel Pressure Regulator. Allows you to go and fine tune the fuel pressure. I didn't see it mentioned, but do you have TBI or TPI on your engine now? Installation of the part will vary depending on your current setup (although its not too hard on either).

 

He has an RS - so in theory it's a TBI, not TPI.

 

Im pretty certain I have a TBI.

 

Ok, Ive taken a change in direction with my car. I was going to do an Lt1 swap but now Im looking into having a custom carbed 350 built. Mainly because with this build it willhave more horse power and be alot simpler. But my question still remains with swaping to an carbed 350 do I ned to upgrade my fuel pump, I know with the Lt1 swap it was suggested to me that I swap to a waslbro electric pump...But I dont know if I need to do the same with a carbed engine....Any suggestions or advice?

 

Probably not - kinda depends on how mean the 350 is I guess. My stock fuel pump runs my 350 fine, but it's no 800hp monster.

You will need a return style fuel pressure regulator like the Mallory 4309, along with the right TV cable geometry correctors for your carb, a good sturdy throttle bracket, a method of locking the torque converter, and an HEI vacuum advance distributor.

Did we ever determine if you have TBI or not? Do you have what looks like a carb with two fuel injectors mounted inside?

 

I have tbi, and about how much does a regulator cost.

 

This is the one I mentioned: http://www.summitracing.com/parts/MAA-4309/

All of the return-style are pretty pricey - but necessary. Since we have a return-style fuel system, we have to use a return-style regulator - it works by using what fuel it needs to get the correct pressure, and returning the unused fuel back to the tank. Many folks try a standard cheap dead-head style regulator, some work, most don't. The TBI pump makes too much pressure to just dead-head it.