hey guys hows it going? well i have read in the 2nd gen archives on how to do the t2 swap as well as having it half done in my garage. currently though i have read some things about the fuel pump/ gas tank and the fuel pressure

https://www.rx7club.com/2nd-gen-archive-72/my-na-tii-jdm-swap-635663/
https://www.rx7club.com/2nd-gen-archive-72/how-coverting-n-tii-26647/

in both noting of fuel was mentioned. and yet in the FSM the fuel pressure is different so my question being is it required to get the T2 fuel pump and tank??

 

Just use a upgraded fuel pump from Walbro, you'll override the stock FPR, but it'll be safe.

 

no, just a fuel pump is required.

 

so it does need the fuel pump ? the NA pump wont work i take it

 

No, it wont, use a walbro 255.

Spec.

 

i used a t2 fuel pump. and modified my fuel system

 

You can use the stock na pump to get it started and use that pump for low load situations. Even some, light boosting won't hurt.

The turbo car has a resistor in the fuel system that comes into play. It holds volts to the pump down to approx 9vdc during low load situations. During high load conditions, the resistor is taken out of the circuit and a full 12vdc is applied to the pump. You do not NEED that resistor/relay assy on you conversion.

Just buy a turbo pump and put it in. No fuel tank change needed. Use your na pump til you get things sorted out. As in idling and driving in a normal, non boost, low boost mode.

Both turbo and non turbo cars use approx 37psi in the fuel rails at atmospheric pressure. Both cars at idle hold approx 28-32 psi in the rail. The non turbo pump can't hold the higher pressure at a steady high boost. The rail pressure rises approx 1psi for each psi of boost. Like you'll see 49psi fuel pressure at 10psi of boost. The non turbo does not have the capacity to hold that 49psi for a long time. Something like that.

In other words, when I did my 87 conversion, I used the stock na pump for quite a while before buying a turbo pump. Just a personal experience with no problems using a na pump for a consideable length of time. Take it for what it's worth.

 

Hailers,

I've seen different posts that suggest you can upgrade the FP in advance of the swap and I've seen others that say you'll flood out or at best get the fuel mileage of a fully loaded Hummer H1 towing an M1A1 if you put the Tii walbro in with the NA engine still there.

thoughts?

 

Fuel pressure is not different. It's the pumps flow rate that is different.

NA's can't handle the TII's needs.

You can use a TII fuel pump. It will bolt right in. I would recommend a walbro as you'll most likely want one later on if you do mods.

A walbro with a full stock fuel system will generally override the stock FPR causing higher psi(I've personally seen 50psi). This is a band aid fix for making your injectors pump more fuel to support more boost(turning 550cc's into unknown cc's via more pressure).

I use a walbro pump set to factory psi with an after market regulator and use bigger injectors and rtek to control my fuel correctly.

 

^VR.
It's due to the higher fuel pressure. Instead of injecting the proper amount of fuel(injector duty cycle and fuel pressure determine your CC's of gas injected) your just spraying more through out the rpm range.

At idle you shoudl be in 28-35 psi range but if your pump 50psi then you coudl possible flood the motor and also get bad gas mileage.

I think I personally got 1mpg less with this method vs. FPR set to stock rate.

 

I have no doubts. I'd leave that stock non turbo in the car until you get the turbo swap sorted out. This way, if you have problems sorting things out, you won't have the thought in your head "I wonder if that Waldo is flooding it out" type of thought. Sort it out and then change pumps. Not before.

It'll only take you a half to one hour to change out the pump later if needed. I think sorting out the swap should come first before modifying things.

 

Appreciate the insight.

 

lol thing is have both the NA and the T2 in my garage so its alot easier to just pull the tank and pump! but thanks for the input guys!

 

I'm not quite sure why you'd change the Tank also. That's a puzzler.