just finished turbo swap!

[blackedoutz]

i just got my 77 280 back on the road, well it running, sounds amazing, now i just have to figure out how to make it go fast, without blowing anything up, my setup (as of now)

stock 81 block, 300cc injectors, t3t4 turbo, 38mm tial wg set to 13psi, fp from the chev ss turck, adj fpr, ic with 2in pipes, bov,

for some reasone i cant get my fuel pressure past 25psi without bogging the motor out? and i am thinkin 25psi is not going to cut it for 13psi of boost. my question is what would be causing me to run so ritch at 25psi at the injectors? being since stock is around 35psi?? any advice would be great

[NISMO619]

Your FPR have u tried to use your stock 280zx FPR ? mine reads fine all the way up to 40 plus. i think the highest ive seen it was 42 psi

[cygnusx1]

What are you using for electronics? Stock EFI?

 

If so, with the 300 injectors, you definitely need to adjust that AFM wheel leaner. Set the AFM leaner by tightening the spring, get it to idle and rev well with about 35-40psi fuel. You might get a really rich spot around 4000-4500 rpms under load but with the factory FI, that's the deal. You might want to consider and FMU or a standalone EFI system.

 

PS: My FMU is for sale.

[blackedoutz]

stock efi, i put the stock fpr back on, just to see if it was my fpr actin up, same prob, i will try adj the spring in the afm to see if that solves the prob. thanks for the help!

[Tony D]

It WILL act up with the stock FPR in there, there is too much fuel with the 300cc injectors, about 25% too much. Either lower your fuel pressure 25% (not a good idea) or do the AFM Rig to lean it out while on the flapper.

 

Problem with the Bosch System is you are better off keeping stock injectors and playing with a Rising Rate Fuel Pressure Regulator than you are installing bigger injectors. With stock injectors, off-boost drivability remians as stock, and under boost additional fueling is taken care of by raised fuel pressure.

 

I'd get Megasquirt ordered now, and just start reading on how to tune it. You will be better off in the long run!

 

With 300CC injectors you will be in the area of 75-80 psi requirement at 13psi of boost. If they were stock 280ZX injectors you would be in the range of 100psi and about maxed out.

 

Hope you got a good fuel pump! You didn't mention it, and if it's a stocker, you will stangnate the fuel flow at around 60psi when the internal relief valve lifts---then you run lean and go 'boom'!

[blackedoutz]

ok i tightined the spring in the afm and got my fuel pressure up around 50psi but i think i am still runing lean, doesnt feel like it is pulling as hard as it should with 13psi of boost, and i cant really tell if i am detonating cause it gets a little noisy with an open down pipe. Tony, i did mention i had a fuel pump from a supercharged v8, and i am runing it staight of the alt. (with a relay of course). so i should be ok there

[cygnusx1]

It is going to take some experimentation and some luck to get it not too lean in some areas and not to rich in other areas. If you don't want to get a standalone, you will need an FMU or RRFPR to get it closer to correct.

 

I ran my stock (270cc) injectors from Factory-psi@idle to 65psi@15boost. It made excellent power and ran great.

[blackedoutz]

so just how tight can you tighten up the spring on the afm without breaking it???

[cygnusx1]

If you tighten it enough to break it, the car wont run and you are doing something wrong. You probably need to tighten it less than a full turn MAXIMUM. I tighten it carefully with the engine at idle and get it to idle as smooth as possible. Set the idle air screw to center before you try this. Then you can use the idle air screw to fine tune it.

[HoustonZ]

HAHA!!

 

Was that you in the Dillards parking lot yesterday afternoon?