Jump to content
HybridZ
Kevkev5162

Cpl 4bbl ?s

Recommended Posts

Hey all, fist post on this site, hoping for a little advice on my conversion. Mind is made up so no debate about fuel mixture etcetc necessary. I'm gutting efi on my 77 280z and going to Holley 4bbl 390cfm. I found and purchased Bob sharp racing holley intake manifold. Carb is being ordered next week. The biggest question I have is the fuel delivery. The car has a brand new aftermarket pump for efi, high pressure of course, can I keep this pump and add a bypass style fpr w gauge under hood or do I need to buy a carb low pressure pump and a bypass fpr. I'd hate to not be able to use a brand new pump. Also, any info on the Bob sharp intake, from what I see they have been out of production for a long time and perform well. I pd 200$ for it, 120$ less than a new arizonazcar one. Thanks

Share this post


Link to post
Share on other sites

Welcome man, lots of good info in the archives here also a lot of personal feelings and opinions some from some of the great guys with tons of experience and then you have the "experts" with little behind them haha so go good luck. I'm running the bob sharp setup with an MSD atomic EFI setup and it seems pretty good from my perspective. The pump will probably be an issue and you'd probably be better off getting one made for carbs instead of trying the it with a regulator and worrying with all that goes along with that. It's been done plenty of times but I'd avoid it if it was mine. Put up some pics so we can check out your ride!

Share this post


Link to post
Share on other sites

Sorry to say but it's highly not recommended...carbs operate around 5-7 psi. Having a pump feed it (even to a return style regulator) just won't work right..in theory it could but the regulator was built for low pressure and I don't think a high pressure you can turn down past 10psi. Only thing I can think of is if you go with the tbi efi conversion carb that's out there but that's a $2000 system and lowest cfm is 600 last I saw.

 

If you really want to build a reliable system the pump and regulator is going to have to be replaced. Sorry man hate giving bad news but also don't want to see ya have to throw more money because something failed. Good luck to ya and of course feel free to ask any other questions!

Share this post


Link to post
Share on other sites

I ordered an adjustable regulator advertised from 0 to 60psi w a gauge port, everything else has been ordered except that pump so I'll add it to the list and be sure to install before trying to run anything, hate to destroy the carb first shot. Update on the carb search is one was located on eBay, new in box from someone that purchased for project and decided to rebuild their Weber. Best offer of 350$ shipping included was accepted and its on its way. Only items left now are throttle cable kit, air cleaner and carb Elec fuel pump. All pics are on my phone that died last week, I'll try to pull a few from my fb page and if that doesn't work I'll take some when I get home from work. Also located appliance mesh 14" wheels locally for 100$ to replace the weld racing rims the po had drilled out from 4.25 to 4.5 to make fit

Share this post


Link to post
Share on other sites

The story is the that the po had several cars in various stages of restoration included a pair of 280zs. No progress had been made on any of them in the 2 years I knew him. We made the deal that if I finished his red z I could have the blue one along with whatever parts he had in storage. The red on needed bumpers installed, trim stuff, windshield installed and an efi relay. So for a cpl weeks of after work and weekends putting the red one together and a lot of digging thru various storage areas I got the blue one and a lot of parts including the Toyota 4x4 front brake and 240sx rear brake upgrade and bigger master cylinder

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×