after advice on a blow thru turbo setup
 

just wondering if u's can give me some advice on a carby fed turbo setup. its not commonly done here in australia as the price of 13bt's and all the injection computers is cheap as, i already have an turbo'd and injected 1st gen, but i want something different.
basically i just want a budget setup for another car that ive put a rotor into that will pull the numbers but will be cheap to build. ive seen the vid of directfreaks car running with the 600 holley, and it goes well, but i was wondering what else spesifically needs to be done to the carby to allow for a blow thru setup?
basically its a standard 12a, i have both a stock carb and an adaptor for a holley, but im not sure which would be best to use cause i did a search and theres a lot of varying opinions.
the gear i already have is:
s4 turbo
exhaust manifold
oil lines
dump pipe

do you have to fill the float in the carby with something so that it doesnt crush under pressure? what sort of jetting needs to be done?
my main concern is with what carby to use and what needs to be done to it.
i will be running a front mount intercooler and blow off valve as well.
i should note that have done a similar thing to another car i owned but i could never get it to run right due to tuning the carby and jet sizes, so any advice would be GREATLY APPRECIATED.

thanks
justin

Try PM`ing Robert (680RWHP) or Sterling, they are the gurus in that subject. Robert also sells turbo hats and prepped carb kits at his store www.rotaryshack.com

neh

cheers ill give em a pm

anyone else

There's more information than you could possibly need here if you do a quick search.

i tried that but i couldnt find anything that i was specifically looking for, some people say use a nikki carb, others a holley. i might go for the holley i rekon, now what size do i need? what further mods does it need?

holley has plastic non crush floats available. only one that can turbo prep a nikki carb at the moment is Robert at rotaryshack.com. you have to use email to contact him. No pm's in his direction. only carb that i know of that you need to fill the float on is a weber ida which is what i use for my set up. (pics in sig) but I have a special polyurethane float from japan.

did you try searching turbo nikki. they are not just trying to put you off there is an ungodly amount of post on this and the search function will bring them up for you. try the advanced search. limit the area and add a couple words that you might use if you were making a post. try not to leave it really broad cause you will get about 50 pages of useless info.

anyone with carb knowledge can boost prep a carb. most carbs shouldnt have to many places to leak or they wouldnt work very well.

sterling and carl boost prep nikki carbs

webber 50mm carb is what i used. it worked great and made about 250WHP
on a stock turbo with a 60 compressor upgrade.

If you have easy and cheap access to EFI - then DO IT.

did they work out there problems they had on the prototype? Havent heard otherwise. sterling and carl not knocking you just havent heard that you have been successfull with the boosted nikki.

i just dont want to, plain and simple. i already have my rx7 efi turbo and it goes well and all, but i really wanna just turbo it with the parts i have lying around to keep the costs down.
that clip of your car, when u were racing the 350z, were you running a carby then? looks like it moved alright. love the gauges :cool:

thanks for the info everyone, ive found out heaps, i will be going for the holley, the only problem it that no one here deals with holleys on rotors, its all webbers and efi. a mate just put a holley on his 12a bridgey and hes having heaps and heaps of trouble finding someone who can do a decent tune on it. i think im gonna resort to a lot of trial and error.

is a 600 too big?

boost prep your nikki. easy as pie.

I was (and still am) running a Holley 650.

I can help point you in the right direction as far as the air bleeds and the jets, but the rest of the boost prepping was done by a rotary friend of mine.

Prepping a holley basics:

Must:
-Brass floats need to be replaced w/ nitrophyl floats (won't crush under boost)
-Mill off choke horn and seal choke lever hole. (prevent boost leak)
-File the mating surfaces to the metering blocks on both the main body and the metering blocks to make them more true/flat. Holley machining isn't very precise. (prevent boost leaks)
-Jet up, start by going 10-15 jets up on both pri and secondary (for safety) and jet down from there to a comfortable a/f ratio.


Optional:
-PVCR's (Power valve channel restrictions) drilled slighty larger. (better off bost drivability)
-Larger needle and seat (for higher power applications)
-proform main body (replaces holley main body, already has no provision for choke, perfect milling so no need to file, and you get removable air bleeds for more tunability, best 90 bucks i've ever spent)

Thats about it, might have missed a couple odds and ends, go ahead and ask any more questions if you need to.

-Marques

*subscribing*....

Doing this within the next couple months...

Dan

thanks for that, thats sensational, just what i was after.

thanks everyone, i think i got more than enough info now. now to go and get a holley.

thanks again.