The V8 Owners Forum -

ah so now you're fitting nitrous as well TC you waskally wabbit . . . stop giving me ideas you git!

I just couldnt resist- I got a brand new 10lb polished ally NOS bottle off t'internet for jus over £50 ( ) and a plate off a friend...
Not going to use much but want to chill the superheat comin out the bottom of the blower!!! (and an extra kick ) (couple of purge valves too maybe... )

i think my excuse is that i need it to help spi the turbos up . . . yeah whatever!

lol

You will not need a purge if you use a bottle heater and keep the Nitrous pressure above about 800psi as the liquid will compress the vapour in the line so you dont really get any nitrous lag off the line. I use an electric heater with bottle pressure control to make sure I have a full head of liquid up to the nitrous solenoid.

Having said that! I still purge at the start line because it looks cool as fook

mgbv8 wrote:Having said that! I still purge at the start line because it looks cool as fook

Yup!

Are there any 'in tank' pumps for carb applications? They always seem to be high pressure injection things

OK so you are looking at 4psi for the carb

And when you hit NOs you want 6 - 8 psi

Single pump near tank
Pipe to T piece
One side of T through regulator & filter to carb
Other side of T through Jag twin tank solenoid then Filter to Carb
When you hit the NOS bitton the Jag solenoid opens and allows fuel through at higher pressure

Still only 1 pump!

Could even make it easier system
Single pump near tank running at higher pressure required (I believe the Holley stuff has a built in regulator)
Pipe to T piece
One side of T through regulator onto 2nd T then filter to carb
Other side of T through Jag twin tank solenoid then to 2nd T to filter to Carb
When you hit the NOS bitton the Jag solenoid opens and allows fuel through at higher pressure

I wish I could draw the diagram and post but not that good!

Ian

Ian!
With a Wizards of Nos system, you just tell them what your available and consistent fuel pressure is. They will then advise what size jets to fit to hit your hp goal.

They will advise what you need even if you are running a gravity fed fuel supply from a motorbike tank. Try to get Holley to give the same advice. ?

I am going to get a 110gph holley fuel pump and I have a holley regulator too, and was going to set it at 5.5psi, using 8mm straight through and T into 6mm's into either side of the carb. Will this not cope ok?- I thought carbs were simply high volume low pressure!
If I really need extra pressure could I not just put a solid state facet on a seperate 6mm line to the carb? they run at about 6-8psi...

5 psi for the carb will be fine. You need to make sure that you have the right fuel and nitrous pressure to suit the jets you are using.

Got my nice shiny Holley regulator/splitter through this morning so that will be going right behind the blower (infront of the windscreen) so I can put a pressure gauge on the side of it right near the end of the line so pressure reading should be dead accurate. The holley fuel pump should easily be able to feed whatever the carb needs, and I will put a facet pump in on a seperate line for the nos- which should be able to push 8psi down the line, probably about 6 when it gets to the solenoid so will try and get info for jets to suit.

Cheers guys

Will a standard mx5 in-tank injection fuel pump be able to feed what a 75bhp nitrous shot needs?

I think I will put a fairly big swirl pot in the boot, use another standard in-tank injection pump to keep the swirl pot topped up, then use a holley pump to feed the carb, that should keep everything well fed! (plus if the std pump isnt enough I can just replace it with an uprated one which is a lot cheaper than another big low pressure pump)

Finally are no frills plastic (nylon or ptfe) hoses ok for routing through the car for the fuel and gas?

Got a bnib Holley red top for £43 so I'm happy, that should feed the engine ok- does -8 hose sound ok to go from the pump to the pressure regulator at the carb?

Will sink a no frills injection pump in the tank for the nos- or may make sense to take the feed from the swirl pot thinking about it..... just need a biggish pot!

Anyone have a fairly big ally swirl pot they want to get rid of?!?! I would make one but dont have the large diameter tube (or rolls for rolling it up!)

TC

Pump!

Just ordered a length of 1/2" ally tube for my main under car fuel line- 5 metres weighs just under 1kg! Using -8 stuff so should be the same size as the tube, as it is a low pressure system could I just push the rubber hoses on to the ends of the ally tube and hose clamp on or do I need to put compression fitting on and use proper hose tails?

The ally tube was a third the weight of steel, half the price and it should keep the fuel really cool by dissipating any heat into the air under the car- will just make sure it isn't the lowest part incase I ground out!!!

As long as the rubber hose is fuel resistant and you are using good clamps, then yes it should be ok. I've just replaced all my jubilees clips for bolted clips on the fuel lines, and replaced all the intercooler piping clips with those fancy bolted ones as well. Just to be sure!

Saying that, even on the high pressure side of my fuel lines I'm using Sytec clamps which are mini jubilee clips inside a shiney red thing. I recently saw a 640bhp skyline with standard rubber hoses/clips and that was running without issues.