bcty

1.Someone explain how this whole riseing fuel pressure regulator work.. i know when it senses boost it ups fuel pressure.. but is itself the fuel pressure riser/regulator or just the part the senses it?

example : i have a fuel regulator in my car now tuned to 6psi.. best for holley.. anyways i was wondering if the thing i have to buy now i set the min fuel pressure rate on that and then hook it up to a vaccume signal? and send fuel through this device to get regulated? or does it go though a another regulator and that regulator is controlled by the vaccume line by this riseing fuel pressure regulator..

2.Is it mounted closest to the carb better?

3.Is the BOV just mounted anywhere in the intake track or is it better closer to the turbo or carb?

4.So what do u use for a fuel pressure regulator? i guess i need to send it a vaccume signal..

5.And if i want to run 20psi (for example) i should be looking for a fuel pump that does 26psi right? my car does 6psi at idel, so 1psi more fuel per 1psi of boost right?

6.Is the volvo IC better then the stock IC off the T2

hopefully someone can awnser these few q's for me!! thanks!

Tyler

Sammymatik

1)The fuel regs I've looked at just have a hookup for the manifold pressure. SO when the the pressure increases, the rate of the pump increases to compensate. but i guess the answer would be that the fuel regulator is one unit which has a vacume sensor on it... like this one, this is a 1:1 rate regulator

2) I would say close enough to run a vac line would be good. Somewhere in the engine bay

3)this one i"m not exactly sure on. I've seen on somee cars the BOV mouonted on the IC. Not sure where I'd mount mine.

4)yes

5)I know I've read it somewhere off hand... I just woke up

6)A volvo IC is far better than the stock TII IC! Much bigger! About the size of the radiator! I have one if you need one? PM me.


Hope that helps some... but I'm not the expert in this area. Still learing myself.

pillage6

I'm using a Malpassi regulator and it works pretty well.

I believe they are pretty inexpensive since the are Australian and the conversion favors our dollar.

Eville140

Holley sells a raising rate reg. also.
I think you can also take a regular holley reg. Take the top off, drill and tap a hole and screw a small barb into it.

Later
Randy


There is a blowthrough group on yahoo, it is for piston cars, but I am sure you could pick up some carb ideas that would work also.

Later
Randy

REVHED

1. A rising rate regulator is actually a specific type of boost referenced pressure regulator. A normal 1:1 reg. raises the fuel pressure 1psi for every pound of boost pressure it sees. Whereas a rising rate reg. raises it by a specific ratio. If it's a 2:1 reg. then fuel pressure would be raised 2psi for every pound of boost. These are useful for EFI setups where you can get a bit of extra flow out of the stock fuel system when you crank the boost by increasing the pressure behind the injectors. For a carb system you want a normal 1:1 regulator.

3. It's better to mount the BOV closer to the carb. When the BOV is closer to the throttle plates there's less chance of the reversion wave actually slowing down the compressor. It's not one of those things that will make a whole lot of difference though.

jonfc3s

iTrader: (3)

has ne one used a racing beat intake manifold with their blowthrough setup? wondering if a 13b turbo will fit under it? let me know if u have,...... later

jonathan

82streetracer

iTrader: (1)

I am currently trying to fit a volvo intercooler in my 82
It is bigger than the rad and oil cooler combined.

I had to modify the belly pan (easy) and it is at a forward angle. Plus the drivers side hose is angled out but the pass side is strait. you will need some length of flexable hose to make it work. But if you use this cooler it should work great.

when Im done fitting it I will take some pix for yah.

bcty

ok so with the 1/1 pressure regulator (which is the one i should be useing right?) i send the fuel though it itself? and its acts as the regulator? or does it send a vac signal to another regulator mounted on the fuel line and that one controls the flow? just wondering if the 1/1 thing just senses the vac and boost and only does that?! thanks for the replys so far!

snf jonfc3s i have the RB manafodl and it looks like there plenty of room

RotorMotorDriver

iTrader: (1)

The rising rate regulator is the only regulator you will have.

It acts as a normal regulator at idle or when not on boost (6 PSI in your case). As soon as it detects boost from the manifold, it will increase the pressure on 1:1 ration (assuming thats the ratio regulator youre getting). I hope that clears it up.

I personally plan to get the Mallory RRFPR (Rising Rate Fuel Pressure Regulator) #4309. Its adjustable from 4-12 PSI (or something like that, I know 12 is as high as it goes), which will work fine for me and my low boost application for now. Its also very inexpenvie, like $75 on Summits website.

On a side note, the Cartech regulators can adjust the onset of the fuel pressure. AFAIK, no other regulator can do that. So with the Cartech, you could have it set as 1:1, but then later for somereason you want it 2:1, you can change it with the Cartech. Other brands AFAIK you have to buy a different regulator.

~T.J.

jonfc3s

iTrader: (3)

bcty , it looks like enough room, but i havent test fitted it yet

bcty

how high do the fuel pressure regulator risers work till like whats the max psi they go for.. i would love to get a 19-26 psi one.. not a varible one but are they made? i would guess so.. any good brands like the aeromotive above make one like this?

REVHED

1:1 isn't a rising rate regulator! A rising rate reg. increases the rate at which the fuel pressure rises as boost goes up. Hence the name.

RotorMotorDriver

iTrader: (1)

Well you need to compromise. Something that goes low enough to support your base pressure (6 PSI) and something to support your boost pressure AND base pressure. So how much boost would you want to run? 20 PSI is a lot . Plus, with fuel system, I think theres no such thing as overkill... Hint, hint .

~T.J.

bcty

lets say 15psi.. i think that would be good.. so a 21psi fuel pump so ill say 25 to be safe.. so this riser/reg i can set my min pressure.. thats all you need from a pressure regulator.. when will the T2 turbo start maxin out? will my engine over spool it? Well the Aeromotive there should be able to set the min right? but it doesnt say a max.. so hopefully that works? and how would i go about breakin in my engine with boost? hmmmm could be hard..

RotorMotorDriver

iTrader: (1)

What do you mean by over spool the turbo? The turbo has a wastegate that will open allowing the exhaust to bypass the turbo and keep it from over spooling...

~T.J.

bcty

sweet thanks...

ok now about carb hats.. i know K&N makes one.. though i cant find it in there catalog..



Would it be vary hard to make one? if i cant find this one.. is there any special design or just to make a seal around the top of the carb..

and breaking in the engine the boost should stay low if nto none.. this is a pretty free flowing system so i guess i would have to restrict the intake track to help with the boost? has anyone had an experence with moving the T2 intercooler up front? i know they arent great but its better then the stock location on the T2's..

cant wait to get this thing going..

Tyler

rotaryengineering

Here are my recommendations on your questions. Run a High Pressure Fuel Injection pump Bosch or Piersbugh type. In order for this to work you will need minumum 130 PSI capable pump. Then run a Malpassi they work great. I have tried most of the other brands available the Malpassi is extremly easy to use. When the regulator senses boost from the boost reference on your intake plenum the fuel pressure stays 5psi greater than boost pressure. So if your at 10psi boost then your fuel pressure will go up to 15psi. I have tried the Malpassi up to 45psi and it seems to flow pretty good.
You can refer to my web site http://www.rotarydragracing.com

Thanks
Albert Mets

bcty

i though this was discussed before that when the boost goes up 1psi the fuel also increases 1psi? so is this wrong ratio? have to take into account that more air is sucked into the engine then fuel.. i dont want to fool around with A/F math now

fatboy7

On a carb, you don't want a rising rate fuel pressure regulator, you'll flood the carb underboost. you want a constant pressure diferential between the manifold pressure, and the fuel pressure. Most pressure regulators (even stock) have a vacuum sensor that adjusts the absolute fuel pressure, so that it has the correct pressure drop to the intake manifold. This keeps the float levels constant. So during engine braking your manifold pressure is low (vacuum) the FPR lower the fuel pressure, so that the carb doesn't flood. The same goes for boost only in reverse.

RRFPR's set to anything but 1:1 would make it, so under boost the pressure differential would increase, and your float bowls would flood. RRFPR's are a band-aid anyway for an inability to properly tune (ie stock ecu) a FI car, so if your going stock FI,you'll need one of these.

So just buy a normal FPR making sure that it will be able to handle the boost+fuel pressure of your system.

bcty

but a normal fuel pressure regulator liek the holley one i ahve no wont increase under boost.. i need a riseing regulator.. or are you just talking about the break in? i am not going FI and keeping my carb... i was thinking though under boost the carb would flood if say i do 10psi.. there 16psi of fuel on a carb not ment for it.. what should be done? are there pressureized float bowls you can buy for a blow though app?

680RWHP12A

well since i have tons of blow through systems, here is my 2c!
a DCOE weber turbo plenum......

http://www.wankelracing.com/images/throttlebody.JPG


i can fab up any turbo plenum you could ever want or need , for any application!


as far as fuel press. regulators on carburated blow through systems go, you need a rising rate regulator of some kind!!! its a must or the carb under boost will go dry(no gas)

example;

lets say you use a standard holley regulated at 5 psi....
your boosting 7 psi with the turbo.... at idle the car will run fine, but when you make 7 psi (boost) with only 5 psi fuel pressure your gas will be forced back to the gas tank!!!!

now you have a boost dependant fuel press. regulator set at 5 psi....
you have 7 psi of boost(turbo) the fuel pressure will rise 1:1 so your fuel press. at 7 psi(boost) will be 12 psi(fuel) so your carb will still get fuel under boost!

the carb will not flood because of too much fuel pressure because your equalizing the pressure in the float bowl to compensate for the boost pressure...

a good fuel regulator for turbo applications available at any hi-performance store or mail order catalog is the Mallory model #4309... it costs around $85.00 and works great!

p/s its on the holley setup pictured above even!

bcty

thats aweseom! thanks! this should be stickey along beside the T2 into GSL-SE thread due to the fact this is cheep and pretty simple

nosajwrx-7

I agree, this is something I am interested in doing in the future, and it seams a lot of other people are also. Definitely sticky material!

680RWHP12A

here is a thread on a 13b turbo conversion i did , with video and dyno sheets....
https://www.rx7club.com/forum/showth...hreadid=155969

bcty

aweseome work 680.. hows the progress on your car? what did you max it out at? 730hp? what are your stats again?