What Size Boost Jets Do I Need To Run

[R33GOD]

for the tech boys

i will be using my hks actuator to control my boost setting at what ever the spring rate is set to which i think is 12-13 psi.

just want to know what size boost jets should i run to achieve 15 psi.

for the r33 gtst

thanks guys.

Edited December 30, 2007 by R33GOD

[GeeTR]

Jesus chr_st, what on earth is a boost jet?

[Mr. Oizo]

two of the big ones

[DjeMz]

lol @ carby jets..

welcome to the efi future my friend

[R33GOD]

The jets fit in the end of the wastegate vacuum hoses. These attach to the fittings on the intake pipe before the rubber intake hose that feeds each throttle body.

boost jets....

if you guys go to the 300zx forum they clearly tell you what they are and how to install them.

my dad done it on his 300zx. stock setup. runs 12 psi nicely with no boost spike

[Mr. Oizo]

The jets fit in the end of the wastegate vacuum hoses. These attach to the fittings on the intake pipe before the rubber intake hose that feeds each throttle body.

boost jets....

if you guys go to the 300zx forum they clearly tell you what they are and how to install them.

my dad done it on his 300zx. stock setup. runs 12 psi nicely with no boost spike

Boost controller or boost jets:

Boost controllers and boost jets are the recommended way to increasing your boost pressure. Adding a boost controller essentially tricks your waste gates, waste gates vent boost allowing the car to just run at 8 psi. The boost controller or boost jets trick the waste gates into thinking that there is less boost than there really is meaning you will have a quicker spool up time and a large increase in total boost pressure. Boost pressure equals power. Running higher boost pressure is only capable after an ECU upgrade. Investing in a turbo timer is also a good idea when running higher than stock boost, as a turbo timer will help cool your turbos when its time to shut down.

i'm still confused

[W0rp3D]

WOW, upping the boost to 12psi will help my turbo spool quicker........

And i need an ecu upgrade to run higher boost....

The only thing i can think a boost jet is would maybe be a tube of something with a smaller hole in the centre so it lets less air through to the wastegate.

Just get a boost controller and do it properly from the start.

[R33GOD]

WOrp3D the whole point of this is not to run a boost controller, to keep the mods and stealthy as possible with my setup. And to keep the cops from giving me a defect

[R33GOD]

people that mock this way of boosting a car dont know about this method. need some tech guys who know what there talking about and that have played around with these jets.

[W0rp3D]

buy a waste gate that is made to run higher boost then.

[R33GOD]

you mean actuator?

ive got that.

[W0rp3D]

yes i mean an actuator, most of the ones i have seen are adjustable so it should do a fair bit of boost, with one of these i dont understand why you need the extra bits.

You hav'nt really explained your self very well, got any pics of what you are chasing?

[R33GOD]

reason why i dont want to depend just on the actuator is because iv'e heard from a few people so far that when you run them on what there set from factory (12-13psi) they work better than a boost controller but when you try to increase the boost pressure through the rod boost will come on abit slower and will tend to spike.

no pics at this stage mate

[Ionos]

Just so I understand, boost jet is a fancy name for a non-adjustable bleeder type boost controller, right?

Never heard it called that before. Anyhow, bleeder valves are generally the worst type of boost controller.

If you want to do it on the cheap, you'd be better off installing a precision spherical coil actuated pressure regulater install, which is more commonly referred to as a ball and spring boost controller. There's a great one on ebay for about $35, search for 'Turbotech'.

[GeeTR]

people that mock this way of boosting a car dont know about this method. need some tech guys who know what there talking about and that have played around with these jets.

rofl

I wouldn't think you'll find a "tech guy" as you mention it, using one of these "boost jets" on a skyline for obvious reasons. A $20 bleeder would prolly be a better option

Note my use of quotation marks for "boost jet", much like "Santa Clause" "Easter bunny" and of course "hot lesbian"

I wish you luck

Edited December 30, 2007 by GeeTR

[33gtst]

I guess the only plus to these inline restrictors is the are undetectable by the popo. But hang on dont nissan already use them???

[R33GOD]

yes they do. your just changing it to a different size. there actually mig welding tips

[dangerman4]

forget the term boost jet and call it what it actually is. A "Restrictor"

its a small piece of steel tube that is fittted snuggly inside the actuator supply line from the manifold.

it has a smaller hole in the middle approx 2.5 - 3mm compared to the 6mm rubber line.

im running one in conjunction with my PFCBC and a 18psi actuator and i have no issues controlling boost up to 27psi.

ramps onto boost hard, and then stays within 1psi to redline.

and just to clarify an earlier remark in regards to increasing boost can make it come on sooner.

if your target level is close or just past your actuator tension, then your internal gate flap will allready be opening before you reach your target boost as to control the clime in pressure. If you were to run a heavier actuator and run higher boost then the flap will stay completely shut for longer causing it to ramp up harder and earlier.

not 1000rpm sooner but certainly 100 - 300rpm sooner.

[R33GOD]

thanks for that mate. im just after what size restrictor to use for 15-16psi tops.

[Sky'sDeLimit]

FYI.... Sydneykid had posted this earlier on a different thread [http://www.skylinesaustralia.com/forums/Jaycar-Boost-Fuel-Contro-t61207.html&st=20], may be of assistance?

" 30 Jan 2005, 10:59 AM Post #37

I thought everyone with an RB25DET knew how to do it. You just disconnect the solenoid (vacuum, not electricaly), connect the boost feed directly to the wastegate and use the (standard) restrictor to bypass the desired amount back into the turbo inlet. The standard byspass hole of 1.25 mm bypasses enough air flow for 0.5 bar. Tools needed = one pair of pliers and 10 minutes.

PS; If you want more boost you can drill out the bypass, 1.5 mm = more boost (around 0.7 bar) 1.75mm = a bit more (around 1.0 bar). But the Jaycar Boost Controller needs the bypass to relieve trapped pressure between the solenoid and the wastegate actuator. So I don't want to redrill the restrictor only have to solder it back up again."

"This is the 10 minute no cost boost to 0.5 bar rerouting of the vacuum hoses. Disconnect the two vaccum hoses from the solenoid. Then connect the boost feed (from the cross over pipe on the left of the picture) to a the standard T piece. Connect one side of the T piece directly to the wastegate actuator (on the right of the picture). The remaing connection on the T piece goes back into the inlet via the BOV return pipe (on the standard fitting). Make sure to put the the standard brass restrictor in that vacuum hose to bypass the desired amount back into the turbo inlet. The standard bypass hole of 1.25 mm bypasses enough air flow for 0.5 bar."

If I could work out how to insert the photo I would have soz lol... noob here... hope it helps whoever :-)