cheap boost controller (home depot)

[83turbo280zx]

anyone know what i need to make a boost controller for my 83 turbo 280zx? i wanna push my boost to 10psi and i need to know if anyone knows what i can use from home depot to do it, will i need to do something with my pop off valve? and will i need some kind of boost sensor bypass or adaptor that will trick it so i wont have my fuel cut off?

 

-83 280ZX-T 73K original miles greddy type s BOV, Sony XPlode 1200watts w/ 2 Visonik 12's, NGK Spark Plugs

[jknc90]

Why home depot?

[83turbo280zx]

well doesn't even have to be home depot, just where ever? lol you know anything?

[CArFAn]

Had this bookmarked as a "just in case".

 

http://www.geocities.com/chmwatson/FAQs/mbc.html

[83turbo280zx]

Had this bookmarked as a "just in case".

 

http://www.geocities.com/chmwatson/FAQs/mbc.html

 

 

thanks a lot man!!

 

do you know if i need to do anything with my pop off valve and boost sensor?

[CArFAn]

I never actually made it i just seen it and thought if someone needed it i would be able to show them. As for the blow off valve and boost sensor i do not know but i do know that you will need a boost gauge accurately show what boost you are at so you will not over boost and kill your motor.

 

Im not expert on turbo motors I'd wait for someone more knowledgeable to chime in on this.

[83turbo280zx]

oh, well i have a pop off valve and a blow off valve, 2 different things, the pop off valve is on my intake manifold and opens up after a certain amount of boost to keep from overboosting, i'll have to search around and find what i can, thanks for the page about the mbc!!

[Calgary280ZT]

By the time you fart around with a home made controller and pay for parts, you can buy a controller from http://www.3barracing.com/product_6.htm these guys for $47. Works for me. We plugged off the pop off valve, lots of people do, no problems yet.

[cockerstar]

Take a look at this one too

[mario_82_ZXT]

Including shipping, this is probably about as cheap as making it yourself:

http://cgi.ebay.com/ebaymotors/NXS-MANUAL-BOOST-CONTROLLER-300ZX-GSX-GST-STI-RX7-MBC_W0QQcmdZViewItemQQcategoryZ33742QQihZ016QQitemZ260228635515QQrdZ1QQsspagenameZWDVW

 

Also, for the pop off, just shim it. Drill the center rivet out, disassemble it and and some washers to shim it and make it harder for it to open. Mine's currently set at 12psi as I used to run 10 unintercooled.

Mario

[hughdogz]

I also made my own MBC using a 1-way adjustable valve from Grainger / McMaster-Carr.

 

Anyhoo, if I were to buy an MBC today, I'd go with one of these bad boys:

 

 

Hallman! (clicky)

 

[Edit: Like Mario said, drill the rivet on top just enough to pop the cover off. This way the cap will stay put when it is back on. You can get bigger washers and find a stiff spring from the hardware store and shim the valve shut. But you shouldn't be boosting more than ~9psi non-intercooled, I guess you can do ten but I'd be using hi-octane gas for sure.]

[Gollum]

Including shipping, this is probably about as cheap as making it yourself:

http://cgi.ebay.com/ebaymotors/NXS-MANUAL-BOOST-CONTROLLER-300ZX-GSX-GST-STI-RX7-MBC_W0QQcmdZViewItemQQcategoryZ33742QQihZ016QQitemZ260228635515QQrdZ1QQsspagenameZWDVW

 

Also, for the pop off, just shim it. Drill the center rivet out, disassemble it and and some washers to shim it and make it harder for it to open. Mine's currently set at 12psi as I used to run 10 unintercooled.

Mario

 

That's the one I plan on running. Once you factor in time that's cheaper than I could make it for.

 

And a stock L28ET can take 10PSI easy... but the turbo won't like it. A BOV is a MUST. The guy I bought my turbo donor from has quite a bit of experience with L28ET motors and tuning as many factory components as possible (he's on Zcar a lot, not here much though) and he blew a motor at 10PSI because the turbo couldn't take the pressure from not having a BOV. Without an intercooler there just isn't anywhere for the air to go once the throttle closes. Easy way to kill a turbo.

 

If you raise the fuel pressure to make sure you don't go lean it shouldn't detonate. Factory recommended 93 octane at the stock 7psi... I've been running on 87 octane. Just be mindful of your air/fuel ratios and understand how much timing you can run.

 

Beyond 10PSI an intercooler would definately be recommended though.

 

EDIT: I know it seems as though I didn't know you had a BOV, I did. I'm just making sure you understand how vital it is, and to make sure it's opening correctly and funtioning the way it should.

[hughdogz]

Hi Gollum, I don't doubt anything you and Mario said about being able to boost to 10psi. Those are good points you make about making sure your AFR's don't go too lean.

 

When my bone stock L28ET was at the dyno I was running lean above say 4750 RPM.

 

Also, doesn't the stock L28ET manifold have a built-in bypass valve (to protect against surging) for when the throttle valve shuts? Why is a BOV so important with regard to boosting above 7psi if the stock bypass valve is working as it should?

 

I'm not trying to argue with you guys, and you're probably more on spot than me, but I just want some more insight into your reasonings.

 

Thanks and Best regards, -Hugh

[Noddle]

You may want to look at this

 

http://cgi.ebay.com.au/Turbotech-manual-turbo-boost-controller-THE-ORIGINAL_W0QQitemZ200215056466QQihZ010QQcategoryZ130654QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

and here's a link to a page that talks about it

 

http://www.skylinesaustralia.com/forums/good-cheap-boost-contr-t73375.html

 

Nigel

[mario_82_ZXT]

We might think of it as "dangerously lean" but some people have seen how much fuel you can pull out of the engine after torque peak.

 

Tony D has posted on this a lot I believe.

 

Also, in my experience the stock recirc (found on the #4 intake runner) was good for 10psi until I added the intercooler and piping. I started getting what sounded like surge, I think it couldn't vent all the extra volume of air in the piping.

 

Mario

[Gollum]

Well there is a stock bypass, and some have said it's good to 10PSI... but I'd be very cautious at that point. It's really only designed to handle the 5-7psi that stock delivers. 10PSI is a LOT more air, especially if you have an intercooler like mario talked about.

 

You have to consider how short the stock piping is. If you venture beyond the capability of the stock bypass then the air has NOWHERE to go. It's not hard to put excess pressure on the turbo and start destroying it.

 

I'd also like to know what your A/F ratios were on your dynos. The L28ET goes lean on top almost no matter what, I think it has to do with the stock fuel curve. So don't expect it to hold a 10.5 or 11:1 ratio. Odds are it'll run really rich at the bottom and then lean out.

 

Here's a dyno from bastaad, who was running a MSD fuel pump on a stock motor running 10 PSI. No intercooler, stock pressure regulator, etc.

 

 

He says after that he tweaked with the timing a bit and go it to 200 RWHP. Not bad for a stock motor.

 

Then he installed an intercooler + BOV and raised to 12 psi

 

 

Started getting REALLY lean, and I personally thing he could have just raised the fuel pressure with an adjustable regulator, he sprung for a rising rate one (though it really bugs me that most of these units only raise about 1-2 psi of fuel for ever 1 psi of air, when it needs to be more like 5-7psi in most cases).

 

He raised the boost to 14psi but has having boost fall off problems and was only at around 10psi by 6k

 

 

All dynos were done on dynojets. With nothing but a fuel regulator you can squeeze a lot of power out of these motors. But I think bastaads progress should give people a good idea of what's "safe" and what power levels are expected. I personally thinkg a BOV + intercooler should be one of the first mods, before a boost controller, but others have had some sucess the other way around, so it's just preference.

[83turbo280zx]

Hi Gollum, I don't doubt anything you and Mario said about being able to boost to 10psi. Those are good points you make about making sure your AFR's don't go too lean.

 

When my bone stock L28ET was at the dyno I was running lean above say 4750 RPM.

 

Also, doesn't the stock L28ET manifold have a built-in bypass valve (to protect against surging) for when the throttle valve shuts? Why is a BOV so important with regard to boosting above 7psi if the stock bypass valve is working as it should?

 

I'm not trying to argue with you guys, and you're probably more on spot than me, but I just want some more insight into your reasonings.

 

Thanks and Best regards, -Hugh

 

well the engine has a stock pop off valve, which is not the same thing, the pop off valve is on the back of the intake manifold, close to the egr valve, its only purpose is to keep the engine from over boosting incase say your hose on your wastegate came undone, it would let all the potential pressure from ur turbo get into the engine, and 14 psi is dangerous w/o an intercooler or blow off valve, so it opens to let the excess pressure out. a blow off valve is inline between the throttle body and the air outlet of your turbo, i.e. your intake piping. when the throttle closes, the turbo is still spinning, thus still producing air, when the throttle plate closes that air has nowhere to go, so it rebounds back to the turbo, causing it to slow, or in extreme cases stop or spin backwards, very bad for it, and the more psi you have the more risk you have of damaging your turbo this way, so the blow off valve lets that excess air out so it doesn't damage anything, and keeps your turbo spooled up

[hughdogz]

Also, in my experience the stock recirc (found on the #4 intake runner) was good for 10psi until I added the intercooler and piping. I started getting what sounded like surge, I think it couldn't vent all the extra volume of air in the piping.

 

Well there is a stock bypass, and some have said it's good to 10PSI... but I'd be very cautious at that point. It's really only designed to handle the 5-7psi that stock delivers. 10PSI is a LOT more air, especially if you have an intercooler like mario talked about.

 

You have to consider how short the stock piping is. If you venture beyond the capability of the stock bypass then the air has NOWHERE to go. It's not hard to put excess pressure on the turbo and start destroying it.

 

Ahh…I get it now. Thanks for explaining this guys. I seem to remember the stock bypass valve connection openings on the J-Pipe and 4th intake runner couldn’t be much bigger than ½”-3/4” (~12-18mm). That (maybe also the type of valve) would definitely be a bottleneck considering most BOV / recirculation valve are perhaps 38mm+.

 

 

I'd also like to know what your A/F ratios were on your dynos. The L28ET goes lean on top almost no matter what' date=' I think it has to do with the stock fuel curve. So don't expect it to hold a 10.5 or 11:1 ratio. Odds are it'll run really rich at the bottom and then lean out. [/quote']

I’ll have to dig out that old dyno graph from Torque Freaks…it was probably five years ago.

 

well the engine has a stock pop off valve, which is not the same thing, the pop off valve is on the back of the intake manifold, close to the egr valve, its only purpose is to keep the engine from over boosting incase say your hose on your wastegate came undone, it would let all the potential pressure from ur turbo get into the engine, and 14 psi is dangerous w/o an intercooler or blow off valve, so it opens to let the excess pressure out. a blow off valve is inline between the throttle body and the air outlet of your turbo, i.e. your intake piping. when the throttle closes, the turbo is still spinning, thus still producing air, when the throttle plate closes that air has nowhere to go, so it rebounds back to the turbo, causing it to slow, or in extreme cases stop or spin backwards, very bad for it, and the more psi you have the more risk you have of damaging your turbo this way, so the blow off valve lets that excess air out so it doesn't damage anything, and keeps your turbo spooled up

 

Yes, you are right that there is a difference between a safety pop valve and a Blow-off / recirculation valve. The stock L28ET does employ a sort of bypass valve which is what I was wondering about, not the safety pop valve. Good summary of why you need a good BOV / recirc valve ‘83!

 

So, this leads me to a new question of whether or not I should run my HKS recirc valve as recirculating or vent to atmosphere after I install my T3/T04E this summer. I need to reseach more. Cheers Guys!

[Gollum]

I personally feel it's better to route the BOV as a recirc as it will help keep the turbo spooled, then you also don't have to worry about the EFI going rich or anything.

 

Recirculating the air well help keep the engine much more responsive on throttle changes. I think the ONYL reason people ever vent to atmoshpere really is for the sound, either that or they're lazy. I personally HATE the idea of adding a BOV just for the sound as that's as rice as rice gets IMO. But that's just an opinion.

 

Turbo engine's exhaust is quite, and keeps you out of trouble. Why add a cop wistle to the car?

[hughdogz]

More wise comments Gollum!

 

I'm probably going to stick with my recirculation setup for the new Turbo. I hope it still works well.

 

I'm still foggy on how the HKS surge tanks work (and Monzter's holy grail project) with regard to having the BOV attached to it venting to atmosphere. I believe you need either ITB's or tripples...I'm guessing it keeps the turbo spooled as much as possible and bleeds off the unnecessary charge.

 

I wanted to have the BOV attached to the intake manifold that I plan to make, but I'm pretty sure you would need throttle plates after the manifold in order for it to work.