Whadda ya think?

[longlivetheZ]

I'm considering this approach:

http://cgi.ebay.com/ebaymotors/ws/eB...MakeTrack=true

http://cgi.ebay.com/ebaymotors/ws/eB...e=STRK:MEWA:IT

I'd prefer a Greddy Profec B Spec II, but why spend that extra $200+ if these will get me the same end result? The turbo FAQ on Z31.com mentions that a manual boost controller won't let the boost build as fast or as smoothly as a electronic fuzzy logic one, but does this really make THAT much of a difference? I guess a better question would be, does it make a big enough difference to warrant spending another $200+? I'd think this setup would work just fine.

[k3smostwanted]

looks good to me...i dont see why it wouldnt work. with names like greddy you are paying for an above par product but you are also paying for the name too. but then again it is greddy and they are known to be above the competition when it comes to things like that.

[MikeMan]

If you wanted to go really dodgy, you can up your boost using a $3 screw valve and some hose. The reason fuzzy logic boost controllers sell is because they help eliminate boost spikes, which is really going to keep your VG30ET in good condition. Even if you've got your manual boost controller fooling the wastegate into opening at a modest 10psi, the wastegate can still only reduce the turbo's boost at a certain rate.

Scenario: You're flooring it in 3rd, get up to 5000rpm, making 10psi of boost and you do a lightning fast change down to 4th. Your tacho drops down to 3500 rpm or so, but the turbo is still pushing enough air to create 10psi of boost at 5000 rpm, not to mention the charge of air produced when you closed the throttle body for that split second. This would probably translate into about a 14-16psi spike. The wastegate slams open, desperately trying to let the turbo spool down. This only takes half a second or so, but for that half a second, your engine was:
1) running quite lean
2) overboosting
3) probably detonating like crazy due to the previous two points.
If you're lucky, it will might just give you a few little pits in your pistons.
If you're unlucky, it can blow some holes through your piston, blow a head gasket, damage your rings etc.

Now, with this in mind, I know a few people with dodgy $3 screw valves operating their wastegates, running high compression engines (RB30E with turbo bolted on running 14psi) who still get huge boost spikes but haven't had any problems from them. Before these fuzzy logic controllers were invented, everyone used manual boost controllers. However, the technology exists now that can prolong the life of your turbo engine substantially.

If you had a little WRX or something I'd tell you to go for the manual boost controller option, but don't put your VG30ET in pain. It doesn't deserve it..
If you do get the manual boost controller, and you're running any serious amount of boost, please at least get yourself a bigger wastegate and a blow off valve (preferably plumb back of course.. )

Besides, the fuzzy logic controllers look just so damn cool too.

-Mike

[Broke_as_****]

Well one of the perks of the digital ones is that often you can buy a seperate harness set that will allow you to read out A/F ratios, all manner of electric factors, precise airflow measurements and plenty of other useful info.

[freakonaleash1187]

i say spend the extra $200, it will be probably worth it in the long run. plus, like broke said, it has lots of other fancy stuff.

[longlivetheZ]

I have a turbo timer in the mail right now and I will get a BOV soon. I've heard about the fishtank/bleeder valves before and I've known people that use them...one of which happened to be on a WRX, as a matter of fact. Yea, they're cheap, but they also don't work well. That WRX was pinging like hell. I wouldn't use one of those because I KNOW that they have boost creep/boost spike problems. There are different kinds of manual controllers. This boost controller in question was designed for this purpose so I'm thinking they took measures to reduce these problems. Besides, you can rest assured that I'm going to drive around with one eye on the road and the other on the boost guage for about 2 weeks to make sure that I'm not over boosting anything. The weather is getting cooler here, so the conditions for upping boost are pretty favorable...I would NOT let it detonate or overboost, nor would I crank the boost up when it's 90 outside.

I know the electronic do-dads do a trizbillion different things, but the vast majority of them, I don't think I want to pay for. I plan on installing a A/F ratio guage and an exhaust temp guage so I can keep a better eye on everything. This is just the coolest, trickest little thing ever when it comes to air/fuel ratio control and monitoring. I'll probably get one of these down the road instead of just an A/F ratio guage.

Nothing's permanent...I'd probably get a Greddy down the road...I just don't have the cash right now.

[Broke_as_****]

Originally Posted by longlivetheZ

I've heard about the fishtank/bleeder valves before and I've known people that use them...one of which happened to be on a WRX, as a matter of fact. Yea, they're cheap, but they also don't work well. That WRX was pinging like hell.

That always kills me that someone will spend 30 grand on a car then stuff wielding tips or something in a wastegate hose to up the boost...

[MikeMan]

Yeah, you're a sensible bloke. As long as you keep an eye on the spikes during spirited driving, you'll be fine. Let us all know how it goes.

-Mike

[longlivetheZ]

I am smart about this. I'm not a moron like I referred to before (my pinging WRX friend) or Broke refers to (welding tip lovers...aka...boost jets). I will not settle for something that MIGHT work alright or MIGHT not hurt my beloved VG.

I posted this same exact topic on Z31.com's board (of which has also been graced with our wonderful "oil pan" friend...I'm still amazed at how fast that got around...) and a couple people on there recommended the $3 bleeder valve approach. Uuuuuuuuum no.

So...I opted for the best of both worlds: The goods of an electronic controller...accurate boost response and the goods of a manual controller...cheap as fuck. The end result is a "ball and spring" type manual controller. This is designed to give accurate boost response without spikes, yet it only cost me $15. All of you rest assured that I'm going to have one eye ball plastered to that new boost gauge for the first few WEEKS I'm running this setup...if I see one spike, that bitch will be ripped out before you could say "holy VG30ET, batman". There will be no "hole-y" pistons in my house. The great thing about this is that, not only will it serve it's purpose until I get going at the new job and get my Profec, but it's so cheap that I can chuck it if it does me wrong.

It's a win win situation.