Running Open Wategate.

[Silvia_Freak]

Hey guys.. I have a question. I was wondering if I could run a open wastegate? I'll be using a tail wastegate. I know a company who sells replacement springs for the tial. I was gonna use a .5bar spring. About 7 or so psi....So if I use a open wastegate do I have to use a boost controller? That leads me to another..Should I use the manuel controlller that my kit came with or save for a Electronic? HEre was my plan...Right now I have a turbo kit...Came with everything... But the fuel..Im running stock injectors with a walbro fuel pump. My goal is to only get 200 sum horses. That means I can run up to 8psi safely...

Tial wastegate open with .5bar springand Greddy boost gauge to watch for spikes?

Has anyone heard of the tial wategates spiking?

[Florida240sx]

Tial is the one you want. Make sure you get a true tial though not a knockoff. no need for a boost controller if oyu get the spring for the psi you want, or get a .5 bar spring and then want additional boost...You need some bigger injectors, get osme sr 370cc and get them cleaned or buy new 400-440 from deastchwerks.com our sponsor.Wht oyu got for tuning?SAFC ECU emanage?

[KATwo40]

Why do people cheap out on the most important part of the project???

Get some bigger injectors, please, so we don't have to read another post from you entitled, "Why did my car blow up?"

[Silvia_Freak]

SAFC. Yea imm check up on those NEW SR injectors.

[C-Kwik]

By open wastegate, if you mean divorcing it from the rest of the exhaust, then there should be no problems running it this way.

Boost controllers are a matter of preference. Manual ones are simpler and less prone to problems. Electronic units are nicer, but complicate it a bit, but can be slightly better in performance as it can give you slightly more boost as you reach the boost threshold. And so you know, unless you need to lower boost, there's no need for a different wastegate spring. You can simply use the boost controller to increase boost.

Any wastegate can spike if flow is restricted too much, in, out or through it. Electronic controllers may allow a slight spike as it reaches the set boost level.

As for your fuel system, a pump will not allow the injectors to put more fuel into the system. the Fuel pressure regulator will keep fuel pressure at the set pressure so any excess flow/pressure built up by a higher flow pump will be bled off either way. You either need to go to a larger injector with proper fuel management controls or perhaps even a rising rate fuel pressure regulator. Not doing at least either of these may cause you to lean out and detonate. Unless the purpose of your project is to see how many pieces you can make at the bottom of your oil pan, I wouldn't recommend running only a higher flow fuel pump. The factory fuel pump in good working order is adequate for supplying enough fuel for 7 psi with a RRFPR and up to about 10-11 psi(conservatively) with 370cc injectors.

[steve s14]

i'm running a tial 44 with a gt35 and an open wastegate and there is no spikes at all. in fact, once it opens, the boost practically flatlines.i know someone else thats running a tial 41 with a gt2871, that's plumbed back in and it doesn't spike either. if your running a good wastegate, you shouldn't have any problems, plumbed back in or open.

[KATwo40]

The largest chance of spiking really occurs when trying to run low boost on a small wastegate. Remember, the lower the boost pressure, the higher % of total exhaust flow goes through the gate.

Also, using a gate that's too small for a very high boost pressure will cause boost creep.

[steve s14]

very good point katwo40!!!

[babowc]

so.. for the wg, its bigger the better?

[Dustin240]

I have a open tial and it works great but sounds like crap.I'm at 7.25psi and 230hp- you will want more power very soon-.

Do it right the first time

[KATwo40]

so.. for the wg, its bigger the better?

Not always. You don't need a 44mm gate for a T25, since the gate would be just silly extra weight, and you might have some clearance issues, etc. For most applications, a 38mm gate is fine, from running low boost all the way up to boosting into the 425ish whp range. Remember, wastegate sizing is about total exhaust flow, not boost pressure.

Another downside of having a gate that's too large is you'll get gate shudder on low power applications. As you near your boost level, the gate begins to creep open (all wastegates), allowing some of the exhaust gas to exit before you reach full boost. If the gate valve diameter is too large, the gas will expel so quickly that the gate slams shut, then open, then shut, causing some shuddering and such.