35ounces

iTrader: (5)

In one place it says the evolution wastegate is good for 500hp and in another it says 400hp. Does anyone know what the diameter is?

At this point it would be interesting for Brad to chime in. Sure would be nice to get Turbonetics take on this.

Sharif@Forged

iTrader: (92)

The Evoultion is 36mm which is pretty small for this type of application. The Greddy Tial wastegates are 38mm and there are two of them.

I am not ready to agree that the wastegate is too small, as so many dozens of people, inlcuding Peking's car which I tuned with his 3 inch exhuast, have had no problems at all holding the preset boost.

I am sure that space constraints kept TN from including a larger wastegate.

kcobean

iTrader: (2)

Jet indicated that he saw a significant decrease (about 1.5 PSI) in peak boost value by adding in the silencers to his mufflers, which effectively decreases the diameter from 3" to 2". So we have a demonstration of backpressure helping to control gate operation. Slowing down the turbine seems to have a bigger effect on gate operation than backpressure. The question is what does it do to the tune, and is it better to have a restrictive exhaust on this kit, or a bigger wastegate (especially given the tight spaces that the gate sits in.

35ounces

iTrader: (5)

Of course more backpressure will effect the turbo but I'd certainly prefer to control boost via precise wastegate operation then try to do it with backpressure which is just making the turbo work harder.
It would certainly be nice to know if it is the wastegate not flowing enough, or the dump tube design, or just an issue with your WG signal.

Alberto

iTrader: (14)

IIRC the T-netics Z that AAM did for Modified mag was pushing 14psi with no issues controlling the boost, so how would you explain your theory against that car which made over 450whp and 500ft/lbs?

What I dont understand is why a few guys running the Greddy Evo mod'd are having this problem, and people are thinking maybe its the exhaust is to free flowing, but the Borla TD guys such as Laww are not having this issue, and they are both 2.5" TD exhaust(before the reverse y-pipe of course), and should be flowing very similarly. Could it just be a bad coincidence that guys running the Evo2 are having this issue, or does it pertain to their exhaust systems?

MIAPLAYA

iTrader: (3)

+10000 I just said the same thing on the other thread. I think the wastegate will hold the pressure since it does at 14 PSI on the Modified Mag car with 450 RWHP and 520 ft/lb of tq. Something else is amiss with Kelly's car. The reason why Jetpilot boost increased so much is that there is no boost control on the car and he is essentially bolting on an open exhaust. You could do two things. Switch out for the 7 PSI spring on the wastegate or buy a boost controller. Or both

35ounces

iTrader: (5)

I hate these dueling threads!

He made a point, that may be valid. At low boost pressure the WG has to flow near max capability and it may not be able to do that. That would leave us with a lack of boost control at low boost levels with ideal flowing exhausts.

MIAPLAYA

iTrader: (3)

While this is close I won't say thats exactly accurate. Consider it this way...with higher boost the wastegate opens for LESS amount of time per cycle. BUT when it does open due to the increased air flow from the higher horespower it has to flow MORE air then it does at 8 PSI and 380 HP. So then the possiblilty would be that it is not able to cycle FAST enough at lower boost not that it cant flow enough air.

JETPILOT

iTrader: (51)

Best place to get the 7 PSI WG spring ASAP?

Respect
JET

MIAPLAYA

iTrader: (3)

Turbonetics..call Reggie 805-581-6710

35ounces

iTrader: (5)

If that was the case then boost would SPIKE but Kelly is seeing consistent high boost. Also, the boost controller that Kelly installed would help resolve the issue.

MIAPLAYA

iTrader: (3)

This is true. Hey maybe I am wrong. I don't design turbo systems for a living so I'm sure I am wrong. Either way, I would try the 7 PSI spring first. If that doesn't work its cost you nothing but a little time.

35ounces

iTrader: (5)

LOL. I am not convinced that the WG is maxed out either but is an interesting theory.
Just for interests sake do we know what other WG's might fit? Do any of the TurboSmart wastegates fit?

MIAPLAYA

iTrader: (3)

The Tial 38mm will fit I think. Whether 2 mm is going to matter I dont know. Turbonetics may have something else we can try though. I'll call Reggie and Brad and see what kind of info I can get.

BlackTuner

iTrader: (2)

Ok, it's pretty simple. HP is not the deciding factor on what waste-gate to use. It is CFM. When using the factory exhaust your exhaust gas will flow the least direction of resistance. In your case was your waste-gate. Now with your high flow exhaust system that path of the least resistance is your turbocharger. Two things can cause this, the incorrect placement of your waste-gate or undersized waste-gate. A lower spring tension on the waste-gate could help or replacing with a waste-gate that can flow more cfm.

Thanks,

Jermaine~

JETPILOT

iTrader: (51)

Exactly.....

Wastegate piston travel is also important to the total CFM flow as is piston size, as well as the angle the wastegate is mounted to the exhaust stream. 90 degree mounting angle works well with the stock exhaust but may become a limiting factor and slow gas flow in a car with an open exhaust where the gate is required to flow more.

Respect
JET

MIAPLAYA

iTrader: (3)

I agree 100%. Its just hard for me to accept it 100%. Some cars have dropped the exhaust all together and not had an increase in boost pressure. While others have just bolted on a 3" exhaust and increased boost pressure. I just talked to Turbonetics and they have an 05 Z in the shop right now. They are going to research this today on that car. I should know sometime today or tomorrow what they come up with.

taurran

iTrader: (18)

I think Kelly is already running the 5psi wastegate spring.

By the way, what size piping is the Greddy evo2? From what I understand it has pretty small piping.

Alberto

iTrader: (14)

IIRC 60mm which is 2.38"....

BlackTuner

iTrader: (2)

It doesn't surprise me at all, measurements are only as good as the tools and user used to measure. If you don't pay close attention it is something you will let slip by. I bet there is a correlation between these types of incidents and blown motors as well.

Jermaine~