Peking

iTrader: (2)

Fact right, ok dude.

I am to tired to keep with going back and forth with you on this. What do you want, like our blessings or something

Like I said in the other thread, if this is true... Then all of us would have similar boost problems... And from before my upgrades through Sharif, boost was constant 8psi. So maybe me and the others have magical wastegates lol.


Wow we went from being a Turbonetics little family, to we can't even get along since we don't see eye to eye on something.

JETPILOT

iTrader: (51)

Don't worry..... u still my Turbonetics borther from another mother.

Respect
JET

Peking

iTrader: (2)

Sorry folk, I was getting out of line with my posts.


You too are my Turbonetics brother from another mother LOL.

kcobean

iTrader: (2)

I still personally believe we're not looking at an undersized gate issue because all the other folks with stock exhausts running a 9 PSI spring (some of them generating within 10-15 WHP of the 394 I'm getting) are not having this issue. I would buy that we have "unbalanced the system" somehow with the free-flowing exhaust. The question then is how to fix it. We're not flowing any more exhaust gas than anyone else because the intake and exhaust piping is all the same size for all of us until you hit the post downpipe piping. What is it about the post-downpipe piping that could cause this?

JETPILOT

iTrader: (51)

We are flowing more exhaust volume, and we are asking the wg to do a larger portion of the work since we are not asking for more boost.

The only factor for me was changing my exhasut. My stock exhaust didn't produce this problem. 10 minutes later after installing the new erxhaust.... problem. WHY? free flowing exhaust increasing airflow through the motor by spooling the turbo up sooner. More exhaust volume, no increase in boost = bigger burden on the waste gate.

The stock exhaust was keeping things in balance by creating backpressure and limiting flow/volume.

Respect
JET

kcobean

iTrader: (2)

Maybe it would be easier to assign some key/pair values to things....like this (and the values are fictitious, but they work for the purposes of demonstration)

on a car with a stock exhaust system, let's assume that we go WOT at 2K RPM, so throttle is constant.

Engine RPM......Turbo RPM
--------------------------
2000...............20,000
3000...............30,000
4000...............40,000
5000...............50,000
6000...............60,000
6600...............66,000

Ok, fine. Now lets assume that a free-flowing exhaust on the same car causes a 10% increase in turbo spin rate at a given engine rate...the values are now:

Engine RPM......Turbo RPM
--------------------------
2000...............22,000
3000...............33,000
4000...............44,000
5000...............55,000
6000...............66,000
6600...............72,600

This increase in velocity of the exhaust turbine would result in an increase on the compressor turbine as well, which means that for a given exhaust rate, we are getting more intake charge under boost than the stock car. As a result, we get even more exhaust gas which requires the wastegate to vent vent considerably more air than the gate on the stock car is required to vent. It's easy looking at it this way to see how a free-flowing exhaust may not work well with the existing gate.

JET, keep us in the loop on what you find. If you're right, from what I understand one of the TEIL gates apparently will bolt right up to this existing flange, assuming it will fit in the space available.

JETPILOT

iTrader: (51)

The TiAL that bolts up is only 38mm..... same as the Evolution.

Respect
JET

JETPILOT

iTrader: (51)

Here's an interesting tidbit of information to back up my theory.... just found this in the FAQ section of the turbosmart site.

Wastegates - Facts and Fiction

The more powerful the engine, the bigger the wastegate you need!

This is one of the more popular misconceptions. Use this simple guide before setting out to find the biggest wastegate you can afford.

Big Turbo/Low Boost = Bigger Wastegate
Big Turbo/High Boost = Smaller Wastegate
Small Turbo/High Boost = Smaller Wastegate
Small Turbo/Low Boost = Bigger Wastegate

Respect
JET

BlackTuner

iTrader: (2)

I have just skimmed through this post I continue to notice a few interesting points of what is going on here.

First I will say what is a known fact. On a 350z with FI at 7-8 PSI you will max out your factory MAF. At approximately 4750 rpms you are pegging your MAF Voltage. Your MAF actually counts the amount of air usually in gram of air per second. Pegging your MAF means your car does not have a clue how much air is being injested in to the motor. Whatever the cause of the increased boost, wastegate and high flow exhaust. Maxing the MAF is never good.

If your dyno session was done on a typical 70 degree day and now you are rolling around on a 35-45 degree day. Even at the same boost pressure your vehicle is injesting more air due to air density. Actually per my calculation you have about 9% more density. This alone will cause your car to lean out. Now couple that with 3 more psi at least and the same injector on times for you to reach a previous 10.0 afr. I bet it has leaned out quite a bit.

Reformulated Gas...
Oh my, this is the craziest variable ever. When we reach the winter time, we are often are switched over to reforumulated gas. Since reforumalated gas contains Oxygenates of up to 10%. Between Gas and Air Density all of the additon Air and no extra fuel to compensate. This is not sounding like a good recipe.

Thanks,

jermaine@turboxs.com

MIAPLAYA

iTrader: (3)

Ok guys I'm not going to restart the argument but I will say this...at 15 PSI on the Evolution wastegate Modified MAgs 350z was making 465 RWHP and 520 ft/lb of tq. Thats at 15 PSI on THIS turbo and THIS wastegate. The wastegate will flow enough for that much air. I think the issue at hand is that by opening up the exhaust the car is running more airflow and it is raising the boost as a result of no boost control. It happens in the 300 Z Twin turbo world all the time. You can bolt on a open exhaust and get another 2 PSI of boost just by doing that.

JETPILOT

iTrader: (51)

That's why you need to get me my UTEC ASAP before anyone else get's theirs..... I have special needs.

Sens this one special unit FedEx to Sharif.... he knows who it's for.

Respect
JET

JETPILOT

iTrader: (51)

We all have Evo wastegates installed. What is the issue with the waste gate that won't dump and hold boost at 8PSI. The waste gate should hold boost regardlesss of what exhaust is installed. The only info the wg will get is...."wow that's 8.5 psi. I better open up." It doesn't sense back pressure from the exhaust.

Again the more boost you need the less work the wastegate has to do. @ 15PSI that gate is flowing a hell of a lot LESS air than @ 8PSI.

Respect
JET

MIAPLAYA

iTrader: (3)

I understand what you are saying. What I am saying is there is a simple way to find out of the wastegate flows enough or not. Install the 7 PSI spring in the wastegate, You currently have the 9 PSI spring in there. With the 9 PSI spring you are getting 11.5 PSI. With the 7.5 PSI spring you would by theory be getting 9.5 PSI. If it does then the wastegate works fine. Its cheaper then switching wastegates right away. And it would prove for good whether the wastegate flows enough.

Sharif@Forged

iTrader: (92)

LOL....Jermaine...hope you saw this. And I will be tuning his TN car with the UTEC.

JETPILOT

iTrader: (51)

Kcobean allready did this. The spring didn't change anything. If the gate is maxed out in flow then what weight spring you have installed makes no difference. The gate will be open 100% and boost will rise with RPM.

I will change the springs just to be sure.

Sharif make sure you have sent a nice Christmas card EARLY to this gentleman this year......

Just think Jermaine... I can post how all my problems were solved with the UTEC. Even cured my lazy eye....

Respect
JET

MIAPLAYA

iTrader: (3)

Kelly is car is not like yours. Trust me when I tell you Kelly's car has not acted normally from the beginning. Unlike your car he was getting 11 PSI but was still running 9:1 AFRs even at that boost level. Figure that one out... I'm just saying you may be able to save money by just trying a lower psi spring and seeing what you get. D35010 is making 450 RWHP with this gate and using the UTEC and his boost has been stable.

EDIT: In the end its your decision and if you want to switch to a Tial its up to you. I'm just trying to save you some money here. Turbonetics says that gate will hold up to 500 HP. http://www.turboneticsinc.com/valves_gateoverview.htm

JETPILOT

iTrader: (51)

Exhaust seems to be the factor here.... what exhaust is he running?

BTW that is 500 FLYWHEEL horespower... correct?

Yeah I will definetly change the spring first. I shouldn't assume I have the same problem as Kelly off the bat.

Respect
JET

MIAPLAYA

iTrader: (3)

I believe so on the hp part. Altough in testing it appears to flow better then that. As for the exhaust there are two people and two people ONLY who have had 11 PSI of boost AND AFRs in the 9s. Both just happen to be running the modified Greddy Evo2 exhaust. Matter of fact the second guys shop copied Kelly's design. Call Reggie and I'm sure he can send you a lower PSI spring for free.

JETPILOT

iTrader: (51)

Just a word to anyone reading this thread. This is not a problem with the TN kit. The kit is extremely well designed, and there are no isues when using as per the design. The problem here is that i have changed a part that TN couldnlt possibly have factored in in their design. TN is not responsible for this problem, and is my own doing.

TN is still willing to help me figure out this problem. It is totally their right to say sorry... "your on your own." but they didn't.

Thanks reggie @ turbonetics. Big thumbs up bro!!!!

One more reason the buy TN.... when you f*ck something up... they are still there to help idiots like me.

Respect (For Turbonetics)
JET

MIAPLAYA

iTrader: (3)

Thank you for that Jet. Rarely do people post something like that and trust me when I tell you that I and they appreciate it.