I bet you are running out of pump. You still use a MAS right? If you have a boost leak, you would be running much richer than before and your A/F ratios are leaning out. I would pony up the $95 for a 255lph walboro.

A metal bushing set and a smaller shifter knob improves the feel a lot; it's very cheap to do as well.

I believe it is 225mm. The 4G63 N/T used a 215mm disk and the 1.8 was even smaller.

I doubt that a t28 will get into the 12's at this altitude.The fact that the exhaust side is so small makes the turbo run out of steam very quickly.

Any boost leak under vacuum will allow air to enter the motor that is not metered. This would definately cause the engine to run lean under vacuum and rich under boost.

Just make sure not to remove too much material in fron of the wastegate flapper because that will cause turbulance for the exhaust spinning the turbine. Porting the housing is great, but too much in front of the flapper will just cause the exhaust to be directed at the WG instead of efficiently...

The knock sensor is a peizoelectric crystal that produces a voltage when it is deflected. Sound is vibration, haven't you heard that atmosphere track?:) When the fuel pre-ignites before the spark goes off, the pressure spike in the cylinder shakes the block and the voltage signal produced by the...

Depnding on how the air is metered, not much adjustment may be necessary. With a MAS, it will regognize the increase in airflow and the ECU will automatically add more fuel. With a speed density set up, so much more is being flowed at any given boost/RPM and would definately require a new tune...

Why would the runner furthest from the throttle body see more airflow? The #1 cylinder is on the driver's side.

Is this Jack in C/S? I've heard he does great work and I have yet to hear of one of his motors walking. He built my friends FWD tranny with upgraded syncros and shift forks for under $600 and that thing shifts like butter.

That compression is great becaue it doesn't vary from cylinder to cylinder.Get the t28, as long as it is tuned correctly your motor will last.

I bet the boost leak is causing a very rich condition at high boost resulting in a misfire which would read as lean on a wideband from all of the uburned oxygen.What is the A/F ratio as the car is spooling?

I don't understand why 30% and 80% are the manditory settings for the AFC.Every car is different and needs unique settings for the most part. The RRE SAFC article that says to set it at 30/80 is like 8 years old.For instance, I was seeing lots of part-throttle knock a while back. My High...

^^^What kind of a comment is that, wret? jtmcinder is right, it matters where in the wheel the weight is removed.Power is change in energy with respect to time. The energy of a rotating object is dependant on inertia, which for any given mass and diameter of a wheel can change depending on...

B,C, and A wheels have uniform blade spacing while the G's are doubled. That is definately a 13G.

Just to clear things up a bit; airflow is already air/time. Airflow is a mass or volume of air changing over time.Airflow/time would be the rate at which the airflow is increasing with respect to time.

Heat exchanger technology is actually pretty intense. There is an Australian company that specializes in heat exchangers and has a very comprehensive explaination of the differences between good and bad heat exchangers. Does anyone know what I'm talking about?Anyway, there is a big...

Try logging just RPM, knock, and timing advance.

How many variables are you logging? My Palm105 logs about 55 samples per second. Obviously this means if I look at 5 variables, It logs each one 11 times per second.Is the knock any better at 12.5:1? Is the timing more advanced as you lean it out?I'm still convinced that 70+% duty cycles...

You need to lean it out (even if the timing is that advanced). 73% duty cycle at 3400RPM is way more fuel that your injectors can even deliver at higher RPMs. I bet the knock is from too much fuel and the timing is not the direct cause. Seriously 550's must be squirting a lot of gas at that...

I assume he has a datalogger simply because he can see fuel trims.Since this is a 2G, you must tune WOT using timing advance on a 2G when using a logger. I belive the fuel trims do not affect WOT fuel delivery or timing control.I have never had a 2G, but I know that timing falls at the...

After searching around a little more, I realize that t-25 owners have hit over 20lb/min, but all at the boost level the post starter is running.

A t-25 would never be able to flow that much. That is well over 300CFM.Not amazing numbers, but good for 220-240WHP.

I think the yellow top is a deep cycle battery. Any short period of time with the starter drawing current could ruin it. The red-top is the auto battery made for large current draws. Deep cycle batteries are great because you can charge them and discharge them a million times without ruining the...

It is like trying to compare compressors by the trim, it is just a ratio. For example a T4 60trim flows 60lb/min where as a T3 60trim is the size of a T28.

I was wondering the same. My hood is already black because of extreme fading and the spoiler is almost as bad as the hood was.I also have a red 1GB, I think a black spoiler woud look good considering the whole hatch and roof are black.

Doesn't the GVR4 have a taller 1st?

FYI. wastegates are not supposed to see vacuum, it shortens the life of the diaphram. That is why every single OEM turbo has a boost source right off the compressor housing or LICP.

The ABS computer is grounded when the logger is plugged in, so don't worry if you have ABS and the light comes on. FYI, the ABS does not work with the logger plugged in.

The red goes on the upper left metal terminal. The two black wires go on the right, one all the way on the bottom and one third up from the bottom.

That to me looks like a T3 60 trim, it is about as big as a T28.

The jerking might be from being way too rich off idle. Put the AFC back to 0% at 1000RPM and re-set the ECU by pulling the negative battery terminal. You want the trim as close to 100% as possible, so your trim rising when you take away fuel is exactly what it should be doing.The reason...

Mine opens at .55 bar, just about 8psi.

The BCS can't make the boost go lower than the spring pressure. If it is opening, it effectively acts as a bleeder valve and allows a few more psi before the WG sees spring pressure.

Seriosly, Amsoil is the best for the money. I just tried the GL4 75/90 and it is unbelievable. My 153K old transmission can shift into second after taking 1st to the top like butter.

Please, just post RPM, Knock, Timing, and maybew O2. That is too hard to read.

The 550's add about the same amount of fuel that the 2G MAS takes away from reading a lower frequency. The corrections on the AFC will not be very drastic.I would make sure the knock sensor is in tight, a loose sensor will read knock all day.Also, check for post MAS pre turbo leaks, for...

The best tranny oil I have found is one quart Penzoil and the rest with Amsoil 75/90 GL5.The Amsoil is by far the best gear lube out there, the stuff never breaks down and protects well in all temperature ranges. The quart of Penzoil helps combat the "slipperyness" of the GL5 and allows the...

Add fuel immediately, the 2G MAS reads a lower frequency for any given RPM compared to the 1G MAS. Add about 10% across the board and re-set the ECU, for I'm sure all your fuel trims are maxed out.

It's just the damn KE transfer. Look at my previous posts.

Re-read my above post before reading this if you have not already.I have worked out the algebra in the previous post and have concluded that the arguments are all in the same.Sure, you can say that higher pre-turbine temp increases the force on the turbine...temp is simply avereage...

I think you make this too complicated to present your idea.First of all, pressure is only slightly related to volume. The definition of pressure is not P=nRT/V...it is Force/area. PV=nRT is a relationship most gases in most situations abide by.Work equals the line integral of Force*dR...

I don't quite understand your last post, but I discourage not having a vaccum "pulling" pressure out of the crankcase.It's sipmle; the blowby is removed from the crankcase easier when there is a vacuum pulling it out.The PCV is useless under boost and the intake pipe has the most vacuum...

I am not a regular poster, but I'd lke to share my opinion.First, Oldman is awesome for taking the time to explain all this.Here's how I think about it: -The crankcase always needs to vent blow-by -The PCV is the main exit for pressure at idle because it has a vacuum behind it -The...

The heater wires are unnecessary, the car's exhuast will sufficiently heat up the sensor within 30 seconds of idling, especially on a turbo car where the post-turbine exhaust velocity is pretty slow and hot.All brands have different colors of wires, for instance my Bosch was white on the...

I bought another DSM, a '92 AWD read Talon. I think the 14b is going, but it still makes full boost at about 2800-3300 depending on gear and altitude but it smokes like a mo fo.It smokes a lot, especially under boost. This is why I thought it could be the turbo. I don't think compression is...

The Hallman comes with a "heavy" spring in the box, just look for it.

Turbo laser is a dumbass.I have one of the smallest 50trim combos (TO4B and 69trim turbine) and it flows WAY more than any 16g. It is a 48lb/min compressor.THe evo flows upwards of 590CFM, even the big 16g flows 550.Think about the 62-1 TO4S turbos, that could be a T3/T4 set up and...

I can buy Toulene in a pure form at my local hardware store. It is around 9-10$ per gallon. It works extremely well in 10-30% tolulene:gas ratios.

Total, just think about it for a second. Having the WG source before the TB is simply a bad idea. When you are at part throttle, the pressure in the pipes is much higher then that of the intake mani. If your boost gauge is reading 5psi, then the pressure in the pipes is likely over 10psi because...