Rims, BOV's and Boost

[BDub13]

I am looking at some new rims and tires or my 93 TT 300. Just wanted some opinions from other people who are speaking from experience because I font want to regret my choices. I was thinking 18x9.5 on the front, and 18x11 or 12 on the rear. I want a 25 or 30 sidewalk on the tires, but I am unsure what widths will fit on those tire sizes. I also would like some help with offsets so that the wheels will be flush with the fender wells, but not rub when I hit some bumps. It is currently lowered by 1.5 inches all around.

Just another quick question, I have heard that replacing the intake pipes with hard pipes causes a sensor (I think it is the MAF) to vibrate and send inacurate data leading to a bad idle. Is this true? I was wondering because I was looking at some BOV's and I think those only work on hard pipes? I want them just because they will help things run smoother and sound awsome. I have always been confused by BOV's Vs. Wastegates, so if someone doesn't mind giving an in depth description. Do they both make the same cool sound??

I was also curios as to how they get the horsepower rating from the factory. I mean, how much boost are they running to get the numbers they do? Are all turbo'd cars tested at the same boost so that they are comparable or what?
How much boost is a safe maximum on a stock VG30DETT?

Thanks for any answers u can give, I would really love some answers.

[vulcanrush]

tt.net is a great place to search for more information.
as far as boost, stock boost from the factory is 9psi, i believe?
also, how much boost you can run depends on a lot of factors, the fuel (100 octane vs 93 octane, etc.), your supporting modifications (intercoolers, exhausts).
please search, you can find a lot of great information.

[DudeZ]

vulcan rush... http://www.tt.net/ ?? is that the website? its just about internet services

[Ba11erz]

vulcan rush... http://www.tt.net/ ?? is that the website? its just about internet services

@DudeZ tt.net is abbreviated for www.TwinTurbo.NET.

That's the official website for all the TwinTurbo gearheads, enthusiasts, and the like.

[DudeZ]

vulcan rush... http://www.tt.net/ ?? is that the website? its just about internet services

@DudeZ tt.net is abbreviated for http://www.TwinTurbo.NET.

That's the official website for all the TwinTurbo gearheads, enthusiasts, and the like.

ahh cool. thanks! ill go check it out right now.

[BigTDogg (MA)]

There's also a sticky at the top of the Z32 General forum about wheel fit Though it was lifted from a TT.net FAQ, LOL. FFPWNER is right, Wheels, not rimz yo!

To the OP, you can install your BOVs in the stock recirculation valve locations, under the headlights. Hardpipes are fine for the car, no issues other than being harder to install, remove.

Wastegates are on the turbo themselves. They are preset to a certain boost pressure. When the actuator senses that pressure, they open, diverting exhaust gases around the turbine wheel, thus controlling the boost level.

Recirculation valves, or blow off valves vent the compressed air from the turbo when you let off the throttle. When the throttle bodies close, the turbo is still boosting. If you close the throttle body, this boost has nowhere to go except back to the compressor wheel. This "compressor surge" as it's called, can shock the compressor wheel and damage the turbo. Recirculation valves send the boosted air back to the intake side, and are the best choice for a MAF regulated system. BOVs make a cool pssshh sound when they vent the air to atmosphere, creating a temporary rich condition.

[marty1mc]

I am looking at some new rims and tires or my 93 TT 300. Just wanted some opinions from other people who are speaking from experience because I font want to regret my choices. I was thinking 18x9.5 on the front, and 18x11 or 12 on the rear. I want a 25 or 30 sidewalk on the tires, but I am unsure what widths will fit on those tire sizes. I also would like some help with offsets so that the wheels will be flush with the fender wells, but not rub when I hit some bumps. It is currently lowered by 1.5 inches all around.

Just another quick question, I have heard that replacing the intake pipes with hard pipes causes a sensor (I think it is the MAF) to vibrate and send inacurate data leading to a bad idle. Is this true? I was wondering because I was looking at some BOV's and I think those only work on hard pipes? I want them just because they will help things run smoother and sound awsome. I have always been confused by BOV's Vs. Wastegates, so if someone doesn't mind giving an in depth description. Do they both make the same cool sound??

I was also curios as to how they get the horsepower rating from the factory. I mean, how much boost are they running to get the numbers they do? Are all turbo'd cars tested at the same boost so that they are comparable or what?
How much boost is a safe maximum on a stock VG30DETT?

Thanks for any answers u can give, I would really love some answers.

I think 11 or 12 inch wheels in the rear may be too much without rolling and pulling the fenders and maybe some negative camber. The front should be fine depending on offset. If you search around, you will find the answer.
I have never seen where hard pipes on the motor cause the MAF to vibrate. Both are isolated from each other.

On BOV's - you are actually better off without BOV's and keeping the stock recircs. The BOV's let air out of the system (unless you have the recirc kit) the MAF has reported. Some have had issues when they shift due to this, some haven't. But, you don't need hard pipes for this, you can put them in place of your stock recircs.

BOV's and Wastegates perform different functions. Wastegates open to allow excess exhaust pressure to release in order to manage the boost levels of the turbo. BOV's open to release excess intake pressure to keep from "compressor surge" when the intake air is highly pressurized and causes back pressure on the compressor side of the turbo. This usually happens when you shift of let off the gas and the intake stops accepting air. That pressure has nowhere to go unless the recirc valve or BOV releases it.

Hope this helps.

Also, TT.net is a great site, but you better search thoroughly BEFORE you post. They will rip you a new one if you don't. You should always search first anyway. But, I took mercy on you

[BigTDogg (MA)]

I think 11 or 12 inch wheels in the rear may be too much without rolling and pulling the fenders and maybe some negative camber. The front should be fine depending on offset. If you search around, you will find the answer.

Also, TT.net is a great site, but you better search thoroughly BEFORE you post. They will rip you a new one if you don't. You should always search first anyway. But, I took mercy on you

I knew someone else would answer as I edited to address the OP, lol

Oh, and marty is 100% correct on TT.net. Tons of info, but definitely search first, because every question you've asked HAS been asked before. Might also want to check out howstuffworks.com to get a general understanding of turbochargers.

Oh yeah, the TTZ OEM boost is 9PSI. Every other turbo car manufacturer has their own boost levels

[BDub13]

So, from the information u guys have given me, I think I would like to stick with the recircs instead of the BOV's, but the sound they make is so awsome! Do wastegayes make the same noise?

[BigTDogg (MA)]

So, from the information u guys have given me, I think I would like to stick with the recircs instead of the BOV's, but the sound they make is so awsome! Do wastegayes make the same noise?

Open wastegate dump pipes make an even cooler noise, but you'll need to get a TD-05 kit or some other externally wastegated turbo, a $5k+ project.

Stock recircs will handle pretty much any power level. If you want sound, get a full turbo back exhaust with no cats, and a Selin dual intake. Then you'll hear spool up and decel, especially in tunnels

[A Paratroopers 300zx]

So, from the information u guys have given me, I think I would like to stick with the recircs instead of the BOV's, but the sound they make is so awsome! Do wastegayes make the same noise?

Also, another option would be to go with BOV's such as the HKS SSQV set and get the recirc kit with it so you then can have that distinct sound you're looking for whenever you want... within 15 minutes of turning your wrench.

[BigTDogg (MA)]

So, from the information u guys have given me, I think I would like to stick with the recircs instead of the BOV's, but the sound they make is so awsome! Do wastegayes make the same noise?

Also, another option would be to go with BOV's such as the HKS SSQV set and get the recirc kit with it so you then can have that distinct sound you're looking for whenever you want... within 15 minutes of turning your wrench.

True, best of both worlds.