JeffTsai

iTrader: (1)

Ok, I'm doing this as a favor anyone that is interested in boosting their cars. Mods if you can, please keep this in the general 2GS section instead of performance(because most people rarely stray into that sub section) and possibly sticky it in the future when we get several pages of useful info.

If you have a question feel free to ask it and I'll do my best to answer it

Here's my DIY website for various things on the GS. I update it when I have extra time, which unfortunately is not so often.
http://www.ProjectGS.com/DIY

chrispy

iTrader: (21)

Thanks Jeff, some people here make a thread for every single question they have.

JeffTsai

iTrader: (1)

I'll start off by doing a few writeups here. If you need any clarification just ask. I will be adding to this thread whenever I have extra time.

What are the basics of a turbo setup? What do all those fancy parts do and how does it all work?
A: This will be long...I'll elaborate later

Q: What is a reasonable power goal on the stock GS300 engine?
A: If you stay on stock compression and stock fuel system, I would suggest around 7psi and no more than 9psi. At that boost level you will make approximately 275-290whp. You will be able to run around 15-18psi If you change the headgasket to a thicker one to lower the compression. It will put you around the 375-450rwhp range depending on your setup. The fuel system will also have to be upgraded because the stock stuff can't supply that much fuel. Also, keep in mind the transmission will be nearing the danger zone at this point. For long term reliability, plan for upgrades to the transmission if you plan to run at 400rwhp or higher.

Q: What kind of fuel system upgrades do I need to do for 15-18psi boost and 400rwhp?
A: First of all you will need to upgrade the fuel pump to a higher flowing one. A popular choice is the Walbro 255lph pump. For this car you will need the GSS342 specifically. Then you need to upgrade the fuel injectors to something bigger. To the best of my knowledge, the stock injectors are around 280cc. A good rule of thumb for the 2JZ is that each CC of injector will support roughly 1rwhp. A good injector size to use is a set of 440cc or 550cc injectors. When you buy injectors make sure they are high impedance saturated injectors and not low impedance peak and hold units.

If you want power to be around 350-400rwhp then you can just barely get away with just a walbro fuel pump and 440cc injectors. Note I said barely because it will be at the limits. The reason is because the factory fuel pressure regulator supplies 43psi of fuel pressure to the injectors. When you have 15psi of boost from the turbo pushing back against the injectors, the effective pressure of the injector drops down to 28psi. To counter this problem, people install a return fuel system which allows them to run a aftermarket fuel pressure regulator.

The most popular one used in the 2JZ crowd is the Aeromotive A1000 EFI or A1000-6 EFI, these have a rising rate 1:1 ratio. This means every pound of boost you make, the regulator will increase fuel pressure by an equal amount. So if base pressure is 43psi at idle, when the turbo boosts 15psi the fuel pressure will be at 58psi. Factor in the turbo pushing back on the injectors and your effective pressure will be back at 43psi. Some people crank the base pressure way up from 43psi to get more flow out of the injectors. There are upsides and downsides to doing that.

When you raise the pressure on the whole system, it puts more stress on the fuel pump and injectors. Running the fuel pump at excessive pressures for a long time will shorten its lifespan. Running the fuel injectors at too high of a fuel pressure will cause the solenoid to stick. The phenomenon where there is so much fuel pressure, the fuel injector has a hard time keeping the pintle closed.

I can go into more detail about everything here, but it will take a lot longer to write up. Again if you need any clarification on anything, feel free to ask.

JeffTsai

iTrader: (1)

Q: What kind of transmission upgrades should I do?
A: It really depends on your power level. I suggest anyone with over 300rwhp to get a transmission cooler as the ABSOLUTE minimum. In my car I run two fairly large transmission coolers. I can attest to the strength of the stock transmission as long as you keep everything nice and cool. I put about 25psi of boost(around 550-575rwhp) through the bone stock GS300 transmission. It did not like it very much, but it holds the power if you let off between shifts.

There are also varying levels of transmission upgrades available. It really all comes down to how much you want to

This post is going to be long, no time to finish it right now...I'll elaborate more later

Q: What can I cheap out on, I'm really broke?
A: Well, if you're that strapped for cash I really advise against boosting the car. This is not a cheap car to get going fast, but it is extremly fun once it's fast. Ok, if you want to cheap out on stuff I would say you can pick up an ebay turbo manifold and ebay intercooler.

You can also buy the aluminum intercooler piping from ebay, piping is piping no matter where you get it. Keep in mind the piping kit you buy on ebay is just a whole bunch of randomly cut and mandrel bent universal piping. You will still have to custom fabricate all of your intercooler piping or pay someone to do it.

You can also get a knock off blow off valve, most of them work well. Now, for the turbo and wastegate I would not cheap out on and stuff I suggest you buy name brands for those.

If you decide to boost the car keep a few things in mind before you do it. Yes it's going to be fun but is it going to worth these hassles?
- Fuel economy is obviously going to be worse.
- It may be more difficult depending on your state to get your car inspected due to emissions.
- Tinkering here and there will be required every once in a while.
- One other rule of thumb...MAKE SURE you have at least $1-2k set aside incase something breaks, especially if this is going to be your only mode of transportation. If you have an extra car then this won't be such a big issue.

BLAZE

iTrader: (2)

Great info, I think I am going to have to bring you my gs4, so u can fab me a turbo kit for that. Low boost would be fine

fordsvtmfl

iTrader: (13)

ok jeff...get ready lol *1998 Gs300
here is my setup (already bought, wating for in the mail)
(i will be running 8.7 psi off the wastegate)
Turbonetics T62-1
Apexi Neo
Function7 Oil Flanges
generic intercooler
OBX wastegate with 8.7 psi spring
Blitz BOV
other misc stuff...
ok here are my questions i desperately need answered..lol
1. What wiring diagram do i use when installing the NEO?
2. What is the ratio of psi to fuel (when tuning...how much fuel do i add per psi?)
3. Will i get a check engine light? (will o2 sims fix this?/do i need them?)
4. What do i set my BOV at?
5. Do i need a turbo timer for everyday driving? and if i know my oil temp..what is to high? (high enough that i would need to let it idle for a few min)
6. What is with this re-learning thing ive read about? (it was discussed in jeff's original turbo build thread) what will i need to do to compensate?
7. Is there anything else critical i am missing?
Sorry for the length, but any info would be greatly appreciated!!!
Thanks

dxb_8788

thanks 4 the info

MrExecutiv

iTrader: (2)

thanks Jeff, this is gonna be very helpful.

JeffTsai

iTrader: (1)

First of all I would suggest dumping the Apexi Neo. It's not a very good piggy back for this car. It works great on other cars, but just not on the GS.

1. Wiring diagram refer to my DIY website listed on the first post of this entire thread.

2. There is no golden number because every car will react slightly differently. I would suggest doing a linear increase. If you're on the factory fuel system then you want 7psi of boost to be around 30% fuel increase. Please verify with a wideband sensor that your air fuel mix is good before doing a extended pull.

3. With the Neo you will throw a CEL. I suggest you getting an AEM FIC or Greddy Emanage ultimate. Both of those units have a function called O2 skew. Basically it tricks the stock ecu into thinking all the readings are correct and you won't throw a CEL. The O2 skew function is for the primary O2 sensors before the cat. This is different than a O2 simulator. The O2 sim modifies the signal for the sensors after the catalytic converters. The use of a O2 sim is so you can remove the cats and prevent the CEL from showing up.

4. Every BOV is different. The way to adjust it really depends on how it's designed. I have a HKS SSQV on my car and it requires no adjustment at all. The Tial BOV you have to replace the bov spring to what your boost level is. There is a preload screw on most BOV's so you can dial it in to where you want. For yours you just have to adjust it until you get no more turbo flutter at low boost, and not so tight to where the bov doesn't vent correctly at high boost or leak out. It pretty much comes down to fine tuning it.

5. A turbo timer is nice, and I usually activate mine if I just had a spirited drive. If you run the car hard, it's not a good idea to shut it off right away because the oil will solidify in the turbo. Once you do that too many times the lubrication passages in the turbo get smaller and smaller and will eventually become completely clogged. Analogy: just like a heart attack, but oil is to a turbo oil like blood to is a heart.

Let it idle at least 2-3minutes to cool down right after a spirited drive. If you were driving extremely hard going ***** out to the wall then let it cool down for 5 minutes or so. Another trick is to just cruise granny style before you get to wherever you need to be. Typically I just cruise slow when I'm 1-2 miles away from where I need to be then I can just shut it off right after I park the car. Also, most aftermarket remote start alarms have turbo timer functions built in(I have the Autopage RS-1000 and it has that function). I usually still turbo time it for 30sec anyway just because it looks cool

6. The ECU in this car is highly adaptive and tries to adjust everything as close to perfect operating condition as possible. It's great because it is extremely good at doing it. The downside is that you don't want to be running factory tune under boost because it is WAY too lean and you will destroy the motor with the factory tune. What happens much of the time is that you will tune the car and everything will be peachy for about 50-100 miles. Then all of a sudden out of nowhere the tune will start going out of whack and you will have to retune it. That's why I suggested using the AEM FIC or Greddy emanage ultimate. They have the O2 skew function that tricks the factory ECU into thinking everything is working properly. That way the stock ecu won't keep fighting your tune. Without the O2 skew, you tune will keep getting messed up.

Anything critical...well it's an awesome learning experience. For me I've only been working on cars seriously for the past 2 years, and speaking humbly...I think I'm pretty decent at it now . For me, there was really nobody that could give a guiding or helping hand. I believe I was the first DIY NA-T pioneer here on CL. I pretty much had to figure out most of it by myself. I guess that's one of the reasons why I learned so much, because when you have nobody else to help you out...you have to learn and know everything and how it all works. Late nights of research and many nights spent in the garage is pretty much how I've spent most of the last year of my life. Don't even have money/time for a girlfriend lol

If anyone has questions, please read through this entire thread first. If you still don't find what you need to know, feel free to ask and I can be your guide.

fordsvtmfl

iTrader: (13)

Jeff, you are the man! thank you so much! and yea i learned last night i need to dump the neo...and get the FIC i think i can get the place i bought it from to cancel the order before it ships..(cross fingers)
thanks man

jwin

iTrader: (16)

I am planning on doing a 2jz-gte swap as my motor has around 200000 miles on it. Do you know exactly what wires i would need to keep and or extend for the motor swap. Is it as simply as a plug and play operation .How much power will the aristo ecu with AEM FIC take before i have to go standalone

jwin

iTrader: (16)

Great write up btw

fordsvtmfl

iTrader: (13)

2. There is no golden number because every car will react slightly differently. I would suggest doing a linear increase. If you're on the factory fuel system then you want 7psi of boost to be around 30% fuel increase. Please verify with a wideband sensor that your air fuel mix is good before doing a extended pull.

just checking..but you did mean 30% at 7psi and not 9 right? and if that is true that would be about 4.3 fuel per lb of boost (all things being equal) and about 38%-40% at 9psi? that sound right? (two diff ppl have told me 11.5 at full throttle at 9psi...what do you think of that estimate?
Thanks

jwin

iTrader: (16)

A1000-6 EFI Fuel Regulator is the one with the By-Pass better than the one without. What part-number exactly if you know off the top of your head. Thanks Jeff

mtparker18

Also, if you want the most complete kit (and you have the money ) Get the Swift Racing kit. I've hurd a lot of good things about it and its suspost to have a big gain with it.




Also ebay kits, their no good







Jeff, you should also make a thread for Q&A's for swaps