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411 HP GSXR / 203 HP Vrod
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Discussion Starter #1
Is there a cheaper fix to raise the rev limit on the Auto Supra than the G-Force Computer? Also, who has the G-Force in stock?
 
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I don't know much about the rev limiter, I would think you can push it out to 8,200, but I have no idea, you have to find out, and about having G force in stock, you must send ur stock ecu out for them to reprogram it. Then you'll get it back w/ all the goodies, should break down and get the stage 2 G force ECU upgrade for the 2jz.

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You have to send in your ECU for the upgrade. They solder on a motherboard with the gforce chips. There is, unfortunately, no other way to raise the rev limiter, save standalone engine management. I recommend leaving your ignition and fuel curves stock, and using piggyback computers to fine tune those.
 

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Hey darren, I hear that if you upgrade to 850 cc injectors (from 720's) you want Gforce to take out approximately 15% fuel across the board or else the car will be runnin way rich and it's hard to take out that much fuel with piggybacks... What do you think?
Also, what RPM should i raise my rev limiter too if i'm on stock motor (stock springs/valves)?

Walser said:
You have to send in your ECU for the upgrade. They solder on a motherboard with the gforce chips. There is, unfortunately, no other way to raise the rev limiter, save standalone engine management. I recommend leaving your ignition and fuel curves stock, and using piggyback computers to fine tune those.
 

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houstonT said:
Hey darren, I hear that if you upgrade to 850 cc injectors (from 720's) you want Gforce to take out approximately 15% fuel across the board or else the car will be runnin way rich and it's hard to take out that much fuel with piggybacks... What do you think?
Also, what RPM should i raise my rev limiter too if i'm on stock motor (stock springs/valves)?

I have my limiter set at 8000 rpm and that seems to work fine on the stock motor and valve train. The motor can handle that with no problem although it does stress the accessories (AC, power steering, alternator, etc). I shift at 7300 to 7500 at WOT.
 

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Thanks supratt96, do you have any info about the fuel maps and such? What fuel system you have?

supratt96 said:


I have my limiter set at 8000 rpm and that seems to work fine on the stock motor and valve train. The motor can handle that with no problem although it does stress the accessories (AC, power steering, alternator, etc). I shift at 7300 to 7500 at WOT.
 
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What I want know is if you set your rev limiter to 8000rpm, do you also set your shift point for an auto? Did you set your shift point at 7300rpm or is that just where it shifts.
 

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houstonT said:
Thanks supratt96, do you have any info about the fuel maps and such? What fuel system you have?

When I got my ECU modified by G-Force, they did the timing and fuel maps for BPU. The car ran awesome in every way and was able to run mid 11s with 119 mph trap speeds.

When I converted to single I was gonig to get the ECU re-done. But the car ran so good with the same ECU that I left it alone. No problem with running excessively rich with larger injectors as someone else had mentioned.

I have a custom fuel system that was built by Altered Atmosphere. It consists of two stock pumps, -6 lines, HKS fuel rail, HKS 720 injectors, Paxton FPR and an Apexi fuel pressure gage.
 

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Supreme said:
What I want know is if you set your rev limiter to 8000rpm, do you also set your shift point for an auto? Did you set your shift point at 7300rpm or is that just where it shifts.
Thats just were it shifts. I'm not aware of any way to move the shift points up or down. Generally speaking, the more boost you run the higher the shift point gets. But on a SP trans, 7500 seems to be the highest it will go without manually shifting. On a stock motor, there is no benefit to shifting any higher than this.
 

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411 HP GSXR / 203 HP Vrod
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Discussion Starter #10
SupraTT, Paisley tells me that if I get a beefed up tranny then I don't need the G-Force Upgrade... Is this good info? I know in my heart that the Beefed up tranny is best but I just spent a small fortune with the turbo kit and 19" wheels so the funds are getting kinda tight. Hopefully I can find a happy medium. Analyze my situation and give me some advice... I'm expected to pick up my Dawg from Paisleys tomorrow and I know I'm going to have rev limit issues. Also, I have no stall or beefed up tranny as of yet. On a limited budget for now should I...
1) Just drive the car as is?
2) Get the G-Force Upgrade?
3) Get the 4K stall and tranny cooler?
4) Get the tranny, G-Force and stall? (Financially Impossible)

I have a notion that without a stall I'm going to be unhappy. Damn, I've got issues!
 

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Bad Karma Supra
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HKS T04R said:
SupraTT, Paisley tells me that if I get a beefed up tranny then I don't need the G-Force Upgrade... Is this good info? I know in my heart that the Beefed up tranny is best but I just spent a small fortune with the turbo kit and 19" wheels so the funds are getting kinda tight. Hopefully I can find a happy medium. Analyze my situation and give me some advice... I'm expected to pick up my Dawg from Paisleys tomorrow and I know I'm going to have rev limit issues. Also, I have no stall or beefed up tranny as of yet. On a limited budget for now should I...
1) Just drive the car as is?
2) Get the G-Force Upgrade?
3) Get the 4K stall and tranny cooler?
4) Get the tranny, G-Force and stall? (Financially Impossible)

I have a notion that without a stall I'm going to be unhappy. Damn, I've got issues!
Wow...this is quite a little problem you got! An upgraded tranny and G-Force have nothing in common - I'm suprised paisley told you that. If you only do one or the other..damn..

Get the G-force, the big stall and a HUGE tranny cooler to help your stock tranny live longer 'till you can afford a built one. If you keep the stock ecu - you'll bounce off the rev-limiter all the time under hard driving...not sure how much that will hurt the car...

good luck,
Jay
 

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My Rev Limiter is set at 7800 rpm and the first time I hit it, I almost shit myself, but I am comfortable with it now. My SP tranny shifts at about 6500 in first, 6750 in second, 7100 in 3rd, this is just a function of the poopy way my Boost controller is working right now (I need to re-hook it up the blitz way).

7800 is fine and probably best for most applications, however on stock turbos, you're not going to get much benefit if any from shifting higher than maybe 7000-7100 because the turbo's can't flow much air at that rpm, they just start to build alot of backpressure in the housings.

We had my car up to over 160 in 3rd gear going to rev limiter on the Dyno though. :biggrin:
 

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411 HP GSXR / 203 HP Vrod
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Discussion Starter #13
Thanks for the info Jay... I kinda knew that would be the answer but needed to hear it from someone. This is getting to be an expensive hobby and as far a money is concerned I'm almost assed out! Let's see...
1) 4,000 Sound Performance Stall = $1,200
2) B&M Tranny Cooler = $100?
3) Stall and tranny cooler install = $350
4) G-Force Computer = $800?

Damn, that's $2,500! Jesus Christ when does this shit stop?
 

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HKS T04R said:
SupraTT, Paisley tells me that if I get a beefed up tranny then I don't need the G-Force Upgrade... Is this good info? I know in my heart that the Beefed up tranny is best but I just spent a small fortune with the turbo kit and 19" wheels so the funds are getting kinda tight. Hopefully I can find a happy medium. Analyze my situation and give me some advice... I'm expected to pick up my Dawg from Paisleys tomorrow and I know I'm going to have rev limit issues. Also, I have no stall or beefed up tranny as of yet. On a limited budget for now should I...
1) Just drive the car as is?
2) Get the G-Force Upgrade?
3) Get the 4K stall and tranny cooler?
4) Get the tranny, G-Force and stall? (Financially Impossible)

I have a notion that without a stall I'm going to be unhappy. Damn, I've got issues!
Even a small single turbo will seem very laggy on the stock converter and not much fun to drive. You may or may not encounter rev limiter issues on the stock converter. However, the stock converter is the weakest link in the auto trans. It will probably not last very long on a single turbo. Mine went pretty quick even at BPU level. The stock trans itself will probably last a while if you don't drive the car too hard. A good trans cooler will help.

Here are you options:
1. Leave the trans, ECU and converter stock for now. This will of course be the least expensive route, but you will be unhappy with the driving characteristics of the car and unable to use the tremendous top end power the single turbo gives to any effective degree if in fact you start hitting the rev limiter. Kind of defeats the whole purpose of going single in the first place.

You can "drive around" this to some degree by lifting off the throttle for a moment when you hit or get near the rev limiter to allow the trans to shift (the only way it will, whether you shift manaully or leave it in drive). Down sides to this are loss of performance and continually hitting the rev limiter is not good for the engine. If you do go this route, at least put a good trans cooler on the car. This will extend the life of your trans considerably and is not very expensive (under $200).

2. Upgrade the converter, but leave trans and ECU stock. This will dramatically reduce lag and give you much better "off the line performance" making the car much more fun to drive, but will not help your rev limiter situation. In fact, it will make it worse due to the much faster rev a high stall converter allows. Going this route will definitely cause rev limiter issues. If you upgrade the converter, absolutely do the trans cooler.

3. Do the converter upgrade and the ECU together. This will be the least expensive way to go and still be able to really enjoy the car. You will shift at or near 8000 rpm at high boost. With a good cooler and regular maintenance, your trans should last a while if you don't race it too often. But you will start to notice slippage at full throttle almost right away. At low to moderate boost levels the trans should be fine.

4. Do it all at once. Obviously the best route to take if you don't want to have to worry about babying the car. It will also save on labor charges since you would only have to drop the trans once. However, it is a very expensive proposition, as I'm sure you already know.

Good luck.
 

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411 HP GSXR / 203 HP Vrod
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Discussion Starter #15
Nice response Supratt... You seem to definitely know your shit... I may buy the stall, tranny cooler and G-Force. I'll be in the doghouse with the old lady and definitely on the couch for a few nights but I'll be a bit happier with the Dawg... One more question... Would you use the .96 or .81 AR Housing with this turbo?
 

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HKS T04R said:
Nice response Supratt... You seem to definitely know your shit... I may buy the stall, tranny cooler and G-Force. I'll be in the doghouse with the old lady and definitely on the couch for a few nights but I'll be a bit happier with the Dawg... One more question... Would you use the .96 or .81 AR Housing with this turbo?
I'm not very familiar with the T04R. Is that in the same general size range as a T-66?

The largest A/R I have personally used it the .81 which I have used on both an SP-63 and an SP-66. Works great. Plenty of top end power and not too bad on lag. Since I have no direct experience on the .96, I can only give you an educated guess and say that the additional lag will probably not be worth the little bit of extra top end power.

I noticed a significant increase in lag going from a .70 to a .81, but found it to still be within my presonal range of tolerance, but just bearly. How much lag you can endure is a subjective issue. Personally, I hate lag having owned and raced big block Chevys and Fords for many years. The one thing I miss about those cars is the awesome low end torque and instant throttle response.

Remember, unless you plan on doing a lot of open road, from a roll type racing where you can use that top end power, a big turbo/AR will only make the car less fun to drive. If 1/4 mile racing, or just having a killer fast street car is your thing, you will be much happier with a small to medium size set-up.
 

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411 HP GSXR / 203 HP Vrod
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Discussion Starter #17
I believe the T04R Turbo is more equivalent to the Greddy T-78. I'm going to start with the .81 housing most likely since a .96 with no stall would be even worse. BTW, what blowoff valves are you using? I read an earlier thread that said that the Sequential HKS Blowoff sounded like crap on Auto Dawgs so I opted for 2 Blitz Blowoffs which will be mounted on either side of the Intercooler. I hope I get what I'm looking for performancewise and soundwise with the Blitz...
 
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supratt96 said:

I have used on both an SP-63 and an SP-66.

This is off-topic but I can not find anyone else that has experience with the SP-66. I am thinking about going this route and going with the SP-66 instead of the SP-63 for a little more top end power.

Would you mind briefly comparing the turbos and your experience with them? What size A/R is SP recommending for the SP-66 and in what trim? What is the lag difference and does it produce signifigantly more power? Any info is much appreciated.
 

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HKS T04R said:
I believe the T04R Turbo is more equivalent to the Greddy T-78. I'm going to start with the .81 housing most likely since a .96 with no stall would be even worse. BTW, what blowoff valves are you using? I read an earlier thread that said that the Sequential HKS Blowoff sounded like crap on Auto Dawgs so I opted for 2 Blitz Blowoffs which will be mounted on either side of the Intercooler. I hope I get what I'm looking for performancewise and soundwise with the Blitz...
That's an awefully big turbo for an auto trans car, especially with a stock converter. I fear you will find the lag to be excessive and will only be able to make any real power over 5000 rpm, and it will take the motor an agonizingly long time to wind up that high without a high stall converter. Even with a 4000 rpm stall, you are still going to encounter a lot of lag. You will probably need NOS to get it out of the hole with any authority.

Sorry to sound like a downer here, but I think you will be looking to switch to a much smaller turbo before long. A small to medium size turbo with a 4000 rmp stall can launch like a rocket. There is nothing like the feel of a 1.4 60' time. The look on some V8 guys face when you kick his ass right off the line is precious. Especially if he is one of those guys who is certain that Supras are "dogs off the line".

But, as I said before, how much lag you are willing to tolerate is a personal preference issue. You may not think it's all that bad.

Good luck with your car and let us know how it works out for you.
 
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