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Discussion Starter · #1 ·
I just installed a KO Racing SB 50 trim turbo. I also hooked up an EGT gauge in my #3 runner. On KO Racing's site it says you can run 16-17 psi with no fuel mods. Would you guys set a limit on your EGT gauge or keep the boost down? And what temp or boost would you run? I don't want to ruin my 94T with 42K on it. It's going to be another year or so before I get fuel and an EMS and want to be safe with my new turbo but want the best performance possible. Any suggestions?
 

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get on a dyno, start at 11psi, check your fuel A/F, then slowly up the boost and see if your safe... 275rwhp is the stock fuel limit, but i would watch the fuel more than the hp
 

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^^^Follow his advice^^^. EGT is just a possible indicator of safety, not a be all and end all. Do NOT rely on it to set any parameters, rather watch it as a sign something is not right and back off if they go to high. You're going to see the highest EGTs on long pulls under boost (like drivign up a long hill!)
 

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And remember to leave allowance for varying operating conditions like on cool days you will have even higher boost, or if you get some bad gas.
 

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two94gte's said:
I just installed a KO Racing SB 50 trim turbo. I also hooked up an EGT gauge in my #3 runner. On KO Racing's site it says you can run 16-17 psi with no fuel mods. Would you guys set a limit on your EGT gauge or keep the boost down? And what temp or boost would you run? I don't want to ruin my 94T with 42K on it. It's going to be another year or so before I get fuel and an EMS and want to be safe with my new turbo but want the best performance possible. Any suggestions?
That recommendation is for a 46-trim SB. I suggest you get rid of the boost controller and run only a single line to the bottom end of the wastegate so that you only go to the spring pressure. Set up a BillWOT FCD and set it to fuel cut you at 14psi. If you happen to hit fuel cut at higher RPMs, live with it. If you do this, you have a very high probability of keeping your engine safe until you can upgrade your fuel system and engine management.
 

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Discussion Starter · #6 ·
RickyB said:
That recommendation is for a 46-trim SB. I suggest you get rid of the boost controller and run only a single line to the bottom end of the wastegate so that you only go to the spring pressure. Set up a BillWOT FCD and set it to fuel cut you at 14psi. If you happen to hit fuel cut at higher RPMs, live with it. If you do this, you have a very high probability of keeping your engine safe until you can upgrade your fuel system and engine management.
In 1994 Toyota raised the fuel cut to 15-16 psi. If I turn off my EBC, will I boost to 15 psi with my SB. On the stock peashooter I couldn't. Does this also mean that 14 psi is the upper limit on stock fuel with this turbo. I also have a Spearco IC FWIW.
 

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if you turn off your EBC, you will boost to what the spring is inside the WG... you should have that on a receipt of the WG
 

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dyno the car and see where you are at, then decide where the safe spot is for boost limit.... the dyno never lies.
 

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7THSIGN said:
dyno the car and see where you are at, then decide where the safe spot is for boost limit.... the dyno never lies.
The dyno does not put the same amount of load on the engine as the road. Neither does the dyno generally allow you to test the engine at the lowest air temperatures it will run outdoors. Neither are most of the wideband sensors at most places all that accurate--especially the ones that insert a tube into the tailpipe.

You can drop your fuel cut down by swapping your turbo pressure sensor to a 91 model, since that is all that changed to raise the limit. That should get your fuel cut limit what to around 12psi and you can use a billwot FCD to set it up to 14.

Also, the spring rate on the SB and your actual boost will vary depending on many factors such as how much pressure drop you get across your IC/IC pipes, what altitude you are driving at and how much boost creep you get.
 

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Discussion Starter · #11 ·
Could I set my boost gauge warning to 13 psi and be safe without swapping my turbo pressure sensor and setting up a FCD at 14 psi. And what kind of EGT's will I be looking at. Are there any numbers that you should never exceed? I just want to set my EGT warning at something and right know I have no clue what temps I'll be looking at. My gauge is in F.
 

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two94gte's said:
Could I set my boost gauge warning to 13 psi and be safe without swapping my turbo pressure sensor and setting up a FCD at 14 psi.
That does not protect you against all boost controller failures. What if something physically restricts your wastegate from opening? True fuel cut is the best protection against more turbo than the fuel system can manage.

Keep in mind that this is your car. Do whatever you wish. My opinion short of actually putting a wideband and duty cycle measurement device on your car and running some experiments is that you keep it at 14psi and under near redline.
 

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A bit OT, but would you please post the part number on your 94 pressure sensor?
Thanks,
 

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Unless you specified a higher boost pressure WG when you ordered your turbo kit, they all get a .7bar (about 10psi) wastegate. If you are seeing 15psi, then there is something wrong with your system. try running just a line from the wg to the turbo and leaving the top vented to atmosphere and see how it acts. Does it start lower and go up to 15? Or does it go straight to 15 once it spools?

You never want to exceed 1500degF if possible, and if you see it shooting past 1500deg, get out of it.

Also, Ricky is right, the 16-17psi that we say you should be safe at is for the 46trim, the 50 trim is more like 14psi -- and in all cases, I highly recommend verifying your A/F ratio with a wideband o2 sensor to ensure you aren't going lean on the top end.
 

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Discussion Starter · #15 ·
The 15 psi I was running was on my stock turbo with my EBC. I have not seen 15 psi on my SB because I just installed it and have not had a chance to drive it yet. As for a part number on my turbo pressure sensor, I'll be home tomorrow and post that for you.
 

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Thanks. I thought I read somewhere the pre-94's had that part number and was concerned someone had swapped mine out.
 

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Discussion Starter · #18 ·
RedTuna said:
Thanks. I thought I read somewhere the pre-94's had that part number and was concerned someone had swapped mine out.
Do you know if the pre-94's are the same part number? And if so, then why is the 94-95 fuel cut higher than 91-93?
 

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I was wondering the same thing.
 
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