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undercover racing team
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Discussion Starter #1
I want to buy a 67mm turbo but I’m not sure if I have to buy injectors also I’m running 720cc injectors now with a vpc with b chip and SAFCII and I don’t want to max out the injectors I will run 30psi boost with some c16 at track and 18psi on 93octane for street... any information is greatly appreciated
 

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Boost Creep
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Your pretty much running what I am, I wouldn't run the 30PSI, I'd set it to 28PSI or so. Your VPC limited to 30PSI (I know you can bump it, but it's kind of ghetto).

You will be happy with that turbo, go DBB if you can.

I also went from a 61mm to a 67mm.
 

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Your pretty much running what I am, I wouldn't run the 30PSI, I'd set it to 28PSI or so. Your VPC limited to 30PSI (I know you can bump it, but it's kind of ghetto).

You will be happy with that turbo, go DBB if you can.

I also went from a 61mm to a 67mm.
A lot of the VPC setups will work just fine at 34 PSI or so. I've been running mine at 28-34 PSI for about 6 years now and it works fine. AFR's are just fine, etc. I did have a VPC pressure sensor crap out about 3 years ago and I bought a new one. With the new pressure sensor AFR's started getting lean as boost went above 25 PSI. I picked up a different pressure sensor from a local friend and it worked like my original -- I can run 34-35 PSI and AFR's stay just fine (in the mid-11's with all the controls on the VPC and SFC set flat (no fuel added or cut). If I run lower boost, like say 25 PSI, I have to pull some fuel with the SFC or it'll be down in the mid 10's, which is lower than I like.
 

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Moderator, l337 M0d3r4t0r
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I wouldn't say that Gadfly, I'm running 650 whp at 24 PSI... I'm sure if I jacked it a few more pounds to say 30 I'd be maxing them 720's real fast.

even 650 is close enough to what I'd feel comfortable with 720's I wouldn't go more then 680 with 720's unless I plan on jacking the pressure though the roof.
 

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FWIW, people have been running slightly more than 1whp per cc of injector capacity on the Supra for many years (since the mid-late '90's) without issue that I'm aware of. I would feel comfortable with the 720's (some call them 750's if you're talking about the type that Precision Turbo sells) on most 67 setups. I ran those injectors on my SP74 at about 30 PSI boost (made 726 whp at that time) for a while and had no problem keeping the AFR in the 10's if I wanted. I run 45 PSI static pressure.
 

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Boost Creep
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A lot of the VPC setups will work just fine at 34 PSI or so. I've been running mine at 28-34 PSI for about 6 years now and it works fine. AFR's are just fine, etc. I did have a VPC pressure sensor crap out about 3 years ago and I bought a new one. With the new pressure sensor AFR's started getting lean as boost went above 25 PSI. I picked up a different pressure sensor from a local friend and it worked like my original -- I can run 34-35 PSI and AFR's stay just fine (in the mid-11's with all the controls on the VPC and SFC set flat (no fuel added or cut). If I run lower boost, like say 25 PSI, I have to pull some fuel with the SFC or it'll be down in the mid 10's, which is lower than I like.
I'd love to see what my car could do on 34PSI with C16.. be in the 775WHP range i'd assume. Be afraid of the engine exploding though.
 

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undercover racing team
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Discussion Starter #9
thanks guys for all the replys... i ahve 1 more question...i am thinking about doing gsc s1 cams and the tubro i am oing to buy is a .84 a/r ratio...is that going to be a problem with spool and my caris an auto with 3800stall... should i go smaller with the a/r?
 

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ok so i got a sp67 as well and a vps with the 550cc chip how and i got me 780cc injectors what do i gota do now 2 run safe with the vps and my 780s?
Are you meaning to say VPC? If so, you'll need the usual fuel system which includes (in addition to the necessary lines, wiring, rail, etc.) a 1:1 fuel pressure regulator and enough fuel pump(s) to maintain about 40-45 PSI fuel pressure greater than manifold pressure even when you're at full boost (2 stock densos are a good way to go), a fuel controller such as an AFC to tweak the A/F ratio as needed, a wideband to monitor A/F ratio, and enough octane in the tank for the power you're making. If you have those items and use them correctly (the wideband and fuel controller) you can run safely.
 

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I want to buy a 67mm turbo but I’m not sure if I have to buy injectors also I’m running 720cc injectors now with a vpc with b chip and SAFCII and I don’t want to max out the injectors I will run 30psi boost with some c16 at track and 18psi on 93octane for street... any information is greatly appreciated
do you have two fuel pumps
 
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