the 5sFE Turbo Upgrade Info

[tankd0g]

Can't you use a wideband o2 instead of a 2 bar map?

[Luckynumber5]

^ no, the MAP sensor reads pressure, the wideband 02 reads gas levels in the engines exhaust.

You could do this if you had a standalone and a perfectly tuned VE table for that engine, but you are relying on nothing but 02 readings and the throttle position sensor to figure out the fueling, something as simple as a barometric pressure or an altitude change could cause the engine to run too lean or too rich.

A lot of 80s EFI engines did not use any pressure or air volume metering system at all, just a good VE vs TPS table and an 02 sensor. But no forced induction EFI engine I know of came from the factory without a pressure/vacuum sensor or an air metering device.

[tankd0g]

Originally Posted by Luckynumber5

^ no, the MAP sensor reads pressure, the wideband 02 reads gas levels in the engines exhaust.

You could do this if you had a standalone and a perfectly tuned VE table for that engine, but you are relying on nothing but 02 readings and the throttle position sensor to figure out the fueling, something as simple as a barometric pressure or an altitude change could cause the engine to run too lean or too rich.

A lot of 80s EFI engines did not use any pressure or air volume metering system at all, just a good VE vs TPS table and an 02 sensor. But no forced induction EFI engine I know of came from the factory without a pressure/vacuum sensor or an air metering device.

I though this was all honda guys did with theirs, tune the maps with something like turbo edit and a wide band, give the wide band back to the guy you mooched it off of and just run the settings. any idea what Hondas use for a MAP/MAF? I'm fairly certain I've never heard anyone talking about having to by a $300 sensor as part of their turbo build on a Civic, could it be that v-takkk motors already come with one?

[Luckynumber5]

Yeah, use a wideband to tune the fueling tables, then get rid of it. You asked about using a wideband instead of a 2 bar map sensor, they are both important but have two different functions.

You don't have to buy a 2 bar sensor, a lot of people run a setup where they have a check valve on the stock map sensor and it makes it so the stock map sensor never sees pressure (1 bar sensors only read UP TO atmospheric pressure and tend to freak out when they see positive pressure.)

This setup works, but using a map sensor that reads pressure is a better way to go if you want to make a lot of power.

edit: $300 for a sensor is unnecessary, buy a used Supra map sensor or a MR2 sensor for like $20 off ebay

[runabout93]

I've read this on the Mr2 boards over and over again.. Anyone successfully run a turbo'd 5sfe (5sfte setup... not the 5sgte) for an extended period of time? I havent heard of one person. I was going this route a year ago and started hearing of blown this, rebuilds, and people selling all of their turbo parts after giving up. Maybe the majority goes to aggressive or cheap... a lot of variables here. But, I'ld like to hear the guy who did it and keeps running it.

Anyone?

[Luckynumber5]

Pressure2 over on celicatech has a 5sfte running 240+ wheel horsepower and no problems.

[runabout93]

Originally Posted by Luckynumber5

Pressure2 over on celicatech has a 5sfte running 240+ wheel horsepower and no problems.

Didn't find the user with search. Can you post a link to that info?

[Luckynumber5]

numbers were a little off, his sig says 235 whp and 273 wtq

http://www.celicatech.com/forums/member.php?userid=55

[runabout93]

oh... it's presure2 with one "s" That's a cool ass ride. He's like some kind of god on that forum. So, is he the only one? Did he get a freak of nature.... Like someone at the factory decided to beef-up this particular motor? Why is this such a problem for other people?

Any other examples?

[Luckynumber5]

none that I know of, generally Toyota engines are well built off the assembly line, any engine will blow if its running too much timing or too lean, with the right combination a factory engine can support a good deal of power.

He is obviously running a good tune, the right spark advance, a good turbo makes a big difference (the stock ct-26 is crap in my opinion) and water/meth injection.

[Rdizzle]

90% percent of the time an engine will blow on boost due to lean conditions or poor timing. Make sure both those are acceptable and your engine will run just fine on boost.

edit: oh yeah, major thread revival....