is 20 psi possable?

[Twisted Sid]

i work with a guy that has an '89 auto and is running 16 psi right now. he is wondering what all he needs to safely push to 20 psi. he has the following done already:
HKS fuel cut defender
nopi 3'' down pipe
2 1/2 straight pipe from d/p to magnaflow muffler no cats
manual boost controller
home made intake made from aluminum piping and cuplers
nopi blow off valve
NGK iridium plugs
after market boost gauge

what do you all suggest?

[bgrieger]

possible -> Yes

advised -> No

The CT-26 (I would assume it is) turbo ran out of steam about 4psi ago already. It will generate more pressure, with exponentially more heat, and a little extra power the more pressure you push through it. You don't mention fuel mods, and he uses an FCD...it is almost shocking that it is still in one piece, or at least that the pistons are. I would have expected a hole in one of them at this point. The factory computer has no fuel curve beyond approximately 12 psi worth of airflow. The lack of an intercooler upgrade is also going to choke things off, and certainly isn't helping the heat problem.

I suggest he figure out what he wants and go from there. If power is his thing, and he wants it to last more than a week, he has an expensive path to head down including engine management (emanage etc), turbo upgrade/replacement, a real exhaust system, intercooler, injectors & regulator & pump etc. If he couldn't give a crap about longevity and just wants to crank it till it blows, he's already on the right track!

[Jeeves]

[Pretend this is a duplicate post of what Bob said]

FCD's are BAD news.

[Twisted Sid]

Originally Posted by bgrieger

possible -> Yes

advised -> No

The CT-26 (I would assume it is) turbo ran out of steam about 4psi ago already. It will generate more pressure, with exponentially more heat, and a little extra power the more pressure you push through it. You don't mention fuel mods, and he uses an FCD...it is almost shocking that it is still in one piece, or at least that the pistons are. I would have expected a hole in one of them at this point. The factory computer has no fuel curve beyond approximately 12 psi worth of airflow. The lack of an intercooler upgrade is also going to choke things off, and certainly isn't helping the heat problem.

I suggest he figure out what he wants and go from there. If power is his thing, and he wants it to last more than a week, he has an expensive path to head down including engine management (emanage etc), turbo upgrade/replacement, a real exhaust system, intercooler, injectors & regulator & pump etc. If he couldn't give a crap about longevity and just wants to crank it till it blows, he's already on the right track!

ok i will tell him all ^this^. he has been running this setup for about a year or so which = about 1500 miles he said. its not his daily driver.

so what parts do you all recommend he up grades to. i.e. intercooler, injectors, fuel pump, management? i tired telling him last year when he did this stuff to upgrade to a better F.M.I.C. atleast but he was told it would be fine for his setup. i also told him he needed more fuel but the guy that installed these parts told him it would be ok as long as he didnt go past 16 psi. glad to see i was correct about this one.
thanks for the help so far.

[bgrieger]

He should start with fuel. Step 1, turn down the boost to 12ish PSI and ditch the FCD. There are many routes to fuel computer hacks and replacements, but for a supra, on the fairly cheap, he could look to the old, but effective lexus/550 mod. I'd recommend a fuel pump and regulator at the same time, and a quick search on bypassing the J tube. All is pretty simple with a search. Next search: on LEXUS AFM here, or at other supra sites such as supramania.com will give all the details, but the idea is the sc400 used the same afm, only the body was 25% larger. A larger meter with the same sensor will mean the computer sees 25% less air than it is actually getting (it thinks the smaller meter is in place). Conveniently, 550cc injectors are, surprise, 25% larger. A nearly perfect match. He can then fine tune with an safc or similar. The upside to all this: because the computer thinks there is less air moving through, fuel cut is delayed and you can run higher boost. Fuel is cut at an metered air volume, not boost pressure. Fool the computer to think there is less air, and you get higher real airflow numbers that are fed through more boost.

This should take a bit of time to get together, but will take him quite a ways, and he can likely run 16psi boost happily for the rest of the car's life. To go further, the turbo needs an upgrade, perhaps a 57 trim upgrade would be my compromise choice as 60 trims tend to have shorter lives for little extra gain, and 54 trims tend to be very stock feeling, though definately have more grunt than the stocker. An intercooler upgrade would do him well at this point too.

As for where to get these parts, contact one of our sponsors - raptorracing - by pm. He sells a budget FPR kit that just bolts in, and may also have the parts for the j tube bypass. Actually, he sells everything but the afm and the turbo upgrade, and for pretty good prices. He's done quite a bit to help members here on TN, and has been a stand up vendor. I vouch for him, and he is a personal friend (in case you wonder about bias, I lay it all out for you to decide).

As for what to get, I have more advice on what to avoid. Steer clear of no name regulators. Many use aeromotive ones. I'm not a fan of walboro pumps, but many use them successfully. Never ever get Venom injectors...even if someone offers to pay you to take them. I use the aeromotive, bosch pump and RC injectors, but I'm anal about reliability...

[Twisted Sid]

thanks for the help. i will print this out and see what he has to say.