How much boost?

[deadlois]

For the hotairs in mostly stock form, how much boost should they run safely?

 

[85 t type]

12 to 15 is the norm i have my t type at 16 it runs great its all stock with the excption of a k &n filter

 

[deadlois]

what kind of fuel pressure do run with that boost?

 

[85 t type]

i dont realy know what pressure its all stock so i guess stock pressure any one know

 

[Spool'n Fool]

I'm running my 84 at 40 psi fuel pressure and 14 to 15 PSI boost. Works fine with following....

Upgraded ECM to a 87 Upgraded ignition module and coil /87 style w/ caspers wiring adapter 87 MAF sensor and added MAT sensor K&N Cone Style Filter Custom Cold air IntakeTurboTweak Chip Walbro 340 Fuel Pump#30 Injectors adjustable wastegate caspers electronics Injector Harness racetronics hot wire kit Billet adjustable Fuel Pressure Regulator 160 Degree thermostat Fuel Pressure Gauge

 

[cool 84]

what kind of fuel pressure do run with that boost?

It depends on the chip and other factors. If you're all stock and you're just turning the boost up a few psi, you should be ok with the factory regulator. This assumes the fuel pump is adequate. Stock I think they ran ~12psi and would "overboost" momentarily to 15psi.

FWIW, I could run a little more boost on my hotair before I added the intercooler. I was able to run a solid 17-18psi with no knock on pure pump gas. This was back when 92 was available in CA.

My dad's hotair ran ~20psi on pure pump gas with a little knock on the shifts. At that boost level it went 14.0@100mph only other mods were a chip, filter, and adjustable regulator. Going from memory back to '95 that car liked fuel pressure ~43psi.

We tried good gas and raising the boost past 20 but the car wouldn't go faster and actually ended up slowing down a little. I think the little hotair turbo was all out of breath at those levels.

I managed 106mph traps with my stock turbo with a modded motor and 17psi but that's all it had in it. The wastegate was wired shut and 17psi was all it would make. I ended up breaking the turbo.

So far I haven't seen anyone else running that kind of boost on pump gas.