9 psi on stock compression . . .

[TRD_solaRa]

Sup all,
Alright, so there is a guy in Hawaii with a white 5speed V6 Solara just like mine, except he has a SC with a 9 lb refridgerator pulley! :shock: But, the thing is that he still has the stock 10.5:1 compression on his car. So far he has full exhaust, fuel system + other mods. He has had this on his car for quite sometime now . . . over a year at least. My question is . . . I thought that the engine can't handle over 7-above psi without modding the internals of the engine? I've done quite a bit of research now and this kinda stumbles me. And he doesn't "baby" his car either . . . as he fricken lights up his tires everywhere :!: . Any input?

d

(* Yea this is the same post I made on the camryman.org forum)

[TadS]

Hold-up is a subjective thing. How long will it hold up is probably a better question .

[Hsakuragi]

the fuel system helped a lot on this case

[Yanks0114]

I believe it was TRD that had a car running 13psi until they blew the engine.

hsakuragi is right, the fuel system helps.

I would never run that high off boost without an intercooler and/or low compression heads or forged internals.

[xtychx]

Hmmm...I think it should be relatively OK. The fuel system + the fact that he can get 93 in hawaii means its should be fine.

-xtychx

[Yanks0114]

Hmmm...I think it should be relatively OK. The fuel system + the fact that he can get 93 in hawaii means its should be fine.

-xtychx

Thats still a lot of boost for such high compression. at around 5.5PSI, your engine will have about 1 bar (14.7psi) of pressure.

Whats the altitude in hawaii. The only way you could safely get away with it if it were very high above sealevel

[bkp_duke]

Depends on which island. Parts are at sea level, parts of the Big Island go up to 8K feet. Most likely he is on Oahu though (the most populated island) and it doesn't go very high at all (1K).

[808Camry]

Most of Hawaii is pretty much AT sea level. 9PSI is hard for me to swallow. I'm seeing probs running stock boost as it is here with the 92 Octane. We don't have 93, unless there's a secret pump somewhere. But we do have 100 octane race gas from 76. I would love to see his setup, sounds crazy if that's the case.

[shidosha01]

9 psi on stock internals?!? I HIGHLY DOUBT THAT.

[Paladin06Greg]

I know this is off subject but, where did you get you hood prop rod??

9 psi on stock internals?!? I HIGHLY DOUBT THAT.

[boneezy]

the fuel system helped a lot on this case

yeah that the only way that could happen, 9 lbs is doable.. but like tadS sed.. how long will it hold up

i doubt itll hold up for 5K more miles

[Mole]

geeze.

that engine is going to go KA-BOOM!

im suprised my car is still holding well.

[Jaimster]

9 PSI!!!! Dude, you're are driving a ticking Time Bomb! Be careful man, the 1MZ is not made for that much pressure!

[JoeB]

First I'm curious what is the diameter of the pulley? I wonder if he is going by measured boost or the diameter of the pulley. The info that I have says a 9psi pulley is 2.2" diameter. However, I think that boosts to 11-11.5psi (Rizal?).

I believe he can do this with 9psi of actual boost. If he's done fuel system upgrades to support it. In cold weather, my 2.6" 7psi pulley will read as high as 10.5psi. On warm days, it reads 8.5psi. I've been running this pulley hard for a while now.

When I first got the supercharger and decided 4psi wasn't enough, I asked many places about safe levels of boost and got the familiar answer that 5.5psi was all I could do safely with pump gas. Having 94 octane available locally, I went straight to the 2.8"pulley that should be 6psi but read 7-7.5psi. I realized I needed some fuel system upgrades so went with the URD fuel system upgrade including Walbro 190lph pump, Bosch 318cc injectors and SS FTC piggy-back computer to control air/fuel and timing. Then I decided it was running so well, I could go to the 2.6" 7psi pulley that actually gave me 8.5psi. Then realized I needed to do more fuel system upgrades so I modified the fuel regulator to 59psi and added the fuel line and filter upgrade from Jim@ForeignAffairs.

This past weekend, it was running so good I decided I'd put a 2.4" 8psi pulley that gives 10.5psi mesured boost on, fully intending to take it right back off. I just wantedd to check it out. I've listened to everybody tell me that it is too much boost and I'll blow my engine. However, the EGTs still looked good (did not go up at all), air/fuel still looked good, there was a little knock but nothing the ECU couldn't pull out (not even audible) and the hp gain (measured on G-Tech Pro Comp) was very linear accross the entire rpm range. Running 94 octane gas at close to sea level, I still don't know the limit... I'm still not sure I'll leave the 2.4" pulley on there, definitely not in the winter and that's as high as I will go (I think ). Still confused... -JoeB

***EDIT || UPDATE***
I was referred back to this thread by a member and asked a question about it. I had completely forgot about it and now feel the need to update it. At that point, I was looking for the limit the motor could handle. Eventually, I blew the motor, all 6 piston ring lands were damaged. By looking at the damage, I would say it started when I went to 7psi and got even worse at 8psi. For those reading and wondering a safe limit for stock internals, I would not got above 6psi. That is with good fuel upgrades, 93 octane gas at sea level, an A/F pigy-back and good tune. For people stuck with 91 octane, I'd stick with 5.5psi unless at high altitude.

[cdssolara]

Joe,

I see that you're still experimenting! You haven't done anything to lower compression or beef up the internals, as I recall, so it's amazing that your car is doing so well. Do you think that your water injection kit is helping with that? What kind of hp numbers did you get with the 2.4" pulley, by the way?