You're not wrong about the taper aspect, but you are wrong about the efficiency aspect. The boost from the turbo tapers, because it can't keep up with the flow of air in the engine once you reach a certain rpm. It's a losing battle for the turbo once you get above 6500rpm. However, the 16G6 can efficiently flow 25psi (efficiency meaning making more power without blowing out useless heat) within a certain RPM range...let's say 3500-6000rpm? Again, this is only on race gas. The octane doesn't affect the turbo's efficiency necessarily, but it affects the engine's ability to run that much boost efficiency.

 

I run 22 psi on my car all day with mostly 94 octane. I think it is more than safe margine with our cars even at 93 octane. I really do think 23-24 psi on 94 octane isn't that bad either as longs as you you are not trying to top out the car holding boost for a long long period of time. I know alot of Cali folks boost at 21 psi on 91 octane so with 93 -94 22 psi is perfect safe setting.

 

03 = 20-21

 

Ok, 20 to 21 sounds good to me. I will get some pics up, I just got the windows tinted and it looks great. Also about to head out to the dyno, a friend with an s2000 and I are going to just do baseline runs. I have never done it, with any car. Should be fun.

 

I was refering to post #18 pointing out that I would rather worry about destroying my engine under high boost from knock than spending time worring about the turbo wearing out early from high boost theory.


"22 is the edge for the stock turbo......you can run it higher but you will wear it out that much faster. That's not an opinion, it's a fact that more than a few on this sight simply choose to ignore."

 

Something a woman would say

 

Brickwall please, the baseball bat is obviously not doing the job

 

here we go again, it;s base octane you are suing and knock count. because you boost more doesn't mean you making more power. and please use freaking SEARCH

 

I run 23psi daily. Now that doesnt mean I will hold 23psi till whatever my rev limit is set to. You can see my mods below. I run 93 Octane gasoline all the time and only get it from BP stations. The set ign timing and AFR allow me to run 23psi on my car on a daily basis with little to no knock activity. You have to understand also that you are probably running on a stock fuel pump. Good idea is to get the walbro 255 so you have a good source of fuel delivery when running high boost. So as your car sits - its recommended you run around 18-19psi. Note I said recommended - the rest is up to you . Also remember running high boost (22-23psi) on a stock exhaust system can be very dangerous. You will create extreme exahust gas temperatures thus causing pre-detonation (knock). So like everybody said do a search on boost, octane, gas. There are tooooo many variables other than just boost when it comes to "how much can it handle". Think about it

 

Yes (of course) Detonation is definitely an issue and you're right to point it out as a concern, but you could ruin the turbo before encountering serious detonation.

The original question asked was:

"So, I just got my evolution 8 on Tues (20th) and was wondering how much boost can it handle? And how much boost can the turbo produce? Not that Im going to get a controller and just crank it up, just questions and there will probably be more to follow. Thanks"

Without getting into all the related aspects of too much boost, I was offering an opinion on the question while presuming that the guy cared about the life of his turbo.

Correct me if I have misunderstood you and I'm NOT trying to put words in your mouth, but your comment sounds a little like you are saying don't worry about overworking the turbo - That's bad advice - whether or not my numbers are the highest acceptable boost level - there isn't anything theoretical about ruining a turbo from too much boost.

Both conditions are concerns to be watched if you have respect for the machinery you work on.

 

We need a "Turbo/Engine FAQ" section

 

hehe well i have 05 with tbe. and runing 25psi and drops to 18-19psi by red line. holds a good 20-22 till 6rpm. and im runing pump gas. 93. and some very cold nights i get boost cut. yes over 25psi i hit. and when i thow some 100oct. its lot smother. but i have no seen a diff but only but 30miles with race gas and was not pushing it waiting for ecu to see it and get all 93 out of the system.

 

I forsee a "Engine blew, HELP!!!" thread from you shortly.

 

hehehe woot woot. i dont think so been runing like that for more then 5k miles.

 

It's going to happen. Running 25psi on pump gas is plain stupid. Come on, mike, why are you doing that? Not only is it dangerous, but you aren't getting any extra power out of it. You do know that running extra boost doesn't just give you extra power...it actually reduces power by causing knock on pump gas. On 100oct, it's not a problem, but on 93oct, it's just dumb.