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15 psi FASTER than at 18 or 20 psi

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SpoolingSpyder

15+ Year Contributor
115
2
May 6, 2004
Peoria, Arizona
Ok yesterday I re hooked my boost guage and turned down my psi from 18 to 15 psi. The thing is..my car feels 75% FASTER at 15 psi than it did at 18 psi? When I first installed my 14b turbo. I set the psi to 16 felt strong(50% better than the t25 at 16 psi). Then I set the psi to 18 then 20 PSI for shits and giggles. OMG was I ready to head down to the track and run a 10 second 1/4 mile..kidding, but It just felt dsmn fast. Now 6 months down the road. The 20 or 18 psi dosent even feel 50% of what it used to. Its even worse at WOT. I feel a total loss of power. Then the other day lowering the psi to 15. My car feels somewhat alive again(WAY better than 18 psi NO DOUBT). I have been usuing 87 oct for the past few days, but i had ALWAYS before that used 91 octane. What gives? Am I in need of some tuning? can i restore my 20 psi OH SHIT THATS FAST feeling? Any comments appreciated. Thinking of going a safcII and a dyno tune. Will that tell alot?
 
yea i would try to get it tuned. but i think running that much boost u will need some fuel upgrades, i would say if u installed a fuel pump like a Walbro 190 or 255 and some minor tunning u wold be ok.
 
i wouldn't recommend using 87 oct on a stock turbo eclipse, let alone a modded one.

What IS your list of mods?

And also a dyno tune will never hurt, especially since they can tell you if you are running too lean with the 87 oct....


:p
 
got_no_sol said:
i wouldn't recommend using 87 oct on a stock turbo eclipse, let alone a modded one.
What IS your list of mods?

And also a dyno tune will never hurt, especially since they can tell you if you are running too lean with the 87 oct....
:p
click his name for his mod list.

Its sounding like you may be heat soaking your stock smic.
 
Yea, 18-20 psi in this hot weather really gets the sidemount heatsoaked quickly. Check for something simple like a boost leak too.
 
DevilSperm said:
yep, buy a frontmount before you turn it up anymore...and i dont think the 14b can handle 20 psi everyday
I think the 14b can handle it.
Just not the 2g shitmount (sidemount) can handle it.


Also if your running 87 octane in that car I am going to kill you. At least 91 please!
 
I read your first post and saw a few things I think I can help you understand. SIX months ago even in AZ the temp must have been cooler, maybe 20-30 degrees cooler. Now that it's summer time and temps are reaching 90 and higher, High boost and low octane will not mix well.. 98RedGs called it right your heatsoaking you stock sidemount and the knock you were getting at 18 to 20psi was pulling timing and costing you power. Lowering your boost to 15psi allows your 14b to move air into you sidemount without overheating it to much. Keep the boost down till you start running 91 to 93 octane again and also think about getting a FMIC.
 
Another vote for boost leaks!

I'm betting you're leaking metered air to atmosphere, which is causing a richer A/F ratio at higher boost than at lower boost.

Other than that, what's up with trying to use 87 octane pisswater at 20PSI?
 
Ok the 87 has to go. I was using temporarily because of the HIGH rise in gas price and my 70 mile 1 way trip to work. Its 91 oct again from here on out and APPRECIATE all the responses. I must say my car is running alot healtyer at 15 psi. I can actually feel the power. But untill I get a safcII and the FMIC and 18g sitting in my garage installed. Its 15 psi...thanks my friends.. Pics will follow as I get the installs. Oh did I mention I won Import Vs Domestics 1st place street class car show..? hehe
 
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