ok my supra is almost stock i have a air filter and a bosch bov boost gauge and af gauge my aftermarket boost gauge says its only boosting 5psi i just got a mbc and i wanted to know what i can safely turn it up to for daily driving i was thinking maybe 10psi let me know thanks
turning boost up?
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fastsupralife said:
*sits down to catch his breath after reading this*
Stock boost is around 7psi. You can go up to about 10 safely but will probably hit fuel cut anywhere between 10-14 psi depending on your setup.
Just a word of advice. Please use grammar etiquette next time. (ie, periods, etc...):biglaugh:
fastsupralife said:
fixed!
next think on your list should be a more free flowing exhaust. the stock dp and elbow are pretty restrictive. these will also raise your boost level naturally as there will be less back pressure in the exhaust track.
My vote is to turn it up until you hit fuel cut, then back it down a wee.
You'll know when you hit fuel cut too.
You'll know when you hit fuel cut too.
are you still running the original HG? if so don't turn the boost up unless you have re torqued and even then I would be worried.
If the HG hasn't been replaced and doesn't have either ARP Bolts or Studs you will get BHG.
Keep it stock until then.
If the HG hasn't been replaced and doesn't have either ARP Bolts or Studs you will get BHG.
Keep it stock until then.
I would suggest getting a 3 inch full exhaust before touching a boost controller, its a disaster waiting to happen. Your stock boost is 6-7, i can't remember nor do i know first hand cause my stupid stock boost guage was in vacuum. Some people say 6, some say 7.....i say if it pushed 7 over 15 years ago, its 6 now :icon_razz
Dont mean to hijack the thread (kinda noob question). so if u turbo back, intake and are hitting f/c, cou8ld u turn down the boost to avoid f/c??
Depends. If you are using a boost controller to increase your boost after replacing the exhaust and intake, then sure.gp-7mgte said:
If your boost has scooted up high enough to hit FC without installing a boost controller, then you are seriously SOL.
GrimJack said:
well i guess i am SOL, would probably mean i have some kind of boost leak somewhere?
How could you increase boost if you have a boost leak? :icon_confboost PSSH boost said:
fastSupra: first thing you need to do is basic maintanence... Make sure your car is ready for higher boost... Check all your piping, tighten the couplers, look for worn out hoses, elbows, etc... Then do a compression check, wet and dry, warm and cold... Next, replace your spark plugs with either copper or iridium, never NEVER platinum... Do an oil change, filter change... Finally, if you ARE on the stockk head gasket, the least you should do is torque your head bolts down to 70-75 pounds, follow the proper torque method...
After you have done all that, invest in a 3" exhaust... Even if you cant afford a full turbo back, atleast get the down pipe back... When you do that, you will notice a WHOLE new car... It wakes up like you wouldnt believe... On my last supra, I had a cheap ebay down pipe, stock elbow, mild steal (crush bent) 3" pipe to a 3" can muffler... When I went in the muffler shop, I was doing 6psi... When I pulled out and got on it, the boost guage pegged... I freaked... When I installed my after market boost guage, it read 10psi... On cold mornings, it woul dget up to 11 or 12... Usually, at 12, it hit fuel cut... And let me tell you, if you've never experienced fuel cut, the first time it happens, you'll shit your pants... Well, maybe not shit, but it'll freak you out.. Its INCREDIBLY violent... So my advice is, ditch the manual boost controller, and just let that motor breathe better... It'll SOUND better too...
Good luck,
jake
doing little shit makes a huge difference.....when my motor was bone stock i hit fuel cut at 10 but now i got 3" dp(not from elbow down but from back of turbo down), full exaust, arp head studs, fully rebuilt head, intake, and stock everythign else and i dont hit fuel cut till 15 but im running 11 all day to be safe.....i wouldnt go past 11-12 on a fully stock setup with only arp head studs and stock HG....unless u put a MHG, arp's, and wideband with all that good shyt to tune it and not to detonate.....but then i heard u can go to 18lbs all day on a fel-pro HG if ur completley tuned to perfection to not get detonation....but im not taking chances with a reg HG to go past 15 lbs.....
Its not detonation that blows head gaskets... 
1: head gasket material... Stock hg's are pressed wax paper or somethign with copper rings holding all that compression (boost) in...
2: Toyota in their genius, and I understand the fear of over tightening an aluminum head to an iron block, only torqued the head to 52 pounds...
Detonation will destroy your pistons... rods... valves... block... and I guess, eventually, the hg.. but by then, the hg is the least of your problems, lol...
1: head gasket material... Stock hg's are pressed wax paper or somethign with copper rings holding all that compression (boost) in...
2: Toyota in their genius, and I understand the fear of over tightening an aluminum head to an iron block, only torqued the head to 52 pounds...
Detonation will destroy your pistons... rods... valves... block... and I guess, eventually, the hg.. but by then, the hg is the least of your problems, lol...
Reign_Maker said:
That is correct
Fuel cut is triggered by airflow measured at the AFM...it has nothing to do with the psi the stock boost gauge is sensing at the manifold. Classic symtoms of a boost leak is hitting fuel cut (occurs at ~12 psi w/ stock AFM housing) and showing less on the boost gauge (say 6-8 psi).
This assumes you already have the boost turned up to the 12-14 psi level.
detination has alot to do with it...i know ppl that blew a MHG due to detination...if i heard wrong im sorry its no my fault:icon_mad:
Reign_Maker said:
Reign_Maker said:
Not sure why you questioned my correction.... I was saying that the guy with no boost controller was hitting FC due to a boost leak. Nothing to do with the original poster's itch for more boost.
Well, fuel cut could also be caused by boost creep, especially with an upgraded exhaust and cooler weather. If that's the case, as Grimjack said, the person is SOL. They would have to upgrade the fuel and lower the airflow seen by the ECU to prevent fuel cut.boost PSSH boost said:Not sure why you questioned my correction.... I was saying that the guy with no boost controller was hitting FC due to a boost leak. Nothing to do with the original poster's itch for more boost.
So, your correction was not entirely accurate.
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