Boost question.

[AznDrftr.]

Runnin stock boost, was good, very smooth. Well, i wanted to up the boost, so i did, to 12, which is still safe right?

Well anyway, question at hand, when i reach boost, like almost full boost, my damn turbo sounds like its a damn jet plane, like a supra type whine, is that okay? Or...did i do something wrong?

Please let me know, i know the turbo isnt going out, its a relatively solid turbo, just when i upped teh boost, it does this, to 12, and im runnin pretty much stock sr, so yea.

[smelly240]

maybe u have a boost leak or somethin? can u take a vid of the sound?

[AznDrftr.]

its not even a boost leak, cuz im reachin full boost. easy. :)

[BoostinGST]

its not even a boost leak, cuz im reachin full boost. easy. :)
it could still be a small boost leak, run a boost leak test on it before you scratch that out...

[AznDrftr.]

Hmm, i'll give it a go, and make sure everything is secure.

[unicoladron]

I'm having the same thing on 7psi directly connected nipple to the wg. when i had the turbo out, it had a small amount of play and spun freely. i feel like the turbine is rubbing on my compressor housing. i think i know what you're saying, it's not spooling up with that nice whistle, it's like a harsh noise and it's not like a squeak or squeal or grinding. it's kinda hard to explain.

[50/50]

I'm having the same thing on 7psi directly connected nipple to the wg. when i had the turbo out, it had a small amount of play and spun freely. i feel like the turbine is rubbing on my compressor housing. i think i know what you're saying, it's not spooling up with that nice whistle, it's like a harsh noise and it's not like a squeak or squeal or grinding. it's kinda hard to explain.

Sounds like too different probs. I dont think your "..turbine is rubbing on the compressor housing...", I think you mean the compressor wheel is rubbing on the compressor housing. Your problem could be the shaft play you mentioned and the compressor wheel is touching the housing. His sounds more like a leak, maybe at the internal wastegate at the back. Plus at 12psi on a small turbo the shaft speed is going to be very fast, probably near 100,000 rpm, so he might be hearing a "whine" from that. If your compressor wheel is touching, you'll feel a jerky kinda buildup of boost or the boost would not "easily" get up to where your boost controller is set at.

[slider2828]

Yah what he said, also if you have a open mushroom and no airbox like the HKS intakes or Greddy, you are going to hear it because that is like an echo chamber for your turbo. Dun worry about it. When I blew my T25, there was no difference in sound or anything at all.

[GabeS14]

another question to ask is, have you had turbo cars before this one?
are you familiar with the sucktion sound higher boost makes?
when you up the boost and its the first time, it could seem like its gonna blow or somethign because or the ammount of pressure being doubled, (double the sound)!
i remember first time i turned boost up to 16 psi, after bigger injectors, my BOV sounded like a damn lazer farting, (teww teww teww tewww)before that on 7 psi, it only made a quick tweet like a quick whistle..

[SOCAL240]

^^^ same thing here im on 7psi stock and i only hear a tweet like a whistle
what im reading sounds scary though i hear that 12psi is safe and this and that
i personally would only go up to 10psi to be on the safe side

[kevtrinh]

Check your gaskets ie. Manifold/Turbo.

[AznDrftr.]

Yea its only like a whine, nothing grinding or nothing, just sounds like its spooling faster since i uppped the boost. But i think thats all that is.

Its whinin due to faster boost/psi, so i think im good, cuz i checked everything.

Also, just a note, im at 11psi, not 12.

[drift_student]

run 14psi and go to the track!

[downshift_sideways]

run 14psi and go to the track!
Dude what a fucking stupid post.:hammer:

First. What type of turbo do you have?

[White Comet]

yeah, ur def hearing the turbo spool, not a bad thing at all

[downshift_sideways]

I think 12 psi is safe on a t25 if you have a 255 fuel pump.

12 psi on a t28 is fine.

[fliprayzin240sx]

Well my better question is with more air, what are you doing for more fuel? Safc, fpr? anything at all? Also, hope you got a fmic, stock sidemount sucks after 10 psi.

[AznDrftr.]

dang mike, i didnt know you were on here lol. Haha, i will go to the track soon. yea thanks guys, i think its the turbo i hear spooling now, its a lot clearer now since the boost is up.

Also, i do i have an upgraded fuel pump so runnin 11 pso, shouldnt be bad. I have fmic, so im good lol.

thanks.

[fliprayzin240sx]

dang Dustin, i didnt know you were on here lol. Haha, i will go to the track soon. yea thanks guys, i think its the turbo i hear spooling now, its a lot clearer now since the boost is up.

Also, i do i have an upgraded fuel pump so runnin 11 pso, shouldnt be bad. I have fmic, so im good lol.

thanks.

Im not talking about the pump, im talking about extra air with more boost, you need more fuel to compensate for it and keep the car from detonating. Basically, change the fuel map or just squeeze more fuel in there. Piggyback or an adjustable fpr if you really wanna be cheap.

Easiest way to kill the engine is bumping the boost without adding more fuel...thats how you melt pistons and get rod knocks...tuning is key...

[AznDrftr.]

Im not talking about the pump, im talking about extra air with more boost, you need more fuel to compensate for it and keep the car from detonating. Basically, change the fuel map or just squeeze more fuel in there. Piggyback or an adjustable fpr if you really wanna be cheap.

Easiest way to kill the engine is bumping the boost without adding more fuel...thats how you melt pistons and get rod knocks...tuning is key...


ahh, what is a fpr? yea i want to have a sr for a while, so please let me know.

[slider2828]

FPR probably an aeromative with a B and M meter on it. Turn it up to 55PSI with the vacuum off... Should be good. Do a search a lot of posts on this

[RedtopTech]

FLIPRAYZIN240sx, you must have been a honda guy or something else with speed density fuel control because since the his 240 uses a mass air type fuel system the computer self compensates for more or less air which is determined by the MAFS. Speed density programs simply calculate fuel control via the TPS, MAP and IAT sensors which are used to determine load, and the crank sensor for RPM. To a certain degree his computer will compensate for the extra air just fine. Its once one of those sensors goes bad or is out of range that problems occur such as a MAFS that becomes "maxed out."

[Captain_Ron80]

FPR = Fuel Pressure Regulator.

[fliprayzin240sx]

FLIPRAYZIN240sx, you must have been a honda guy or something else with speed density fuel control because since the his 240 uses a mass air type fuel system the computer self compensates for more or less air which is determined by the MAFS. Speed density programs simply calculate fuel control via the TPS, MAP and IAT sensors which are used to determine load, and the crank sensor for RPM. To a certain degree his computer will compensate for the extra air just fine. Its once one of those sensors goes bad or is out of range that problems occur such as a MAFS that becomes "maxed out."

So lemme get this right...he can crank his boost up and wont have to worry about him blowing his engine just cuz it has a MAF??? Define a "certain degree" that his ecu will compensate for the extra air. I mean when would you know that the ECU couldnt keep up with the extra air on a stock SR? 10psi? 12 psi? 14 psi? I dont know about you but id rather have that safety net. Id rather have extra fuel in there than to depend on something that in THEORY is safe. Ive seen enough SRs pushing 12-14psi lean out that Im trying to save somebody from rebuilding an engine.

[50/50]

FLIPRAYZIN240sx, you must have been a honda guy or something else with speed density fuel control because since the his 240 uses a mass air type fuel system the computer self compensates for more or less air which is determined by the MAFS. Speed density programs simply calculate fuel control via the TPS, MAP and IAT sensors which are used to determine load, and the crank sensor for RPM. To a certain degree his computer will compensate for the extra air just fine. Its once one of those sensors goes bad or is out of range that problems occur such as a MAFS that becomes "maxed out."

Be careful with your thinking sir.

Each +1 increase in boost is worth about 7-8hp

from stock boost 7 to 11 psi = about a 28-32hp gain

now he's at 230+hp, all sensors work, still within MAFS range but oopps....injectors are maxed out on their duty cycles. Guess what, he's going to lean out a bit on the top end and do some damage maybe not much. What FLIPRAYZIN240sx is saying adds a nice saftey net cause now with a higher fuel pressure, the injectors would squirt more fuel. SAFC will not save you as much except to have the injectors start maxing out earlier in the power band but will screw with the timing maps.

[!Zar!]

FLIPRAYZIN240sx, you must have been a honda guy or something else with speed density fuel control because since the his 240 uses a mass air type fuel system the computer self compensates for more or less air which is determined by the MAFS. Speed density programs simply calculate fuel control via the TPS, MAP and IAT sensors which are used to determine load, and the crank sensor for RPM. To a certain degree his computer will compensate for the extra air just fine. Its once one of those sensors goes bad or is out of range that problems occur such as a MAFS that becomes "maxed out."

Wow. Way to spread aids. Learn what you're talking about before you try to bash someone on a subject they obviously know what they are talking about.

Because with your logic, I could just slap on a t04z and boost at 24 psi with stock motor.

Sweet.

[RedtopTech]

the factory fuel system will more than support the stock turbo guys. Thats why i said "to a point." The facotory fuel system will support around 270-280 worth of air @85 percent injector duty cycle and a little more than that for the MAFS. I understand that i should have been more specific. What i was trying to say is that the injection system will componsate for relatively small changes in air flow.

[usdm180sx]

FLIPRAYZIN240sx, you must have been a honda guy or something else with speed density fuel control because since the his 240 uses a mass air type fuel system the computer self compensates for more or less air which is determined by the MAFS. Speed density programs simply calculate fuel control via the TPS, MAP and IAT sensors which are used to determine load, and the crank sensor for RPM. To a certain degree his computer will compensate for the extra air just fine. Its once one of those sensors goes bad or is out of range that problems occur such as a MAFS that becomes "maxed out."

Since you know so much about hondas what does that say about you?

I have an s13 blacktop with an upgraded fuel pump, turbo elbow, fmic and an hks adjustable wg actuator. The wg is set at 10lbs and the elbow added 1lb of boost so I'm currently at 11lbs and it runs fine.

BTW there's nothing wrong with having previously owned a honda. It's nawt tha ryde, it's duh ryder :keke:

[Jbma327]

Your car is fine. Its just the turbo spooling much quicker like most pplz said. Up the injectors to be on the safe side.

[fliprayzin240sx]

the factory fuel system will more than support the stock turbo guys. Thats why i said "to a point." The facotory fuel system will support around 270-280 worth of air @85 percent injector duty cycle and a little more than that for the MAFS. I understand that i should have been more specific. What i was trying to say is that the injection system will componsate for relatively small changes in air flow.

wow...270-280 hp worth of air will be @85% duty cycle on 370cc injectors? Shiet try more like 99% buddy. :tweak:

[RedtopTech]

[QUOTE]Since you know so much about hondas what does that say about you?

I wasn't saying that owning a honda is a bad thing. I was simply stating the difference between the two different fuel control systems. I am a certified master technician so what it "says about me" is that i have a deep understanding of different systems, not just 240's.
I use my multimeter to record duty cycle on my injectors when i make changes to my setup. On the t25 at 15 psi the injectors have hit a peak of 73% duty cycle. with the s15 turbo at 15 psi i have recorded 87% duty cylce. After 87-90% AFR started droping quickly from 11.8 to as lean as 13.3. My stated #'s are tested and deduced concidering i wasnt on a dynop and can only estimate the actual power numbers.

[drift_student]

Dude what a fucking stupid post.:hammer:

First. What type of turbo do you have?

Why don't you go outside and play hide and go fuck yourself, :mrmeph:.

I wouldn't tell Antonio, whom I've known for a few years now, to do something I haven't done successfully.

I ran 14psi on my t25 for a straight year, beating the hell out of it as much as I can. No major problems yet. Just try to get your money's worth out of the T25.

[garbury]

Yeah i had my t25 boosting 15 psi for over a year and that sucker started shrieking once in a while when I'd spool it up. When i replaced it for the 2871, I could see some scrape marks on the compressor wheel/housing and it had significantly more shaft play than in the previous year. Power and boost was still fine, or it had progressively gotten worse and i forgot how much better it had been, but no noticeable decline. I always had the stock rubber hose and it never really made too much noise but it might have made a little more when i went from 7-15.

As for the fuel system, I had a wideband on it and on a hot summer day 100+ my afr was still between 10.5-11.5 at 15-16 psi. Dunno duty cycle but you should be cool.

Now the turbo is literally heard almost more than the bov. i have a hard intake and that sucker spools to 19 and its very loud, close to my unresonated exhaust.

[facesmelt]

I hear people saying that they are running 14 or 15 psi, well I would like to know what size Fuel Injectors you guys have, since I am in need of a new one and even with my Walbro 255lph FPR and S14 t28 Turbo I was scared of going over 11 psi, with the stock 370cc injectors on my SR20DET Redtop.

Thanks ahead of time.

[GabeS14]

I hear people saying that they are running 14 or 15 psi, well I would like to know what size Fuel Injectors you guys have, since I am in need of a new one and even with my Walbro 255lph FPR and S14 t28 Turbo I was scared of going over 11 psi, with the stock 370cc injectors on my SR20DET Redtop.

Thanks ahead of time.

I am sure you can go higher than 11 psi on stock 370 injectors
but if you want to upgrade get the S15 injectors(440cc),might be ok without tunning!maybe a little rich.
or just buy 500cc injectors, you will need AFC, or tunning though!