I get 18psi with stock turbo. Should i add a boost controller to reduce boost to 15PS

[koreanpersuasio]

HI. I have a stock turbo and i get up to 18psi on gears 1-4. gear 5 will only get 15psi. I have read here that stock turbos should see no more than 15 psi. I have a Joe P Mbc. I havent installed it yet. Should i install it to bring the psi boost down to only 15 psi? Or is it ok that my car does this? MOst of the posts i see..ppl say their car only runs at 10-12 psi. I dont want to hurt my car.

 

[Black95GSX]

Well, being that your on a T25....

As long as you have an upgraded BOV (which If I remember, you do), and some kind of fuel-system mod (a re-wired fp will do, but preferably an upgraded pump)... you should be fine


Although, back in my "t25 days".... I was running 17psi w/o a boost controller, then switched to 17 with a boost controller (a joe p if i remember).... the car felt much stronger, and spool actually went even lower.


I miss the days of full boost by 2600rpm!!!

 

[koreanpersuasio]

Really? so i should add the boost controller? Do you think i can set the boost at 18psi? I did the fuel pump rewire. I have a air/fuel autometer gauge, and when its full throttle, it stays in the green (rich) area. I just wasnt sure if it was worth puttin on that Joe MBC.

 

[AWDSOME]

Are you sure that your boost guage is reading accurately? I am sure it is possible that you are hitting 18, but it is alos very possible your guage is wrong.

 

[koreanpersuasio]

it is an autometer boost gauge. i bought 2 and i tried them both. they both read the same psi boost. i thought it was amazing too since i read everyone elses is around 10-12

 

[Black95GSX]

Alright, first off before I even begin to address your question.

Do yourself a favor, get an EGT Gauge. do NOT rely on the autometer "blinky" gauge, it is not accurate enough to fine-tune air/fuel ratios on a turbo car. If I rememer correctly, the gauges are accurate to .08 or .09v...... which is enough of a difference to blow your motor. Furthermore, you don't know what LED means what.

Do NOT trust that gauge with your motors life... that would be like giving a gun to a monkey with a full clip and no safety




But yes, install the boost controller, and turn boost to 15psi. Once you have an EGT gauge or a REAL o2 meter (read: jumptronix)... then you can go further, but I would really suggest an EGT Gauge before pushing the car, and (more importantly) your motor's limits.

 

[koreanpersuasio]

hi, thanks alot for your info.

i am on a tite budget since now i have to replace the thrust bearing.

what models of EGT gauges are there available. I saw the jumptronix one and it didnt look that great. like one of those digital clocks..heheh...is there any other options? brands? thanks

 

[BoostinAWD]

Does the dsmlink read 02's? If it does I would recommend one of those they are a hella lot more useful than an 02 guage.

 

[L2RTSiAWD]

The DSMlink reads everything.

Later,

P.S. he said monkey

 

[98TsiAWD]

Originally posted by koreanpersuasio
hi, thanks alot for your info.

i am on a tite budget since now i have to replace the thrust bearing.

what models of EGT gauges are there available. I saw the jumptronix one and it didnt look that great. like one of those digital clocks..heheh...is there any other options? brands? thanks

The jumptronix.com is a air/fuel meter (more accurate than the guage), as far as an EGT, go to eguages.com and get an Autometer one that reads 0-1600 degrees, make sure to get one that includes the probe and wiring, they are about 125 bucks.

 

[Black95GSX]

Jumptronix may not be pretty, but it is one of the, if not the most accurate AF gauge around

 

[tjh-dsm]

Black95GSX, you are a moron and know nothing, if I see you in the street I will run you down w/ my B20 powa Civic hatch.

Hey Rob, bored at work again? Me too!

 

[Black95GSX]

Travis, don't make me take my old turbo off your car....

 

[tjh-dsm]

Rob, I can't believe you got a new manifold and didn't tell me! What crazy ass plan do you and Kevin have now? Just curious, what are you planning to do w/ your Garrett manifold? Also, where are you gonna keep it? hah j/k

 

[Kevin Jewer]

I'll asy it again... It doesnt matter how accurate the guage is, the sensor is the problem. It varies from car to car, from setup to setup, and from day to day. Enjoy.

Dont bother running the t25 at 18 psi. I have logged every psi posible on hte t25, up to 24. 16 is the highest you want to go on pump gas on a well running car.

IF you are replacing the thurst bearing because of crankwlak, good luck to you IF you are replacing it for some other reason, there is an even BETTER chance it crankwalk. Dont ask me how I know, But after CWing 3 factory 95 motors, and trying to repair one by changing the thrust bearing I now have a 120k miles 6 bolt that is living a happy life in there. Just trust me on that.

Good luck.

 

[koreanpersuasio]

hi, what is a 6bolt? i dont know that much about engines. i have heard that term before. as for the thrust bearing. the mitsu dealer said they have to take the engine apart to see what needs replacing, i.e. thrust bearing, crank, or possible block

 

[CyberDSM]

Thrust bearing, crank, possible block? Not that crankwalk mess is it?

 

[koreanpersuasio]

yep it is crankwalk. my crank endplay is at .012! it supposed to be .002 - .0071

 

[CyberDSM]

That sucks man, make sure you do some homework on the subject. A 6bolt is an engine from a 1g. They don't crankwalk (as often). A lot of times people just swap in a 6bolt so they don't have to worry about it anymore because sometimes even after the dealer tries to fix the problem, it still crankwalks.

 

[koreanpersuasio]

oh ok. yea, im kinda depressed about this whole crank walk thing. i just bought the car in may. and now this problem. i am hopin the dealership will help cover the costs...im callin them back today to see what they have to say.

 

[Kevin Jewer]

I have never heard of anyone that successfuly (key word ) repaired a crankwalked 7 bolt (93 up, 90-92 is usually 6 bolt). The dealer replaced the whole shortblock in my car, and it still crankwalked 3 separate motors. The 6 bolt seems fine so far. And the service limit is .009, but either way your motor is done. It a lot of fun when they get up to .040 play though

 

[BatmanGSX]

You can't lower the boost of the stock system with a boost controller. Duh. I can't beleive nobody else said anything.

You probably have a bent wastegate actuator bracket.

 

[Kevin Jewer]

Stock boost is 14psi. Wastegate spring is 7-8 psi. So yes, you could lower boost with a MBC. Also, if he is refering to boost spike (hard to tell with the t25, since it drops off either way) which is cause by the boost controller (not reacting fast enough) then that will also lower boost if it cures the spike...

 

[BatmanGSX]

Originally posted by 95GSXracer
Stock boost is 14psi. Wastegate spring is 7-8 psi.

You're right, I'm stoopid. I deserve to be made fun of in this case.

 

[Kevin Jewer]

I wont make fun of you, this stuff is a bit confusing. The funny thing is the more you know the easier it is to get all mixed up. I do it all the time.