Replacing stock Turbo?

[AtlanticGSX]

Hello, I was hoping someone could give me some advice. Yesterday I noticed when I was driving around, a blue cloud of smoke come out of my car, but it only does it during boost, driving around without boost or even sitting in idle there is no smoke at all. I am thinking that seems like it is an oil leak in my Turbo, either seals or something else? I spoke with a guy I know that has dealt with turbos, he figured my turbo is filling the intercooler with oil on the vaccuum cycle and then when it switches to boosting its blowing that oil into my cylinders. What I want to know, is If i need to replace my stock turbo, Id preffer to replace it with one that is the same size etc so I don't end up having to tear down my motor and redo that too. Id preffer to do it as cheaply as possible, but I understood when I bought the car that it wasn't a Cheap to maintain toy! So any help/tips here would be great, id even consider a used turbo replacement maybe if it is in good shape etc.

Thanks

 

[vannaksgsx]

You don't HAVE TO be stuck. But if you're happy with the way your car drives now, then just replace it or rebuild it. You won't have a problem finding one on here, 99.999% of the people on here are looking to replace their stock turbo- the total opposite of what you're looking to do.

 

[Boost_187]

Buy a 16G and your troubles will be solved and its pretty much a factory replacement and a lot more durable than the T-2Small

 

[vannaksgsx]

Buy a 16G and your troubles will be solved and its pretty much a factory replacement and a lot more durable than the T-2Small

What do you mean by "Durable"?

If he is not planning on running anymore boost than stock, why would be want a 16g? So he can have lag??

 

[JusMX141]

Sounds to me like without planning to upgrade all my internals as well

You don't really need to upgrade internals to take advantage of a larger turbo, but you will need more fuel.

 

[AtlanticGSX]

Something else to consider is im using pump gas as its a daily driver not a race car. Im not sure what the fuel pump is, but I do figure its not a reg pump as it is pretty loud when the car is running? Anyone have trouble with their lock remote? i replaced the batteries in mine thinking it would increase the range, but nothing changed. Also, would anyone have a passenger side door handle assembly already painted kalapanga black? Someone misjudged the weight of my doors, and broke my door handle off.

 

[Ninja GSX]

That's the general idea behind guys using, say, an Evo III 16G. You must keep it at stock boost levels to avoid doing damage.

The trouble with that is that it is indeed a bigger turbo, so it's going to be noticeably laggier than your T25....and without the ability to run more boost to offset the lag, the car is going to feel slower.

There is more to increasing performance than how many psi a turbo can produce. How many cubic feet per minute it can flow is also a factor. The 16G flows way more CFM than the t25.

Since I haven't had the money to upgrade my fuel injectors and get a dsm link I am currently running my Evo3 at the stock boost levels. Though I still have the wastegate solenoid restrictor removed which is supposed to give 1-2 psi more boost. Everything else is stock except for the intake.

I haven't noticed all that much of an increase in lag. It spools around 3200rpm and I expect this would improve significantly if I were to replace the stock down pipe and exhaust which is restrictive. I also need to get my front mount installed.

What I have noticed is my car doesn't run out of steam past 5000 rpm like the t25 did. Overall I am very happy with this upgrade and the potential for upgrading in the future. The evo3 spanks the t25.

 

[Zdrummer15]

Sounds to me like without planning to upgrade all my internals as well, that im stuck with a t25 to give me that same snappy feeling I had before?

You're internals aren't a restriction until you are making much more power then you plan. Your fuel system is what is nearly maxed out stock. Even if you have a bigger fuel pump, you would still need bigger injectors and a way to compensate for them, in order to run more then 15-16 psi.

 

[vannaksgsx]

Since I haven't had the money to upgrade my fuel injectors and get a dsm link I am currently running my Evo3 at the stock boost levels. Though I still have the wastegate solenoid restrictor removed which is supposed to give 1-2 psi more boost. Everything else is stock except for the intake.

You're running STOCK boost, WITH STOCK fuel, on a 16g and seeing NO lag?? I find that hard to believe. What turbo did you use before your e316g?

 

[JusMX141]

there is more to increasing performance than how many psi a turbo can produce. How many cubic feet per minute it can flow is also a factor. The 16g flows way more cfm than the t25.

Really?

 

[69_luv]

If your wanting a good turbo, that is just over the stocker why not go for a 14b? I would think it would be a way way better option for him than going with the 16g. The 14b is stock from the 1g, and it flows better than the t-25. Makes a lot of sense to me

 

[AtlanticGSX]

That may be, but wouldn't that require more modifications to my headers etc to make the 14b Bolt up?

 

[Ninja GSX]

You're running STOCK boost, WITH STOCK fuel, on a 16g and seeing NO lag?? I find that hard to believe. What turbo did you use before your e316g?

I was concerned about it but it hasn't been bad at all. I think there are some factors that are working in my favor so it's not as bad as it could be. The first mod I made to my car was to put an Injen intake on it. The stock intake on our cars is very restrictivet. On a stock GST that intake adds about 10 hp but more importantly it improves the power band by 1000 RPM. Since I had already made a big reduction in lag with the intake, I could give up some responsiveness and still be better than stock.

1999 Mitsubishi Eclipse GS-T - Power Pages - Import Tuner magazine


I was running the stock t25 turbo. One of the shaft seals went so I had the choice of rebuild or replace. I chose to replace with an Evo 3. I chose the evo 3 because not only could it could flow more than a small or big 16G but the design also had improvements to make it more responsive than the big 16G. ie They lightened the rotating assembly so it spools much faster than the big 16G.

I also had the turbo ported which is supposed to help reduce lag and it is unclipped. When I get the fuel system finished the next step is a bigger down pipe, high flow cat and catback. Reducing back pressure will help improve response as well. In that import tuner build they improved the power band 500 RPM going to a 2.5 inch down pipe and the thermal research catback was good for another 30 hp.

It looks like the OP already has a catback so he has one of the restrictions out of the system, if he has an intake and a down pipe with high flow cat he should be better off than I am right now if he adds a evo3.

You're running STOCK boost, WITH STOCK fuel, on a 16g and seeing NO lag?? I find that hard to believe. What turbo did you use before your e316g?

I was concerned about it but it hasn't been bad at all. I think there are some factors that are working in my favor so it's not as bad as it could be. The first mod I made to my car was to put an Injen intake on it. The stock intake on our cars is very restrictivet. On a stock GST that intake adds about 10 hp but more importantly it improves the power band by 1000 RPM. Since I had already made a big reduction in lag with the intake, I could give up some responsiveness and still be better than stock.

1999 Mitsubishi Eclipse GS-T - Power Pages - Import Tuner magazine


I was running the stock t25 turbo. One of the shaft seals went so I had the choice of rebuild or replace. I chose to replace with an Evo 3. I chose the evo 3 because not only could it could flow more than a small or big 16G but the design also had improvements to make it more responsive than the big 16G. ie They lightened the rotating assembly so it spools much faster than the big 16G.

I also had the turbo ported which is supposed to help reduce lag and it is unclipped. When I get the fuel system finished the next step is a bigger down pipe, high flow cat and catback. Reducing back pressure will help improve response as well. In that import tuner build they improved the power band 500 RPM going to a 2.5 inch down pipe and the thermal research catback was good for another 30 hp.

It looks like the OP already has a catback so he has one of the restrictions out of the system, if he has an intake and a down pipe with high flow cat he should be better off than I am right now if he adds a evo3.

Really?

Oh yeah. CFM makes a big difference. The stock t25 is rated at 405cfm, a small 16G 505cfm and an Evo3 550cfm. Those extra cubic feet of air means you can burn more fuel. The way an engine works is by burning air and fuel. So the more that you can put into an engine the more performance. Does that make sense to you now?

 

[JusMX141]

Does that make sense to you now?

Wow, I feel like such an idiot. I never knew bigger turbos made more airflow!!

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I chose the evo 3 because not only could it could flow more than a small or big 16G but the design also had improvements to make it more responsive than the big 16G. ie They lightened the rotating assembly so it spools much faster than the big 16G.

Not by much. In fact, I've had customers that ran the Big 16G and Evo III 16G back-to-back and claimed they spool identically. The Evo III 16G's main benefit is the better-flowing turbine housing (better for peak flow; makes no difference at stock boost levels), and the fact that the compressor wheel has less "hub" area meaning the blades are longer and have a larger surface area for more efficiency despite the fact that the standard Big 16G has nearly an identical compressor spec.

I also had the turbo ported which is supposed to help reduce lag and it is unclipped.

Porting may help peak flow, but it's been proven to ruin efficiency and add lag on certain applications by ruining velocity.

The design of a turbine housing is nothing more than a funnel.....no matter how much you port the top of the funnel, you're not making water rush through it any faster unless you change the area of the funnel where the water exits. On a turbo, this is done by changing to a housing with a different area / radius than the stock housing.

When I get the fuel system finished the next step is a bigger down pipe, high flow cat and catback. Reducing back pressure will help improve response as well.

I ran my FWD with an open downpipe for about a week back when it still had the Big 16G running 15psi. Not only was it horribly loud, I also noticed that the car had lost off-boost torque. Notice I'm saying "off boost", when the turbo is doing nothing and the car is basically non-turbo.

I can report that the turbo did seem to come to life quicker and definitely pulled harder in the higher RPMs than it did with the stock exhaust, but the car definitely lost power and felt lazier off-boost, where 99% of your daily driving is done. It is possible to have too little exhaust restriction hurt your performance in some way.

 

[Ninja GSX]

Wow, I feel like such an idiot. I never knew bigger turbos made more airflow!!

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Glad I could help and that you have a sense of humor. That is a cool smilie by the way. As this is the newbie forum I was gearing my reply so it might be useful to a newbie. I'm sure you understand the relationship of cfm to performance but the OP and some of the other newbies maybe not.

I'm trying to produce useful posts so I can get my status upgraded and I've benefited from these forums so I'm trying to give back. Feel me?

 

[AtlanticGSX]

Well, My car has a greddy intake, im not sure about the intercooler, could be stock, and a 3" exhaust from the turbo all the way to my muffler. Its quite loud, and very depressing to see it in the yard unable to drive it around! I appreciate all the advice ive been getting. I am a fast learner, and that seems to be an advantage to me when it comes to this type of mechanic work.

 

[Orion97gs-t]

I have a black door handle i don't think its that black you are looking for, i also have a used t-25 turbo with a tubular manifold i can sell you for practically nothing, i have no use for it. If you are interested give me a pm i can send some picks/ prices if you would like as well.

 

[nightmares GS-T]

Oh yeah. CFM makes a big difference. The stock t25 is rated at 405cfm, a small 16G 505cfm and an Evo3 550cfm. Those extra cubic feet of air means you can burn more fuel. The way an engine works is by burning air and fuel. So the more that you can put into an engine the more performance. Does that make sense to you now?

Incorrect sir. As far as my readings have all shown the t25 only flows around 250-280 cfm. Am I right?

 

[Orion97gs-t]

nightmare is correct it run somewhere near 265 give or take

 

[Ninja GSX]

Wow, I feel like such an idiot. I never knew bigger turbos made more airflow!!

You must be logged in to view this image or video.

Not by much. In fact, I've had customers that ran the Big 16G and Evo III 16G back-to-back and claimed they spool identically. The Evo III 16G's main benefit is the better-flowing turbine housing (better for peak flow; makes no difference at stock boost levels), and the fact that the compressor wheel has less "hub" area meaning the blades are longer and have a larger surface area for more efficiency despite the fact that the standard Big 16G has nearly an identical compressor spec.

Porting may help peak flow, but it's been proven to ruin efficiency and add lag on certain applications by ruining velocity.

The design of a turbine housing is nothing more than a funnel.....no matter how much you port the top of the funnel, you're not making water rush through it any faster unless you change the area of the funnel where the water exits. On a turbo, this is done by changing to a housing with a different area / radius than the stock housing.

Now what exactly does the area / radius measure? I see that term used a lot, but I haven't bothered to look it up.

I ran my FWD with an open downpipe for about a week back when it still had the Big 16G running 15psi. Not only was it horribly loud, I also noticed that the car had lost off-boost torque. Notice I'm saying "off boost", when the turbo is doing nothing and the car is basically non-turbo.

I can report that the turbo did seem to come to life quicker and definitely pulled harder in the higher RPMs than it did with the stock exhaust, but the car definitely lost power and felt lazier off-boost, where 99% of your daily driving is done. It is possible to have too little exhaust restriction hurt your performance in some way.

It has been a while since I studied about exhaust system length so I could be off on one or two details. But the way I remember it is it's not so much an issue of back pressure that you need for torque, but cylinder scavenging. Scavenging is caused by an exhaust impulse creating a reduced pressure behind it that aids in drawing the spent charge out of the cylinder and drawing in the next charge.

Scavenging is also why cams are timed so there is overlap in the opening of the intake and exhaust valves. Because the tail end of the exhaust impulse will draw in the next charge.

With a short pipe, at lower rpm there is enough time for an exhaust impulse to exit the system before the next impulse starts, so it can't aid in scavenging. I had wondered if a turbo would interfere with this. Apparently not.

 

[AtlanticGSX]

Thanks to everyone for your tech tips, ive decided to go with a 14b + install kit. I just think this community for people who love our cars is awesome!

 

[JusMX141]

Now what exactly does the area / radius measure? I see that term used a lot, but I haven't bothered to look it up.

Area / Radius

It's a ratio of the turbine wheel's position versus the inlet of the housing, referring to the angle at which the airflow enters the turbine wheel in addition to the housing volume itself. Changing to a housing with a larger a/r will make the turbo laggier, but it will flow much more air on top end.

It's a delicate balance- too small of an a/r on the turbine housing will not allow a large turbo to flow at it's peak, and too large of an a/r will make a small turbo laggier than necessary.

 

[907gs-t]

I run the FP BT-28 ported & it's a direct bolt-on & it looks 100% stock just the way I like it.Unlike the 14b or the 16g but if I had a 1g I would run the Evo3 16g since it also looks stock on a 1g but thats me.

 

[Ninja GSX]

Area / Radius

It's a ratio of the turbine wheel's position versus the inlet of the housing, referring to the angle at which the airflow enters the turbine wheel in addition to the housing volume itself. Changing to a housing with a larger a/r will make the turbo laggier, but it will flow much more air on top end.

It's a delicate balance- too small of an a/r on the turbine housing will not allow a large turbo to flow at it's peak, and too large of an a/r will make a small turbo laggier than necessary.

Thanks for the information I appreciate it. I was constantly seeing that A/R number and I was wondering what it referred to.

 

[GsXdSmKingGsX]

Last post was incorrect... You just need more fuel bro! Walbro 255 and larger injectors should do the trick! Thats if you decide to upgrade the turbo that is! I replaced my stock turbo with a 14b and increased the boost!