Why does my GSX keep getting slower with each upgrade?

[volkerding95GSX]

Hey guys! I usually try and figure this stuff out by myself, but I have no idea what to do next and I am in way over my head. Any help would be GREATLY appriciated. So thanks in advance.

I am stuck in a rut with my DSM build and was hoping you could give me some advice and/or motivation to finish it. It's been disheartening because it seems like every "upgrade" I do to it makes it slower and run worse than before. This car is the first I've ever modified and I have next to no mechanical experience besides the few bolt-ons I've put on.

The eclipse felt the fastest when I first bought it. It pulled hard and never missed out. The only mods it had when I bought it was a small 16g, 1g BOV, K&N fpik air filter, HKS cat-back, Apexi electronic boot controller and a bigger fuel pump (unknown size). At this time everything was great and I had no CEL.

Fast forward after all the bolt ons I've added: (4" Forced Performance intake recirculated, Punishment racing SMIC hard pipes, Stainless steel tubular exhaust manifold, stainless steel 02 housing dumped to the atmosphere, Megan 3" downpipe and 3" Megan cat back with cat-delete.) Now it idles just a little rough, I have a CEL, and the car feel WAY slower than it used to. It doesn't pull hard under boost. The boost gauge reads 10 psi, however I feel nothing but a slow car.

I've done a boost leak test and there was a huge leak in the coupler right after the turbo amoung a few others, so I fixed all the leaks, but it only helped minimally. Still the same symptoms. The oil, spark plugs, and wires are brand new.

Where did I go wrong? Why is my car slower after I upgraded the bolt on parts? Is it a matter of installing too many breathing upgrades and no fuel upgrades? Or should my car still run strong with the upgrades I have?

I still have plans to buy bigger injectors, a wideband, and ECMLink, but that wont be for a long while, so I was wondering if there's anything I can do with my current set-up to make it run strong again. If not, I would love if you guys could give me a rule out check list or a list of parts I would need to get my car running right again. Let me know if you need any follow-up questions from me and I will do my best to answer. Thank you!

 

[jcart953]

Yep, Link will def be the next purchase. Worth every penny, but it is NOT cheap! Shoulda never touched my car! haha, I can't leave it alone though.

Well if your really on a budget right now and will not be getting link right away you could always get evoscan and the logging cable for no more then $45 (25 for software, 10-15 for cable). This way you can : A) diagnose the check engine light B) data-log to see whats the problem.

 

[clipto]

Well those hks pump are pricey, and they run in gph so if its like 71 gph thats like 134 liters?Correct me if I am wrong but yea I don't know to much about those fuel pumps.

 

[volkerding95GSX]

Well if your really on a budget right now and will not be getting link right away you could always get evoscan and the logging cable for no more then $45 (25 for software, 10-15 for cable). This way you can : A) diagnose the check engine light B) data-log to see whats the problem.

I thought evoscan was only for 98-99? Or am I totally wrong on that?

Well those hks pump are pricey, and they run in gph so if its like 71 gph thats like 134 liters?Correct me if I am wrong but yea I don't know to much about those fuel pumps.

You and me both! haha

Would you recommend getting a new Walbro?

 

[Colt4G63 also]

You should really move "Read ECU trouble code" to the top of your list. Then link, then injectors.

If you pull your ECU out to socket it, you'll erase the code, and not know where to look for the problem.

 

[jcart953]

I thought evoscan was only for 98-99? Or am I totally wrong on that?

Your thinking about ECU Flash which is a free tuning software (provided a small donation).

Heres the link to evoscan:
EvoScan OBDII Mitsubishi Subaru DataLogger Scantool

Heres what your probably thinking of:
http://www.dsmtuners.com/forums/tuning-engine-management/347070-ceddymod-v1-ecuflash.html

 

[volkerding95GSX]

You should really move "Read ECU trouble code" to the top of your list. Then link, then injectors.

If you pull your ECU out to socket it, you'll erase the code, and not know where to look for the problem.

Oh ya, good thinking, I didn't know it would erase the CEL. I will need a wideband when I purchase Link as well, right?

 

[Colt4G63 also]

It would make WOT tuning a lot easier, but you don't need one for tuning cruise trims.

 

[clipto]

Maintenance first check the cel, dsmlink would be best it can read cel codes too, but also the best tuning software for dsm's imo.Well just look into it and all the great wonders you can do with it.You just need to make sure your fuel pump is pushing a good number of fuel, there a many different sizes for those pumps.Grab some injectors and wideband and boost controller w/ boost gauge that should make you feel the power with your bolt ons that your not feeling.

 

[doayamaha]

In my guess from what you have given is the car is boost creeping and leaning out most likely giving you knock and backing off timming. With a good free flowing exhuast the 16g loves to boost creep, do some porting to the exhuast turbine housing which should help now and later down the road, which should help to get you by untill you can get a way to tune and monitor a\f ratio this is a must as you go on in your build.

 

[jason_gsx]

Well if your really on a budget right now and will not be getting link right away you could always get evoscan and the logging cable for no more then $45 (25 for software, 10-15 for cable). This way you can : A) diagnose the check engine light B) data-log to see whats the problem.

Which logging cable is that? I have a CEL on my 99 that I need to read and the cheapest way I've seen would need the $170 Tactrix cable plus the $25 EvoScan software.

 

[jcart953]

Which logging cable is that?

This:
USB OBD-II-2 KKL 409.1 OBD2 Cable VAG-COM for VW/AUDI | eBay

Its cheap and easy to find on ebay, its what I use and works fine.

 

[Gysgt Guy]

Wow that's cheap!

 

[Calan]

In my guess from what you have given is the car is boost creeping and leaning out most likely giving you knock and backing off timming. With a good free flowing exhuast the 16g loves to boost creep, do some porting to the exhuast turbine housing which should help now and later down the road, which should help to get you by untill you can get a way to tune and monitor a\f ratio this is a must as you go on in your build.

Except the OP said this in post #10:

It seems to build boost at the same RPMs like it used to and it will stop building boost where it is supposed to as well, there is no boost creep.

 

[jason_gsx]

This:
USB OBD-II-2 KKL 409.1 OBD2 Cable VAG-COM for VW/AUDI | eBay

Its cheap and easy to find on ebay, its what I use and works fine.

The auction says it's specific to VW/Audi, that is just the software included right? The cable should still work with EvoScan.

 

[9!'clipseDOHC]

Go to any auto parts store and they will read your CEL for free. Before you spend any money or do anything else.

My first thought was also timing. Check your base timing with a light. A logger would be great to see about knock, but if you are already planning on getting v3 then just save that money to put towards link.

What octane gas are you using? When was the last time the fuel filter was changed?

Do you have an aftermarket boost gauge to confirm that you are only running 10 lbs of boost? I hope you aren't going by the stock gauge.

If you are truly only running 10 lbs of boost, then I don't think you are running too lean. The stock ECU runs super rich from the factory, so leaning it out a little by increasing airflow, should make it run better. To me it sounds like something else.

Also you said you fixed your boost leaks but I would recommend double checking it again. How mush PSI is it holding?

Hope this helps!

 

[jcart953]

The auction says it's specific to VW/Audi, that is just the software included right? The cable should still work with EvoScan.

Yea ignore what the auction says, dont use the that cd either. Use the drivers that come with the EVoscan software. If you get stuck somewhere and the software complains about bad drivers or something just re-downloaded it off EvoScan (presuming you actually buy it) because you get like 100 free downloads or something after purchase. This proved to be the fastest working remedy to fix my issue. Its been logging fine ever since.

 

[Colt4G63 also]

Go to any auto parts store and they will read your CEL for free. Before you spend any money or do anything else.

My first thought was also timing. Check your base timing with a light. A logger would be great to see about knock, but if you are already planning on getting v3 then just save that money to put towards link.

What octane gas are you using? When was the last time the fuel filter was changed?

Do you have an aftermarket boost gauge to confirm that you are only running 10 lbs of boost? I hope you aren't going by the stock gauge.

If you are truly only running 10 lbs of boost, then I don't think you are running too lean. The stock ECU runs super rich from the factory, so leaning it out a little by increasing airflow, should make it run better. To me it sounds like something else.

Also you said you fixed your boost leaks but I would recommend double checking it again. How mush PSI is it holding?

Hope this helps!

I'm too lazy to type all that, but this: ^^^^^ exactly right, and in that order.

 

[Calan]

Go to any auto parts store and they will read your CEL for free. Before you spend any money or do anything else.

My first thought was also timing. Check your base timing with a light. A logger would be great to see about knock, but if you are already planning on getting v3 then just save that money to put towards link.

What octane gas are you using? When was the last time the fuel filter was changed?

Do you have an aftermarket boost gauge to confirm that you are only running 10 lbs of boost? I hope you aren't going by the stock gauge.

If you are truly only running 10 lbs of boost, then I don't think you are running too lean. The stock ECU runs super rich from the factory, so leaning it out a little by increasing airflow, should make it run better. To me it sounds like something else.

Also you said you fixed your boost leaks but I would recommend double checking it again. How mush PSI is it holding?

Hope this helps!

Exactly.

 

[Calan]

The reason you are getting slower is because all that stuff is allowing that turbo to breathe deep and you are running way too lean. If you don't have anything to increase your fuel ratio, you are seriously headed towards a burnt up motor....I am willing to bet your computer is absolutely maxed out on its fuel trim correction and can't compensate anymore for how much air you are moving. If there wasn't anything to adjust the fuel ratio before, it was already on the very edge of what the ECU can handle on the stock settings, if not slightly past it. You MUST get the fuel to match ASAP or you WILL be paying for a rebuild at best or a new motor if it blows up...It won't take a heck of a lot when it is that far out of whack to burn up a piston, blow out the head gasket, etc... It's already right on the very edge of any of those things happening.

Please humor me here and explain your reasoning for coming to this conclusion. (It's been a long day...maybe I'm a bit slow right now).

The OP is pulling in 10psi worth of air on a s16g which is being metered by a stock MAF which is well within it's range, and a stock ECU is calculating fuel from that airflow, and delivering it through stock injectors (And we'll assume a stock working FPR at factory base pressure since it hasn't been mentioned). So please explain to me again where all this extra airflow is sneaking past the factory MAF without showing up on a BLT, and causing the car to run lean enough to light up an exhaust manifold at 2k rpms (see below), but also running lean during boost instead of rich.

It ran fine when you got it because it was choked up just enough for the ecu to compensate... Now it isn't choked up at all and you are moving too much air and not enough fuel. I promise you that if you are running that set up with stock injectors and no way to increase the A/F ratio, you are rediculously lean. That is why it runs like crap, I am absolutely sure of that. If you are on stock injectors with what you listed, you're lean. Really lean, to the point of burning stuff lean. ...It isn't anything else, you are too lean plain and simple. Don't fart around with anything else until you can get more fuel into the motor or you will burn it and be rebuilding very soon.

You may want to back off a bit on the being so sure of what is causing problems, especially with a DSM. I've seen plenty of cases (myself included, more times than I can count) where "it HAS to be that" and it turns out to be something way out in left field.

If you want verification, go get a ir themometer from a shop and check the temp of your exhaust manifold while it is running. I bet it is near red hot at just 2k rpm..

So you are saying that the OP can open his hood while the car is sitting still and idling at 2k RPM, and his EM is going to be glowing red hot from being so lean?

 

[volkerding95GSX]

Go to any auto parts store and they will read your CEL for free. Before you spend any money or do anything else.

My first thought was also timing. Check your base timing with a light. A logger would be great to see about knock, but if you are already planning on getting v3 then just save that money to put towards link.

What octane gas are you using? When was the last time the fuel filter was changed?

Do you have an aftermarket boost gauge to confirm that you are only running 10 lbs of boost? I hope you aren't going by the stock gauge.

If you are truly only running 10 lbs of boost, then I don't think you are running too lean. The stock ECU runs super rich from the factory, so leaning it out a little by increasing airflow, should make it run better. To me it sounds like something else.

Also you said you fixed your boost leaks but I would recommend double checking it again. How mush PSI is it holding?

Hope this helps!

Yes it does help, thanks! To answer your questions I am using 93 octane pump gas. I do not know when the last time the fuel filter was changed, but I'll get on that (OEM is best I'll assume?) Yes I have an aftermarket mechanical boost gauge, so I do know it's 10 psi for sure.

And about the boost leaks: This is kinda rigged, but how I checked was by cutting a bicycle inner tube in half, tied it shut just before the stem, then stretched the other end around the turbo inlet. Then hand pumped it. I kept tightening the leaks until I could inflate the inner tube without it going flat anymore. Soooooo ya, idk exactly how much psi that would be.

I don't know off the top of my head how to check timing with a light, but I will search and look into it. Thanks!

 

[Colt4G63 also]

And about the boost leaks: This is kinda rigged, but how I checked was by cutting a bicycle inner tube in half, tied it shut just before the stem, then stretched the other end around the turbo inlet. Then hand pumped it. I kept tightening the leaks until I could inflate the inner tube without it going flat anymore. Soooooo ya, idk exactly how much psi that would be.

While that's very creative, it doesn't really give you more than a 1-2 psi test. You may be leaking so much boost that it just can't build more than ten psi.

 

[volkerding95GSX]

While that's very creative, it doesn't really give you more than a 1-2 psi test. You may be leaking so much boost that it just can't build more than ten psi.

Wellllllllllllllllllllllllllllllllllllllllllllllllllllll dang. Thanks for pointing that out though. Maybe I do just have a huge boost leak then... All the symptoms match up, right?

 

[9!'clipseDOHC]

Soooooo ya, idk exactly how much psi that would be.

Yes I have an aftermarket mechanical boost gauge, so I do know it's 10 psi for sure.

Look at your gauge! That will tell you how much your system is holding. Here is how to do one: http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/169435-boost-leak-test-how-boostpro-net-tester.html and here is how to make one: http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/209898-build-boost-leak-tester-your-to4e.html or like any one of these:

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[Calan]

While that's very creative, it doesn't really give you more than a 1-2 psi test. You may be leaking so much boost that it just can't build more than ten psi.

Wellllllllllllllllllllllllllllllllllllllllllllllllllllll dang. Thanks for pointing that out though. Maybe I do just have a huge boost leak then... All the symptoms match up, right?

I dunno. If it can hold a good-sized bulge in the inner tube indefinitely, it's probably not leaking too bad... at least not at 2-5 psi.

Do what Nate said. Look at your gauge!

 

[colbyc]

Haha some creativeness right there, I don't believe his problem is a boost leak(not saying he doesn't have any) I believe its pulling time as stated, did you ever get the ebc hooked back up correctly? Sale it and buy a halman pro mbc and be done with it. Get the CEL checked before all.