First Dyno Run.

[Trigger Jack]

Just had my GST dynoed, mainly to get a baseline, but also to see what the few mods I have done to it would net. For those who don't want to read my car profile, it's an Injen intake, 2.5 catback exhaust, Big T28 from AGP at 9psi currently, 1g bov, and that's about it. Dyno put out 174.16 hp, 175.77tq on a Dynojet dynamometer. 70 Degrees, 26% humidity, SAE 0.99, if that matters any. Granted, I'm running only 9psi, so I guess the only thing I'm wondering really, for those who have done baselines, is if I'm in the right area for the minor things I've done so far? Next on the list is a mbc, going to have that set at 12psi, but I'm wondering if that will really bring me up that much in hp? I've tried searching to see changes in hp from 9 - 12 or so psi, but haven't found a link yet that answers the question. I'm fairly pleased with the car so far, but if I'm missing something drastic, I'd appreciate a nudge in the right direction. Thanks.


Ps....as for the 9psi, that's what it was reading off my boost gauge, which, if anyone has read my post about the t28 install....was hooked up wrong. It may be running more than that, I know it's a problem i need to address first.

 

[buscodsm]

For each pound of boost it usually adds 7-10 horsies (at least thats what i have been told)

 

[webshell]

I thought a stock GST usually pulled numbers like that if not higher..... check for boost leaks. and get a mbc quick they r like 15 bucks.

 

[Sk8er07999]

Should yield a real nice gain. I would say at least 20 whp. Go get that mbc!

 

[2gGSX]

More fuel upgrades are what will really open that turbo up. The next mods you should be considering are pump/logger/afc/injectors.

 

[Trigger Jack]

Already got the pump (not installed yet) and a logger, mbc is now on the way, as well as a proper install of my boost gauge. If I intend to only run at MOST around 14psi, are all the fuel upgrades entirely neccesary though? I thought the general idea was 15psi+ required those. I'm not looking to run anything really high, it's not going to be a track car, or even an amazingly fast street car. About 220-230 whp is my goal, figured it should be easily reachable with a Big T28..... I was expecting to be a bit higher than I am now though. This weekend, I'll have the mbc/boost gauge in, turn it up a few notches, and get it dynoed again. If anyone has any other suggestions, I'd be glad to hear them.

Also....i'm confused on one thing. The stock whp for an auto GST is what? I keep seeing 180 on here, but I get around 160 if I calculate it on a 1/4 calculator, and Import Tuner dynoed a mostly stock GST at 165.....Even calculating 205hp by a 20% loss, which as far as I know, is about right...puts you at 164....

 

[scottsee]

there is no reasion whit what you have now, that using a pocket logger & safc with 190 & 550's you cant be at or around 250-275whp!

 

[Trigger Jack]

250-275 with my mods (and including the ones you mentioned)? Assuming I run what psi? This has to stay my daily driver, so i have to maintain some amount of gas mileage out of the whole ordeal, as well.

 

[Sk8er07999]

Yeah man I don't see why you would need fuel mods to support that t28. Hook up the mbc and make a few pulls carefully watching the logger and you will be pleased with the results.

 

[90CherryTSI]

you can net your desired HP off a T-25.....you got a t28? No boost gauge, no mbc, I'm seriously HOPING you just bought this car and it came with that......you have no gauge, no mbc, nothing except 2.5 exhaust and intake, yet a t-28?

 

[scottsee]

do youself a favor and buy a boost gauge, mbc and turn it up! you mignt or might not need new injectors and fuel pump, but that depends on how high you turn it up. anything under 14-15psi you should be fine. but im promising you once you do it, you'll want to turn it up higher. and if you do you'll 99% hit fuel cut and need to get what i previously stated..

 

[pacent]

Those numbers sound a little low. I dyno'ed my car on a dynojet back in the fall with the stock t25 turbo @ 15psi, turbo back exhaust + hi flow cat, injen intake, upper IC piping + Greddy BOV, and heavy (heavier than stock at least) 17" wheels. Ambient temperature was right around 45-50 degrees IIRC and I was putting out 204whp and 213lb/ft torque.

 

[heavypedalmuzic]

get a boost controller, and finish up your exhaust with a 2.5 DP, no cat or high flow one and maybe an o2 housing. set the controller to 14 psi, then see where you're at that point.

if you want more, then get the 190 fp and an afc and up the boost to 15-16 psi and im pretty sure you'll be at your goal.

 

[Trigger Jack]

Well, I just had the boost gauge properly installed. Due to the leak in the setup of my last one, it was giving me a false reading. I am, in fact, at 12psi.....but with the stock injectors and no fuel control.....running lean is probably killing my horsepower a bit, i'm guessing? I still would have thought that at 12 psi, i would have seen at least a bit more difference over the t25.....

 

[Injected]

A lot of these replies are fairly misleading, especially about adding fuel injectors, a pump etc. I know a lot has been touched on, but something’s need to be reiterated and some new things need to be brought to light and some corrected. If you read the Import Tuner Power Pages GST article, then there are some other things that you should realize. The path to power in the DSM world was well pioneered in the early 90's and again in the mid 90's for the 2nd gen. cars. Follow this path and DO NOT deviate from it. The order of some of the first is sometimes not so incredibly importanct, but if you read about any project car that is done professionally, you will notice that the upgrades complement each other and do not skip steps. Before a turbo upgrade, you should have replaced at least 85% of your intake tract and exhaust system. You should never start to significantly increase the power of your car without the ability to monitor your car’s performance. A boost gauge is great for a first mod. You have the Injen intake. Great. You’ve upgraded your BOV, but what about the crappy intercooler piping, including a throttle body elbow, may as well and since an aftermarket pipe will allow you to bolt your BOV on a flange instead of sticking it into the pipe, flow will be increased nicely. No boost controller, big problem. In that very same Project Eclipse GST, IT reported this for the Turbo XS MBC:

Since max torque is made in the mid-rpm range, this upgrade did wonders for our torque curve, picking up as much as 50 lb-ft of torque.

This is because the wastegate is held shut while the turbo spools. Next is the exhaust side. You have a cat-back. Okay, but it’s only 2.5” and this is probably fine for now and your goals and 3” wouldn’t make “much” of a difference. Next should have been a down pipe. The stocker is crap. A high flow cat or strait pipe would also be a great idea while you’re down there. These make a significant difference in power and torque. By now you can run ~14psi on the T-25 all day long with the stock fuel system though the T-25 is outside of its efficient area. NOW you should consider a larger turbo to produce the same amount of boost and operate more efficiently. At this point you should be running beyond your 220whp goal. You will need a new clutch to hold the power…might as well get a light flywheel…the list goes on as to where you will go from here. At this point you need to reassess the situation. You have a larger turbo and need to bring your car up to par to take advantage of it. All of the posts about more fuel…There is no need to add more fuel at his level of boost. If anything, he should lean out the top end because he is running the stock fuel map (rich). With an AFC, etc. he could do this easily. Another thing that is never emphasized is resetting your car in ‘learn’ mode. Disconnect your battery for a while (15-20 min.), and go do 3-4 3rd gear pulls. This will allow the car to accommodate for the different airflow than stock.

 

[ozzeran]

Nice write up.

A lot of these replies are fairly misleading, especially about adding fuel injectors, a pump etc. I know a lot has been touched on, but something’s need to be reiterated and some new things need to be brought to light and some corrected. If you read the Import Tuner Power Pages GST article, then there are some other things that you should realize. The path to power in the DSM world was well pioneered in the early 90's and again in the mid 90's for the 2nd gen. cars. Follow this path and DO NOT deviate from it. The order of some of the first is sometimes not so incredibly importanct, but if you read about any project car that is done professionally, you will notice that the upgrades complement each other and do not skip steps. Before a turbo upgrade, you should have replaced at least 85% of your intake tract and exhaust system. You should never start to significantly increase the power of your car without the ability to monitor your car’s performance. A boost gauge is great for a first mod. You have the Injen intake. Great. You’ve upgraded your BOV, but what about the crappy intercooler piping, including a throttle body elbow, may as well and since an aftermarket pipe will allow you to bolt your BOV on a flange instead of sticking it into the pipe, flow will be increased nicely. No boost controller, big problem. In that very same Project Eclipse GST, IT reported this for the Turbo XS MBC: This is because the wastegate is held shut while the turbo spools. Next is the exhaust side. You have a cat-back. Okay, but it’s only 2.5” and this is probably fine for now and your goals and 3” wouldn’t make “much” of a difference. Next should have been a down pipe. The stocker is crap. A high flow cat or strait pipe would also be a great idea while you’re down there. These make a significant difference in power and torque. By now you can run ~14psi on the T-25 all day long with the stock fuel system though the T-25 is outside of its efficient area. NOW you should consider a larger turbo to produce the same amount of boost and operate more efficiently. At this point you should be running beyond your 220whp goal. You will need a new clutch to hold the power…might as well get a light flywheel…the list goes on as to where you will go from here. At this point you need to reassess the situation. You have a larger turbo and need to bring your car up to par to take advantage of it. All of the posts about more fuel…There is no need to add more fuel at his level of boost. If anything, he should lean out the top end because he is running the stock fuel map (rich). With an AFC, etc. he could do this easily. Another thing that is never emphasized is resetting your car in ‘learn’ mode. Disconnect your battery for a while (15-20 min.), and go do 3-4 3rd gear pulls. This will allow the car to accommodate for the different airflow than stock.

 

[midnght]

If you read the Import Tuner Power Pages GST article, then there are some other things that you should realize.

That Magazine is notorious for misprints and left out addage.

including a throttle body elbow, may as well and since an aftermarket pipe will allow you to bolt your BOV on a flange instead of sticking it into the pipe, flow will be increased nicely.

He has a 2G. The eblow is fine and flow is good enough to make alot more than 500whp, which he seems to not be in a hurry to get to....ever.

You should never start to significantly increase the power of your car without the ability to monitor your car’s performance. A boost gauge is great for a first mod.

Get yourself a pocketlogger aswell. I do not recommend the novice to tune without it.

Next is the exhaust side. You have a cat-back. Okay, but it’s only 2.5” and this is probably fine for now and your goals and 3” wouldn’t make “much” of a difference. Next should have been a down pipe. The stocker is crap. A high flow cat or strait pipe would also be a great idea while you’re down there. These make a significant difference in power and torque. By now you can run ~14psi on the T-25 all day long with the stock fuel system though the T-25 is outside of its efficient area. NOW you should consider a larger turbo to produce the same amount of boost and operate more efficiently. At this point you should be running beyond your 220whp goal.

I made over the 220whp mark with the stock exhaust. I will grant you the Intercooler piping is horrid. The exhaust is needed for more flow after an upgrade. But he is ok for now. Also, the stock fuel system will run diffent on different cars. I ran 19psi on my t25 for months. Never stuttered or cut. Different strokes for different folks is all.

might as well get a light flywheel...

I do not suggest it. Why do most people do it anyway? Misconception is that it builds boost faster. In most cases, many that are fast enough hate the lighten fly because it can drop you out of your powerband pretty quick. Also hard on the guys running S-AFC's. It is a pain in the ass for most to keep the car from stalling.

. If anything, he should lean out the top end because he is running the stock fuel map (rich). With an AFC, etc. he could do this easily.

I disagree. He is flowing more air even at 9psi on the top end than a T25.

Disconnect your battery for a while (15-20 min.), and go do 3-4 3rd gear pulls. This will allow the car to accommodate for the different airflow than stock.

I agree. Might take a bit more than 3-4 pulls though.



Overall, great response. I am not downing you, just stating my personal experience and ideas.

 

[Injected]

First of all, I would like to say thanks Midnght for your well written response.

That Magazine is notorious for misprints and left out addage.

I know this. I don't personally read this magazine because of this and its focus on the 'scene' rather than the cars. I was implying that if he is using this as a source, then he should realize a few more things from reading it.

He has a 2G. The eblow is fine and flow is good enough to make alot more than 500whp, which he seems to not be in a hurry to get to....ever.

Your right (I don't know about 500whp), but I was also meaning that the intercooler pipe should run to the throttle body elbow. A lot of people will contend that the sharp bend creates a small lag in throttle response (SCC) and that upgrading it improved this, which goes with his goals. I'll attatch a pic of the stock intercooler piping on a 2g so others can see what I was talking about as well as what you are.

I made over the 220whp mark with the stock exhaust. I will grant you the Intercooler piping is horrid. The exhaust is needed for more flow after an upgrade. But he is ok for now. Also, the stock fuel system will run diffent on different cars. I ran 19psi on my t25 for months. Never stuttered or cut. Different strokes for different folks is all.

You will notice a huge increase in response, drivability, and torque from upgrading the exhaust though and these are his goals. With just a BOV the T-25 can spike to 19 with all else remaining stock (my experience).

I do not suggest it. Why do most people do it anyway? Misconception is that it builds boost faster. In most cases, many that are fast enough hate the lighten fly because it can drop you out of your powerband pretty quick. Also hard on the guys running S-AFC's. It is a pain in the ass for most to keep the car from stalling.

This is a well contend topic in the aftermarket community. I would suggest anyone who is considering this as an upgrade to talk to a lot of people before upgrading and make your own decision. I'm not the only one who will contend that a lightened flywheel is good. Here is what Road///Race Engineering says about thier flywheels:

Lots of people freak out about any "theoretical" drivability issues. They are wrong, it's all good. They are not too light for street use, they won't break apart, they are stepped correctly for ACT and CFDF clutches, On a 80 hp honda you could go too light, but not on anything with enough power to pull the skin off pudding. You will have to compensate a little in your launching technique, a little higher launch rpm will be necessary. Your shifts will be better with the engine rpm now better matching the next gear. These are SFI certified.

Which one do you want? Aluminum, XACT or lightened stocker? They are all good. Get the lightest one that you are comfortable with and that your budget allows.

I disagree. He is flowing more air even at 9psi on the top end than a T25.

He is flowing more air than stock but this isn't correct. These cars are MAS not MAP (like a Honda). The car will compensate to run richer fuel maps even as airflow is increased. That is why you reset the car as you and I agree you should, so the ECU will learn about the greater flow more quickly and compensate. It will still run rich though as it will just add more fuel to compensate.

Overall, great response. I am not downing you, just stating my personal experience and ideas.

Thanks, it's all good. I just hope that through disagreements people will learn and not just argue.

 

[FourG63 97GST]

I suggest more fuel and tuning.
when I had the stock fuel with my T28, I made 206hp/212tq @ 15psi, my a/f was 12.1 so I didn't think I needed fuel either. well I got a walbro 190 anyway, dynoed again @ 15psi and made 215hp/234tq.it though it was a bit rich uptop though, lil under 11.1 a/f. added the afc lean it out inthe higher rpms where it was rich then I got 245hp/234tq @ 17psi........moral. tuning is beautiful

 

[midnght]

First of all, I would like to say thanks Midnght for your well written response.
Your right (I don't know about 500whp), but I was also meaning that the intercooler pipe should run to the throttle body elbow. A lot of people will contend that the sharp bend creates a small lag in throttle response (SCC) and that upgrading it improved this, which goes with his goals. I'll attatch a pic of the stock intercooler piping on a 2g so others can see what I was talking about as well as what you are.


You will notice a huge increase in response, drivability, and torque from upgrading the exhaust though and these are his goals. With just a BOV the T-25 can spike to 19 with all else remaining stock (my experience).

This is a well contend topic in the aftermarket community. I would suggest anyone who is considering this as an upgrade to talk to a lot of people before upgrading and make your own decision. I'm not the only one who will contend that a lightened flywheel is good. Here is what Road///Race Engineering says about thier flywheels:

He is flowing more air than stock but this isn't correct. These cars are MAS not MAP (like a Honda). The car will compensate to run richer fuel maps even as airflow is increased. That is why you reset the car as you and I agree you should, so the ECU will learn about the greater flow more quickly and compensate. It will still run rich though as it will just add more fuel to compensate.

Thanks, it's all good. I just hope that through disagreements people will learn and not just argue.

All good man! That is what opinions and experience on different things is awesome. Just goes to show what is good on one is not on another.



As described in the post above he will eventually have trouble. Not at 9psi, but with the new turbo and multiple things that can cause spikes or lean situations I just don't suggest the stock fuel injectors. I guess it also depends on what turbo or model T28 he is running. There are WAAAAAAAAY too many to get an accurate lock on what to do. Only graphs and meters will tell, .


The flywheel is also, as you stated, a user friendly type situation. Some like (I DO :laugh: ) some do not, just a personal preference is all. Then you get into which one and such to use.

I agree that the more direct route the air gets to the engine the better it is. Just that the 2G elbow is best stock wise and I have seen the 527whp GT35r equiped DSM throw down some serious power with it. SOrt of like the intake pipe. I have dynoed 300+whp with the stock accordian. Is it the best, na. I just don't justify the $150 for a 4-5hp it might give me. I have for now a hard pipe that is clamped to the accordian top section directly after the dumptube. It works great.







Haven't been on the site in awhile, just got burned out with the same stuff I guess. It is nice to be back.

 

[Trigger Jack]

I'd really like to thank all of you, for the posts and advice. As was mentioned, the 500 horsepower goal, is not a personal goal of mine. I have pretty mild goals in comparison to some of the patrons here. I also am fairly new to DSMs, so I'm trying to learn as much as I can without running down the wrong road too often. I do have a printed copy of the stages of upgrade, the turbo just happened to come along by good timing and circumstance. Wasn't about to pass up the oppurtunity, so I grabbed it, and am doing my best to catch up the rest of the car on my limited funds. As far as the Import Tuner thing........I just did a search on google for a stock GST dyno, and that was one of the links I found that actually had a picture of the dyno to back up the stated figures. I also do have a logger, pc based, not pocketlogger type, that allows me to export everything into graphs with time stamps and other things.(www.obddiagnostics.com) But without tuning, I know it's really just a lot of numbers that I'm compiling and not doing anything with, currently.
Anyway, just wanted to throw that in, my word of thanks to everyone giving my situation some time and thought, so it helps me in the long run. It's very appreciated.



Edit: If someone could tell me what the stock fuel trim at idle is supposed to be...that'd be great, since I can't seem to find it in the search. Everytime I log at idle, I get 5.5% stft, and 12.5 ltft. Usually on the road, it drops to 0 stft, with 17 or so lftf I know you can usually add the two together, and that gives you the trim, which would put me at 17-18....but knowing what stock is, would be nice.

 

[BOBS90TURBO]

Hey, just to give you another base line on another 2g gst (96 w/93k on it).

Import Tuner mag March of 05 issue power pages dynoed a complete stock 2g, the baseline was 166HP 177TQ.

After injen intake/filter 185hp 196tq.

After RS*R cat back 194hp 203tq.

After RS*R Down pipe 202hp 206tq.

 

[Trigger Jack]

Anyone have the stock fuel trim number?
Bobs90turbo, thanks for the extra numbers, looks like 166whp is about right....but...19hp gain with just intake? I've got an injen intake and I know i'm not looking at those kinds of numbers, . Unless it was a different type or something.