Poor performance with E316G setup, would appreciate ideas and suggestions.

[EdwardNorth]

Hey all,

For a couple of years now I have been running an EvoIII 16G setup on my Talon. While the performance was improved somewhat over the T-25, the results were minor and not at all what I expected. I have tried quite a few things to bring out the potential of my setup, but thus far have seen no improvements.

My biggest concern and mystery is, setting higher boost makes absolutely NO difference in performance. To clarify, if I have my boost set at 15 psi, the car performs exactly the same as if I set it up to 21+ or anywhere in between. Not a bit of improvement in acceleration or on the butt-dyno whatsoever. I feel that I have the necessary supporting mods to have very nice results at higher boost with this turbo, however I'm just not seeing much.

I have a couple ideas left of what the culprits might be, however I would greatly appreciate your input and suggestions on what to do to get the kind of performance I was expecting. Here is my current setup:

1997 Talon TSi AWD with roughly 21000 miles (yes, it's a very young and healthy car) 5-speed manual
- FP EvoIII 16G turbo ported
- Dejon Tool Super Big SMIC (rated to 400hp)
- FIC 650's
- Walbro 190 (not rewired)
- S-AFCII
- HKS Intake
- 3" downpipe, high-flow cat, and GReddy catback
- Ported exhaust manifold
- Hallman MBC
- Boost and EGT gauges
- Dejon Tool hard lower IC piping
- Hahn Racecraft Stage I upper IC pipe (the section with the BOV)
- GReddy type-S BOV
- AGX adjustable shocks
- Springs and Camber kit
- Short Shift kit
- Datalogger

I think that's about it. From what I have, the only thing I really think might be causing the problem is the SMIC. Dejon says it's rated to 400 HP, but despite all my best efforts I am not getting any better performance. I have logged and tuned with the datalogger and AFCII, and tried many different things to get at least SOME difference in performance at higher boost levels, but I am honestly stumped. Stumped, and pretty disappointed in my results.

The other things I don't have are a complete set of hardpipes, as the 2nd upper IC pipe (from the TB to the BOV pipe) is still the stock rubber-hose, and the intake tube is the stocker as well. Also, I am running the stock clutch and flywheel, but I don't think that is causing the issue.

For an example of the performance I am seeing here -- after nicely tuning the car and posting my timing curve on the forums, verifying that it looked good with other people, I tried timing a 2nd gear pull, punching it at 3500 RPM and going to redline at 7000. It took me almost 5 seconds! This is my result whether I'm running 15-16 psi, or 21-22 psi. The car should be MUCH faster than this.

I usually run 94 octane, but have also tried 100 race gas with the same results.

So I suppose my biggest questions are:

1) Would upgrading this super SMIC to an FMIC make the difference and give me my lost power?
2) Does my current lack of full hard IC piping and hard Intake piping have anything to do with this issue?
3) Is there any chance I have a boost leak somewhere that is robbing me of this power? The boost gauge does seem to indicate perfectly, if it matters.

Thank you for taking the time to read this, and I hope you guys can help me figure out what to do.

 

[romeen]

Boost Leak Test all the way!

It sounds like you have done your homework and your setup should definitely pull much harder than the T25. A FMIC should definitely net you some power but taking care of the probable boost leaks that you have should take precedence over all else right now. The hard IC piping is a good idea but it's not the type of thing that will give obvious gains that you can feel.

You may also want to consider doing a compression test and checking for pre-turbo exhaust leaks.

BTW, I have an EVO 3 with an upgraded SMIC. I can usually tell when a boost leak pops up. The car just loses it's zing and I may smell fuel in the exhaust. My $17 dollar boost leak tester is probably the single best investment I have made towards my car. Even with my side mount at 18 psi I can light up the tires far into 2nd gear.

 

[gsxtacy]

I never truely realized how crappy pump was till I ran some 100% VP 116 through the tank.

I know you said you tried 100 octane, but try some VP 116...it is awesome

 

[pboglio]

1) Boost leak check for sure.
2) Maybe check wastegate actuator preload, add washers if necessary.
3) Check exhaust manifold/head and manifold/turbine housing exhaust leaks. New gaskets and resurfacing of the exhaust manifold flange surface and turbine housing surface will guarantee no leaks if properly torqued down.
4) Check cylinder leak down, I prefer it over a compression check.
5) Replace the stock 2g intake pipe with at least some kind of cheap elbow replacement like RRE or Dejon sells, worth about a 2 psi increase in boost and much better response.
6) Not sure what your timing curves are, but 2g's have a crappy stock timing curve.
7) Maybe they cut your flow divider off your exhaust manifold when they ported it, that'll kill your power, happened to me once.
8) Swap to new spark plugs and wires, also a power killer if they are bad.
9) A/F ratio being off, too lean or rich is gonna make the car slower.
10) Knock retard could also slow the car down, see above.
11) HKS Intake. If its foam and dirty, your gonna notice an increase SOTP if you swap to a new K&N. Been there before too.
12) Drop the cat and try a test pipe to see what happens, might be clogged.
13) All time favorite. Loose throttle cable. That'll really make the car feel slow. Check the slack and make sure its tight by pushing on it sideways.

 

[UofACATS]

Do you have a wideband?

 

[PieEyedPiper]

Can you post some logs?

 

[turbosax2]

Boost Leak Test all the way!

+1. Also, rewire that fuel pump. It's cheap and easy.

 

[EdwardNorth]

Thanks for the input.

I'm second guessing myself on this whole situation right now. I think I was wrong about the 5 second 3500-7000 pull, and if anything, I think I may have been running a bit too lean. I referenced my old logs and made some adjustments to the AFC this morning and did another timed pull on my way to work, only at 16 psi, and it took me 3.5 seconds punching it at 3500 to redline. It even bogged a tad at first, so that aside, it probably only took a hair over 3 seconds. Probably lean it up a bit at the low end to compensate.

This seems about right to me, being AWD and punching it from a roll, roughly 3 seconds from 30-62 mph at only 16 psi. I'll up the boost before I leave work and try another pull and post the timed results later.

I'll definately do a boost leak test either way.

 

[pboglio]

My car does 3500-7000 rpm 2nd gear in 2.97 seconds on 19 psi and it is dialed in to a "t". If your pulling 3.5 seconds or so on 16 psi then like you said you really don't have a power problem for your mods.

Bogging could either be a/f ratio or low ignition timing or injector dead time. A couple keystroke adjustments on DSMLink cures that problem pretty quickly on my car. Don't know what can be done with an AFC. Good luck.

 

[EdwardNorth]

My car does 3500-7000 rpm 2nd gear in 2.97 seconds on 19 psi and it is dialed in to a "t". If your pulling 3.5 seconds or so on 16 psi then like you said you really don't have a power problem for your mods.

Bogging could either be a/f ratio or low ignition timing or injector dead time. A couple keystroke adjustments on DSMLink cures that problem pretty quickly on my car. Don't know what can be done with an AFC. Good luck.

Awesome. That information helps me out greatly, thanks!

 

[Thomas91169]

Boost Leaks, Exhaust leaks (pre turbo), and compression all are major players. Could be a ignition or timing related issue as well.

 

[EdwardNorth]

Well I did a few more 2nd gear pulls after work. Temps were warmer outside than they were this morning, but I first set the boost up to 18psi and did 3500-7000 in 3.37 seconds, so a definate improvement there. I then enriched it 2 degrees across the board and the time dropped to 3.78, so definately running rich. I set it back to my previous settings and leaned it 1 degree extra across the board, then set the boost to about 19-20 psi and I did 3500-7100+ (let off too late), that run took 3.31 seconds. Since I went past 7000 by 100 or so, I calculated 3500-7000 based on my time and found that it would be roughly 3.2 seconds.

I think my butt-dyno is in need of an overhaul, since the car doesn't feel any different between the boost settings but the times are definately improving. I will still be doing a boost leak test, but I'm thinking things are probably fine now.

Thanks again for the input!

 

[silvah_gsx]

I think my butt-dyno is in need of an overhaul, since the car doesn't feel any different between the boost settings but the times are definately improving.

You're just getting too used to your car's power. This is a problem though, because it means only one thing: you need more power!

And the boost leak test should show you something. You should be able to hold the pressure for quite a while. For reference, you should be able to hold most of the pressure for close to a minute, although that's subjective. Good luck!

 

[EdwardNorth]

You're just getting too used to your car's power. This is a problem though, because it means only one thing: you need more power!

And the boost leak test should show you something. You should be able to hold the pressure for quite a while. For reference, you should be able to hold most of the pressure for close to a minute, although that's subjective. Good luck!

Thanks!