Take a look at my Dyno sheet (T25)

[Chris95GST]

I got my car dynoed a couple of months ago and put down some decent numbers but they really drop off in the higher RPMs. My mods are in my profile and in the link in my sig. I want some opinions on how do tune it a little. Right now its set up to RRE's sugestion for 550s but my O2 volts never dip below .93 and go up to .96+ The run was @20 PSI which it only spiked to and was open downpipe because my exhaust is coming a part and it was one run for $20. Do you think I should be safe tunning with out an EGT guage or logger? I really want to get thoose two items but I decided I'm just going to get DSMlink this summer because I saw it in action and its ALOT better then the SAFC. I also plan on getting a FPR next. So do you guys think it would be relativly safe to lean it out a little at the top (it goes to .96+ in the hight RPMS).? Thanks for any advice.

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[2g6boltTsi]

Actually anything above 15.5 psi on a t-25 is way out of it's efficency range, you'd probably make the same power, if not more by running 16psi. and if you are going to stick with a t-25 I wouldn't Worry about getting the egt, just don't get stupid with it i.e. leaning it out 15% in all ranges, and you should be fine.

 

[miteclgst]

I believe that your T25 is the reason that your horsepower is dropping off after 4K. The T25 will only run up to 5K or so and then it dies out real quick, If you say that you were running 20psi on the dyno, that probably only occurred from about 2800 (full spool up) to 4K when it starts its decline. You can ask anyone here on the forums you can set the T25 to 30psi if you want but it won't do anthing more then hold it for a little bit and then drop to 10psi. Watch your gauge next time and you will see this happen, I think a lot of people will agree with me that your best bet to get rid of that drop off is to upgrade to a bigger turbo. There are plenty of turbos out there, 16G Evo III 16G, 20G that will allow you to make good power and won't drop off like the T25 does. I currently own a Evo III 16G and that thing will hold 20psi all day long.
Your best WOT 02 voltage is around .94 on the 2g. If you add more fuel you will not gain anymore power. I wouldn't tune at all with out at least the EGT gauge. Tuning without it is like tuning with your eyes closed.

 

[Blk_99gst]

Wow, 210 with a t25; not bad at all.

I say that's great to be holding out for dsmlink, but if you truely were going to do that, then you should not have gotten the safc. You could have saved 200 or 300 bucks and put that towards dsmlink. Also you mention o2 voltages, but if you're not reading them off of a pocketlogger, then you must have done the blue wire mod with the safc. That, in my opinion is very bad. It can change the voltage on the o2 wire quite a bit. I'll cut and paste a paragraph about it below.

As far as what I'd recommend. In my opinion, the best thing to do would be to put the 450's back in and set the safc to zero or just remove it. Give control back to the ecu. Or, keep the safc and 550's in, but find another dsmer with a logger and set the car up, but a little on the conservative/rich side. Because when weather changes, so will the tuning.

Blue Wire Mod Explained
Most voltmeters don't impose any effect on a circuit
because they are in the millions of ohms of resistance
range. If you want to meausure a the voltage of a low
resistance circuit this high resistance voltmeter is
not neccessary, and perhaps that was the design of the
AFC's blue wire mod. I'm not sure what that wire is
supposed to be used for anyway. For the o2 sensor, too
much current flows through the AFC, essentially
putting a load on the o2 sensor itself.

You might see a variation between the pocketlogger and
the afc, but more importantly, you will see a huge
difference if you put a switch on the blue wire. on
Watch the logger, and toggle the switch. Your o2's
will suddenly jump up to where they are supposed to
be. On my 420a NT talon the blue wire dropped the o2's
from .98 to .92 and caused the car to run extremely
rich in closed loop mode (with SAFC zeroed out).

 

[Chris95GST]

I firgured it was just the T25 droping off that caused the big dip. Do you think with better tunning the torque won't dip off so soon? When I watch the boost gauge it will spike to 20PSI for a second or to then die off to 13ish. I have it set to 16PSI for normal driving though.

As for the SAFC, It was on the car when I bought it because and I thought it would be more then enough but I only knew little of DSMs and didn't see the greatness that is DSMlink. Plus I have a EPROM ECU and can sell the SAFC so the cost won't be too bad.

I guess I'll just wait till I get an EGT guage and DSMlink before I start to tune more. I just wanted some more HP to tie me over for a little bit. I don't plan on keeping the T25 to much longer I just want to max out its potential and then get an AGP turbo kit.

 

[CanadianTSi]

Running the T-25 @ 15psi with the stock Fuel Pump and stock injectors I'm leaning it out 5% up top and my o2's are still around .95 ish

 

[kpt4321]

Don't try to tune without DSMLink or a logger, you just shooting yourself in the foot.

Tell your dyno shop to scale the damned torque and horsepower lines correctly, so they match up!

Those numbers are not too bad, but I bet you have some ground to gain with tuning.

 

[pickens]

my 2g seems to like its o2 voltage around .98. Thats on 91 pump though. At .96 timing gets dropped a little, and at .94 it runs like poo.

 

[Trctnless]

http://carolinadsm.com/gallery/AutoX?page=2

hmm. You got alota fuel you can throw at that little turbo. You have a 1G head and all that fuel and control, 209 would indicate your missing out on some power. I did 209 on on a 2g with Stock Fuel/DP, BPU's and the addition of the MKIV SMIC. I would expect had I had a 1G head (flow wise) would've laid down some more HP. See the dyno sheet of my T25 before and after the SUpra Intercooler. It'll smooth out and pick up your power band I guarantee it. I added 32Hp adding a SMIC w/a T25. I'll bet you could see 230+ HP adding a good IC to your set up. (I didn't see one in your mod list)

Seriously though. don't tune Blind... A Logger and an EGT will help you squeeze more out of it safley. You'll find more timing and power if you lean it out up Top (till you knock of course). Dsm link Rules.

Then you'll give up and a Big 28 like I did