Stage 2 PCM with DSP question - SRT Forums

solarsrt4tn · 07-02-2009, 07:25 PM

Would I be better off using the DSP on a stock pcm? Only reason I'm asking is cause it seems like my car is extremely slow for what it has done. I only trap 80-83 mph in the 1/8, while people with similar mods have been trapping 85-87.

I have a pretty much every bolt on for the stock turbo

FM WGA 22psi Spike hold 16
Godspeed FMIC
DSP
3" o2 housing
3" needswings downpipe with cutout
Mopar catback Exhaust
K&N Intake
Complete stage 2 kit
MSD Wires
Exhaust Depot coldside pipe with HKS BOV
Samco hotside pipe
MMIs
Solid LCA bushings
ACT street disc clutch

I had a shitty $20 catchcan that I removed because it was leaking and there was hardly ever anything in it. However, I've had the intercooler off and cleaned it out since I've removed it, haven't had a chance to replace the catch can yet.

What could be causing me to trap so low? Compression on the motor seems fine, IIRC 150 across the board. I do have a very small boost leak coming from the coldside pipe but my car still held 22psi fine when I checked it even with that leaking. Any ideas what could be causing this? Is it just me needing to have the car tuned or what? It seems like I should be doing a lot better...the only difference between my car and the cars that I'm comparing mine to is that they use an SAFC to tune with..hell one of them it wasn't even hooked up right and he still ran better than me..it's almost got me convinced to switch over to that and try it. Any ideas?

hyypro · 07-02-2009, 09:12 PM

First thing would be the boost leak. ANY boost leak will affect performance at least a little. The second would be your tune. With this car timing plays a big role. Also, I wouldn't recommend boosting 22 psi unless you have water/methanol injection. Lastly would be your driving skills. Have you tried shifting at different RPMs and whatnot? Hope this helps

solarsrt4tn · 07-02-2009, 10:18 PM

Quote: Originally Posted by hyypro

First thing would be the boost leak. ANY boost leak will affect performance at least a little. The second would be your tune. With this car timing plays a big role. Also, I wouldn't recommend boosting 22 psi unless you have water/methanol injection. Lastly would be your driving skills. Have you tried shifting at different RPMs and whatnot? Hope this helps

I understand that about the boost leak, I'm going to have to replace that coupler. Most of the time 22psi had a gallon of 110 mixed in with it. Maybe I just need to adjust my tune. I guess I'll retune for pump gas on 20 psi and adjust the timing some. If I get to a point where I need to choose between timing or a leaner afr which should I go with? Shouldn't my afr be around 11.5?

Also though what I don't understand is my buddies that are trapping higher are spiking 22 to 23 psi with no adjustments to timing on 93 octane and are barely getting any knock (1-2 counts). Why would their car be so different than mine?

And yes I've tried shifting at different times lol and even drag radials. I just spun through first on the radials, shifted at 5500 then at 5800 out of 2nd. Could be my tracks mph calculation is off though, it always seems like I'm going 85 when I cross the line but I never register that fast.

goats srt · 07-02-2009, 10:22 PM

add timing cause the timing tables on a S2 are low i had to add alot cause there so low

solarsrt4tn · 07-03-2009, 05:39 AM

Quote: Originally Posted by goats srt

add timing cause the timing tables on a S2 are low i had to add alot cause there so low

To all RPM ranges? I've added like 2 degrees between 2-4k but any higher rpms than that it seems like I get knock. How much timing did you add?

goats srt · 07-03-2009, 07:54 AM

Quote: Originally Posted by solarsrt4tn

To all RPM ranges? I've added like 2 degrees between 2-4k but any higher rpms than that it seems like I get knock. How much timing did you add?

Where's your timing at now

solarsrt4tn · 07-03-2009, 04:05 PM

not sure where my timing is at. I'll take a log in a few and post it up.

solarsrt4tn · 07-03-2009, 05:25 PM

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Not sure where that 3 counts of knock came from. Other night at the track it was fine on 93 octane only getting 1 count max then I added a gallon of 110 just to get rid of that and it was fine, now it's up to 3.

Also I noticed my timing seemed extremely low for some reason..only 25 degrees around 6k. I usually get about 28 or 29 by then..I'm about to fix that boost leak now and I'll mess with the tune some more later I guess.

goats srt · 07-03-2009, 05:34 PM

Yea that's alittle low manily for a stock turbo try new NGK plugs helps with knock and add timing or get meth and add boat load of timing

solarsrt4tn · 07-03-2009, 11:35 PM

Quote: Originally Posted by goats srt

Yea that's alittle low manily for a stock turbo try new NGK plugs helps with knock and add timing or get meth and add boat load of timing

are they one or two steps colder? the ones modern sells?

rrmike1 · 07-04-2009, 09:29 AM

Modern sells stock heat range and 1 step colder.

goats srt · 07-04-2009, 09:33 AM

U can also get the 4306 at napa

EvilTwinSRT · 07-04-2009, 09:57 AM

I don't see a wideband listed on your mods. Do you have one? If so whats your A/F's? If you don't get one. Stage 2's run very rich and you may just need to lean it out.

solarsrt4tn · 07-04-2009, 11:01 AM

I guess ill be orfering ngk iridiums one step colder from modern on monday. are there any side effects to running a step colder plug?

and yes i do have a wideband. my afr is 11.6 at about 3500 then 11.4 til 5k to where it drops to 10.8 by redline. i thought leaving it rich like that would help with knock...guess i was wrong lol.