Stage II Wastegate

[neverdone]

Old school TD'er here, I just picked up an 04 SRT-4 and I have been doing a lot of net surfing for info. The previous owner has installed a Stage I PCM, along with the Stage II WGA. The car runs really strong but I am concerned b/c @ WOT the boost spikes to 20psi if not more then settles back to 15 psi. It doesn't act funny or anything I was wondering if I should adjust it back a little and if I did would it affect the 15psi it settles to? My Shelby Z on a 16 psi computer would just boost to a solid 16 psi so these spikes are new to me. I can't believe how fast the boost comes on compared to my old Z. Thanks for any info.

Joey

[oklamopar]

is it running off computer controlled boost or is it had the vacuum lines messed with?
Ive seen and talked to allot of NSRT-4 owners running that set up and it seems to my memory that is normal with the S2 waste-gate.
I'm using the AGP waste-gate and i boost 18psi falling to 15 at red line. I'm also stage 1 but with vacuum line mod.
more about the mod here.
SRT-4 mod Q's newb to srt's here

[BobsBlackACR]

I think that is very typical for the mods listed. Most see a fade of boost of 4-6psi unless they have an upgraded WGA like an AGP for example. Then more boost can be seen at redline,

[neverdone]

It's running off the computer as far as I know the vaccuum lines have not been messed with. I guess another way to pose the question is does the Stage I pcm provide enough fuel to keep the A/F ratio healthy for those 20 psi boost spikes? It only sees that much boost for a split second but then again that's all it takes to grenade it.

[oklamopar]

they say 15psi max on stage 1 without map clamp or some sort of fuel trimmer.
thats why i do 18 and let it fall. im still a little rich [12's] but better safe than BOOM!!!

[neverdone]

Quote:

Originally Posted by oklamopar they say 15psi max on stage 1 without map clamp or some sort of fuel trimmer. thats why i do 18 and let it fall. im still a little rich [12's] but better safe than BOOM!!!

That's what I figured, I said to heck with it and pulled the stage II wga and put the stocker back on. It's still fun to drive and no worries afterall this is my DD.

[neverdone]

Quote:

Originally Posted by oklamopar is it running off computer controlled boost or is it had the vacuum lines messed with? Ive seen and talked to allot of NSRT-4 owners running that set up and it seems to my memory that is normal with the S2 waste-gate. I'm using the AGP waste-gate and i boost 18psi falling to 15 at red line. I'm also stage 1 but with vacuum line mod. more about the mod here. SRT-4 mod Q's newb to srt's here

Question on the AGP wastegate, how hard was it to get it set to the 18 psi spike and 15psi redline? I may pick one up, do you have to remove it each time you adjust it like the stage II?

[oklamopar]

just took some trial and error.
it the upper shield is off [like mine] all you need is a small crescent wrench.

just loosen the jam nut and turn the shaft. tighter to increase and loose to decrease.

[neverdone]

Quote:

Originally Posted by oklamopar just took some trial and error. it the upper shield is off [like mine] all you need is a small crescent wrench. just loosen the jam nut and turn the shaft. tighter to increase and loose to decrease.

Thanks for the info. I was reading some issues with the AGP being part throttle boost are you having any issues with your setup?

[oklamopar]

I had to learn how to drive it but once you learn it i can control it when driving "normal" it will boost high under half throttle if your not careful but i drive light throttle normally anyway , but if i want to boost i just floor it. if you don't want to have to watch your pressure and you drive heavy footed i recommend staying stock and just go with staged up grades. my next stop is stage3r with toys. no thinking on the tuning and ive seen numbers of 350 to 380 just plug and play.

[neverdone]

Good advice I will prob just bite the bullet and go the full Stage II upgrade, I like plug & play.

[oklamopar]

go ahead and get the toys. not much of a hp gain but well worth the extra $$$$$.

[njshift]

Quote:

Originally Posted by oklamopar go ahead and get the toys. not much of a hp gain but well worth the extra $$$$$.

+1. The toys does not equal a huge gain in peak horsepower but it did make very noticable increases in power throughout the rpm range. Now with all the great water/meth injection kits HOM is available at the flip of a switch without having to add 100 octane gas.

[t3rse]

The turbo is small and cannot support more than 15# in upper rpms. The reason you feel better drivability with sII is because it does the same thing, allows spiking.