I bought the 03 in my sig about a month ago it is basically stock except for the air filter system and exhaust. It seems low on power when towing compared to my 95, also in sig. The 03 runs great empty, gets about 20mpg, and seems to have plenty of power. The low power is only noticeable while towing our 5th wheel up grades at 60mph +. I am seeing 5-10mph loss on my usual test hills with the 03 vs the 95. Boost is up around 28psi and EGT's are low at only 1000F max, even in 6th floored, and lugging down to 55mph. I am guessing a fuel problem? I changed the fuel filter but there was no change, also the lift pump is already in the tank. Am I on the right track, do I have a problem? Or does this sound normal when comparing a 160 hp slightly modified 12 valve to a stock CR? Thanks for the advice.

 

I would think it would pull a little harder than that. Floored close to peak power range (2500-2700) I would expect to see EGT's closer to 1200.

Is it the high output engine?

 

Thanks Jeff, yes it is the HO 305hp. I haven't had the rpms that high "2500-2700". I guess I am used to the 12 valve which I used to keep under 2200. Our speed limit is 65 and at that I am running about 2000 rpm. Maybe that is my problem, am I not giving it enough revs? Does the 03 build it's peak power at that rpm range?

 

yea they do, get them rpm s up

 

So if 2500-2700 is peak hp what is the max rpm for this engine? Would a Smarty help at lower rpms?

 

I don't think you should have to have the rpms that high. Max torque comes on @1600 and remains pretty much flat till redline. My wife's '03 isn't as powerful as my '01 but I don't expect it to be since the '01 is loaded with goodies. Her's pulls our TT just fine but will downshift on hills but that is expected.

 

Do the Smarty.A stock crd power output comes on very smooth,unlike a 12v where you can tune it to hit hard where you want it.The smarty will wake up the bottom end

 

yeah i agree with bob on this.. The 305hp has a pretty smooth torque curve to it unlike the 12v torque curve (which is pretty snappy imo). Get that smarty and set it up to how you want your power to come alive at..

 

Thanks guys. I had never driven a 3rd gen prior to buying this 03. I miss the low end torque of the 12 valve but sure like the truck. I am glad to hear the Smarty will help. Should I also look into a boost fooler or anything else at this time? I don't need big HP just enough to pull the 5er at the speed limit.

 

If you are seeing 28psi then someone has already worked on your turbo, and you probably have a boost fooler.. If you don't have a boost fooler then you could be defueling, without a code... 1000* does seem very low.

Take a pic of the turbo and of the elbow where the WG gets its air.

 

yeah id say your right, because i believe that stock pressure is around 22-24psi correct? although my old 555highoutput never ran hot either, id have to really work it to see high numbers with it being set at stock levels of course...

 

2700 RPM is where the HO makes peak HP. Torque is pretty much flat from 16oo to 2700.

Mine would only show higher EGT's when spun up a bit.

Anyway, try grabbing 5th when you are pulling a load up the grade.

 

Should be in the 22-24 range.

305 hp @ 2900rpms
555 ft/lbs @ 1400 rpms.

Tq curve is very flat from 1400-2900.




What gears/trans did your 95 have?

 

Here are the pics. No codes when I bought the truck, I will pull them again to be sure.

 

3.55 gears and 47rh auto