low numbers after h/c
Joined: Nov 2001
Posts: 3,043
Likes: 0
From: Texas and Qatar
IMO I think you should ditch the cats and retune at least the air/fuel without the cats to get a correct A/F ratio. If that wideband was reading after the cats it will skew the A/F ratio that the dyno reads (will look smoothed out and leaner), so your actual A/F ratio might be a lot richer at the engine than you think.
Some cutouts or QTP electric cutouts before the mufflers would probably be worth 8 or 9 rwhp. With both the !cat mod and cutouts you'll be where it should. Not sure what induction setup you have, but a porting the TB (if stock) will help find those last few HP as well.
One of the sales guys asked me about your setup the other day and while the HP is not that low, the tq jumped out as being low, at the time I didn't know your whole setup though, but yea try those things and I'm sure you'll be happy with the final outcome.
Some cutouts or QTP electric cutouts before the mufflers would probably be worth 8 or 9 rwhp. With both the !cat mod and cutouts you'll be where it should. Not sure what induction setup you have, but a porting the TB (if stock) will help find those last few HP as well.
One of the sales guys asked me about your setup the other day and while the HP is not that low, the tq jumped out as being low, at the time I didn't know your whole setup though, but yea try those things and I'm sure you'll be happy with the final outcome.
I did have the TB ported and polished. After tuning and driving for a few days, the rear of the car was all black and the smell of fuel is still present. You are right about the cats.
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
yeah, the numbers are a bit low, could be various things:
1- Tune
2- Try at another dyno but without lid/filter, then another run with lid/filter, if big variation your motor is starving for air.
3- From my experience with that cam, getting higher compression/quench and DCR wakes up the trq potential. The trqr cams I think are misslabeled.
4- I gained 12 rwhp by removing cats
1- Tune
2- Try at another dyno but without lid/filter, then another run with lid/filter, if big variation your motor is starving for air.
3- From my experience with that cam, getting higher compression/quench and DCR wakes up the trq potential. The trqr cams I think are misslabeled.
4- I gained 12 rwhp by removing cats
TECH Apprentice
Joined: Oct 2006
Posts: 362
Likes: 0
From: lubbock, tx
i think you need to get retuned on a dif. dyno... maybe even mil the heads just a lil.... tsp had one a while back w/ the setup i'm going with (look at my sig.) putin 480rwhp... lose the cats and get more flow and it will help
I just dyno on a different dynojet to make a comparison today. Got 422hp/362tq. An increase of 10hp and same tq numbers. I plan on removing the cats. How much of an increase if I decide to mill the heads (by how much)?