best mod? underdrive, throttle body, or high flow cats?

[mralbuquerque]

Which is going to give me the best bang for the buck mod between an underdrive pulley $249, throttle body $399 or high flow cats that the muffler shop can weld in?

I already have, 3.55 gears, sct tune, k+n filter.

Thanks!!

 

[plumcrazy]

TB will likely LOSE you power. the HF cats give you about 0 additional power. the underdrive pulleys about the same.

 

[Nader]

Throttle body you will not lose power but bang for the buck i would go with HF cats. Some extra power and great sound...

 

[cubican]

The tb and under drive dont do much, the best bang for the buck is the HF cats , but if I had to do it over I just gutout the rear cats.

 

[2easy]

I gut my cats. It took about 10 minutes or so per side, not including RandR. Louder, sounds good IMO and kept the cash in my pocket...well Im sure my wife spent it on something else. Those other mods you mention are a waste of time imo.

 

[agdetail]

ya taking off the cats will give 10-20hp more i herd. as long as you have a muffler on you should not get alot of droning or gas smells in the cabin.

 

[mralbuquerque]

Heres what i found on another forum:


Went to DC Performance today to test the new JTS Venom throttle body. Special thanks to Dan, Lyle and Chris at DC Performance, they even had donuts waiting. Most people know I had the BBK throttle body and like a lot of people it would fast idle on me , especially after some freeway driving. The JTS Venom throttle body did not stick once, even after the 100 mile drive home, perfect idle quality after pullling off the freeway. Crisp throttle response as well. We made 4 pulls with the BBK after arriving there and a cool down period. Baseline pulls were made at 10:33 am, temp 67.5 degrees and humidity was 8%. The pulls with the JTS Venom TB were at 1:18pm, temp 72 degrees and humidity was 18%, so the air wasn't quite as good as for the baseline pulls. All pulls were on a Dynajet dyno, so I was turning my stock wheels with 325-40-22 tires on the back. The JTS Venom showed gains throughout the entire rpm range, not one negative. Very pleased !!!!!!Here are the results:

RPM BBK HP JTSV HP Gain BBK TQ JTSV TQ Gain
2700 241.98 245.60 3.62 470.71 477.70 6.99
3000 267.72 270.23 2.51 468.69 473.10 4.41
3500 329.02 332.57 3.55 493.71 499.04 5.33
4000 394.11 397.01 2.90 517.46 521.26 3.80
4100 407.70 411.27 3.57 522.25 526.83 4.58
4500 445.98 450.74 4.76 519.94 526.08 6.14
5000 477.19 483.11 5.92 501.25 507.49 6.24
5400 489.71 496.26 6.55 476.32 482.68 6.36
5500 487.13 494.59 7.46 465.20 472.32 7.12
5600 486.21 493.27 7.06 456.03 462.65 6.22
6000 480.26 486.25 5.99 420.41 425.65 5.24


All results SAE corrected.
Peak torque reached at 4100 through 4500
Peak horsepower reached at 5400, held good through 6000
Uncorrected numbers were 509.53 RWHP @ 5400, 540.92 RWTQ @ 4100

 

[MTGTS]

I would dump the cats unless your state has inspections

 

[STUGOTS]

Phil is right, the TB actually made me lose power until I did a few more mods, on a stocker its not worth it, now add some power and need some more air different story.

as far as power gain I'd say underdrive but I've never been a fan of them, due to the possible side effects. so I'd vote no on that one as well.

so overall I'd say cats, at the very least cutting down 4 cats to 2 will save heat and scorched legs lol