Doug Thorley Header on my 2.4

I finally broke down and bought the header I've been wanting for a long time. Doug Thorley is the only company that makes a header for the Taco 2.4. I expected some increase in performance, but nothing like what it turned out to be.

It's hard to put into words exactly, all I have is seat-of-the-pants feel to go by since I don't own a dyno. Low end torque is much improved, so much so that my eyes widened and I caught myself thinking "holy cow."

As I let out the clutch to a slow roll, I punched it to about half-throttle and thought the back tires were going to break loose. In reality, we know that a 2.4, naturally aspirated, won't break the tires loose. But that's what it felt like.

I've been less than stellar about cleaning my Volant air filter, so, after three years, I ordered a new one along with a Volant pre-filter. With a header and a new air filter, throughout the entire rpm range, the "operation-in-general" of the truck is smoother--at idle, at slow speeds, part-throttle, and at highway speeds, it's smoother.

So if you own a 2.4 or a 2.7, expect a vast increase in performance if you install a Doug Thorley header (I get no kick back from the Thorley organization for pitching their product.).

 

Any other mods? Where did you get it from? 2.4 will break tires loose.

 

I bought the header from neverenoughautoparts.com through eBay.
Volant CAI, DJM 3-4 drop kit with upper control arms and ball joint flip, Hurst shifter, knob and boot, LCE short throw shifter kit, throttle body spacer. I bought smoked head and tail lights only to discover they're illegal in Texas.

 

Do you know if these headers are commiefornia compliant ? any check engine codes ? Been thinking of doing this to my 04 2.4

 

Did you get long tube header?

 

From the looks of it , it looks like a shorty

 

Yea that's what I was guessing

 

It's legal in all 50 states. It is a shorty. As far as I know, it's the only header offered by any manufacturer for the 2000-2004 2.4 engine. Actually Thorley offers two headers for it: one with the chrome finish (the one I bought) and one without the chrome. No check engine codes. In my opinion, it's a superior product at a reasonable price.

 

Now that's a cool mod.

 

Got one in the box in the garage, can’t wait to get it installed now. Thanks for the positive report. Have been reading a lot (too much) and was concerned that there would be no gain in power.

 

Get an intake if you don't have 1 already. You'll really notice a gain with both

 

You’re reading my mind, that’s definitely next if not simultaneous. Been looking at the Injen, would you recommend that it any other?

 

I went with k&n with the plastic tube, no reason why I went with it over other brands I just found it on summutracing.com

 

I'm running Doug Thorley Tri Y Shorty header on my 3RZ 2.7 4cyl part ##THY - 511Y - 1 - C

It was recommended to me as it helps scavenge exh pulses quicker with no reversion and works well with my supercharger

 

The header I've got has a CARB EO# and 50 state legal

 

My 1989 4x4, 2.7L was a Dawg, .... I had to downshift out of 5th gear from 65 MPH to maintain 55 MPH at times on the interstate.

On a whim I disconnected the inside the fender snorkel to the air filter box.

This made the difference of one gear range, no matter what I was doing.
If ... I need 3rd to pull a certain hill before, I could now do it in 4th etc.

Then, I added a standard K&N air filter. This made another huge improvement.

Then, I connected the factory air box to the factory fenderwell opening for a "cold air" system with a discarded CVJ boot from the boneyard with some RTV.

Next, I switched to "Bosh , Platinum Plus 4", spark plugs, despite bad reviews I read; ... what a beast it became.

I could now run 5th gear on moderately level ground @ any speed over 40 mph.

Finally, I swapped out the factory muffler for a "Cherry Bomb" glass packed.

Later on I did the "Deck Plate Mod."

In the end anything above 50 mph was a 5th gear proposition. 75 mph was a piece of cake. Only on the steepest grades in PA (55 mph) highways did I rarely have to shift out of 5th.

On I-476 between I-76 (PA Turnpike) and I-80 I could pull a 50 mph @ 3200 rpm in 3rd gear while pulling a 3500# trailer and I was passing 18 wheelers that were pulling over out of the outside lane because they could no longer make the grade.

One of the very best things I did was to add a tachometer and a vacuum gauge. This helped me effickently monitor RPM and better predict/anticipate appropriate times to shift.

 

I know this is an old thread, but I am receiving my DT headers for my 2.4 later this week. Just glancing at the engine bay, it looks pretty straight-forward to install. Did you run into any difficulties? The instructions mention lifting the engine, but I was hoping to avoid that, because that would require more tools than I have

 

Easy install , rust and seized bolts is the main issue , get yourself ready by having extra star bolts that go on the head in case the old ones snap, https://youtu.be/kqNLNZctR1w best video for your needs

 

Thanks for the heads up. It's already soaked in WD-40, so I hope it goes smoothly. I bought it from the original owner 2 years ago with 25k miles. It was garaged the whole time, so hopefully, the rust isn't too much of an issue.

I was skimming through the video and noticed the header is cast iron. But the one on my 2.4L definitely isn't cast iron. It looks like the one that I attached

 

Yes pre 2001 used cast Iron , after 2001 they used the mini steel Toyota headers , my 04 had the one yours has stock , wd40 won’t do much pb blaster is much better ,