Doug Thorley Tri-Y Headers

[Tim Garceau]

Getting ready to order soon, probably going to add in an electric cutout and *4” C/C if it fits before the main hanger.

Have you had to tighten bolts or add any heat protection around the 8 speed/wiring components? Coating holding up?

Thanks!

 

[2010 Infantry Vet]

Looks like a far better design than overpriced ARH. 14 gauge and the ceramic coating will be fine even In the salt belt. If it rusts, it will just be surface rust which you can t see the headers anyway, so who cares. I know will be following this.

 

[clint440]

Getting ready to order soon, probably going to add in an electric cutout and 3.5” cat if it fits before the main hanger.

Have you had to tighten bolts or add any heat protection around the 8 speed/wiring components? Coating holding up?

Thanks!

Coating still looks new on the headers, and have not needed any additional heat protection. Headers are very compact so there is good clearance between components. I did have to re-tighten the O2 sensors but that probably has more to do with me not having a big enough line wrench or a selection of short stubby wrenches in the first place. Using a crescent wrench can be a little clunky. Header flange bolts all appear to be tight and I'm sure remflex gaskets help.

The two piece Y-pipe bolts onto the headers fine but did have some leaking on the middle connection of the Y pipe and where it slips into the main pipe. I ended up using the another u-bolt clamp on the main pipe in addition to the factory u bolt so it seems to finally have sealed. Also ended up using the the 2.5 U-bolt in the kit to get a better connection but still had a small leak. Messed with orientating it a different direction and actually twisted the bolt off. Ended up buying this which seems to have finally sealed the middle of the Y pipe:

https://www.amazon.com/Dynomax-3643...Clamp+Band&qid=1579575511&s=automotive&sr=1-3

Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube

I'm using the solo mach 44 as a muffler by itself but have noticed that the truck sounds off in cold weather so I think I will add a CAT. Don't know if the muffler is breaking in or if drone is just more present during cold weather. I have to do some research on what type of CAT to add. It seems CATs have to be sized for the size of the engine so as not to plug and do you get ceramic or metallic, 200 cell, 400 cell? Does the tuner account for a single CAT after the O2 ports?

Overall, I still think these headers are great in terms of quality and value. In addition they have some great attributes that even the expensive 4/1 set-ups just don't have.

The Y-pipe could use some refinement. The good thing about the Y-pipe is that it is 14 gauge, the bad thing about the Y-pipe is that it is 14 gauge so it's hard get a good mechanical connection with the hardware they give you. Either look at welding it which could affect the coating or upgrade clamps and use some type of sealant.


Performance wise, the pickup just gets to speed with much less effort, less downshifts, passing is effortless with unintentional acceleration to 90+. Mileage seems a little improved. I'll eventually get some 0 to 60 times to compare.

Mileage wise, I remember getting 16.5 bone stock on the interstate at 75, now it's 18.5 going 77 to 80ish. I'd say a good tune is worth an MPG and headers probably add another mpg.

I'm running an unoptimized Jay Greene tune, meaning I haven't sent any logs yet as I may add a CAT. So who knows, there might be more gains to be had.

 

[Tim Garceau]

Yeah, definitely send Jay logs and communicate where improvements can be made. He’ll get it dialed in based on the truck primary o2 sensors as I presume the base tune should be on the rich side open loop to prevent timing retard from the knock sensors. In cold, low elevation regions the dense air will lean out the mixture along with winter gas blends.

The converters are all personal preference with smell, sound, restriction, material variables. At the 400whp level, they aren’t hurting top-end performance significantly IMO.(if sized to not restrict flow)

-Tim

 

[clint440]

Looks like a far better design than overpriced ARH. 14 gauge and the ceramic coating will be fine even In the salt belt. If it rusts, it will just be surface rust which you can t see the headers anyway, so who cares. I know will be following this.

That's what I was thinking.

I'd say the main drawback is there no option of a Y-pipe with CATs built in. I'm not familiar enough with other brand's quality of Y pipe and how it bolts in, but having a custom built Y pipe with two high flow CATs built in, puts it into ARH territory as I'm finding out.

 

[Tim Garceau]

Just ordered, but to be clear did the long lap/butt joint clamp have leaks? I see there is one under your trans pan.

 

[clint440]

Just ordered, but to be clear did the long lap/butt joint clamp have leaks? I see there is one under your trans pan.

Yes it leaked, it's a cheapy from O'Reillys so disregard that picture.

Use the U bolt in the kit or use what I recommended above in the amazon links.

The U bolt with the sealant could probably work, but by itself it had a small leak.

 

[Tim Garceau]

You're not the only one who has had this occur with provided hardware. I communicated this politely so we'll see what they suggest. If I need to weld or purchase additional hardware it was worth the email so at least they're aware.

 

[clint440]

You're not the only one who has had this occur with provided hardware. I communicated this politely so we'll see what they suggest. If I need to weld or purchase additional hardware it was worth the email so at least they're aware.

They also didn't provide the right bolts for the Y pipe to header flange connection so either reuse the OE bolts or upgrade like I did. DT is trying to get in the MOPAR market as the sales guy told me, there still refining their product, I do recall him saying that he advised the parts people of upgrading the clamps so hopefully with more real world customer feedback they will further refine their product.

 

[clint440]

UPDATE

Finally had a dry day to really get rough performance numbers but my 0 to 60s definitely improved. Clocking it myself so not precise but you get the idea on increases: I had a 5.14, 5.55, and a 5.7 with DT Headers, Jay Green 91, no CATS. The best I had before was 6.00 with Jay Greene 91 tune with manifolds.

You really have to ease into the throttle otherwise it just obliterates the tires and you get like 8 second 0 to 60s as there is no traction.

I'm not a racer so have no official 1/4 mile slips but seat of the pants and my new numbers indicate these DT Headers are an upgrade.

 

[clint440]

UPDATE

Did some towing a couple weeks ago with a 24ft enclosed car trailer(about 30ft in length with the v-neck and tongue) probably about 4,000lbs in weight as trailer was mostly empty but a whole lot of wind drag. I haven't towed since it was stock but WOW, what a big difference.

The pickup would tow in the flats in 7th gear at 65ish and even accelerate slowly without having to downshift and 6th gear (direct drive) gave you broad rpm range to speed up in bigger increments. When it was stock the engine could only use 5th and 6th in the at highway speeds, now it can comfortably use 6th and 7th and probably sneak into 8th at the right conditions.

Now this was with the regular JG 91 tune, I do have a 91 tow tune but didn't bother to download it for a short trip. The MPG lie meter indicated 10mpg, so probably 9mpg in reality. These headers really do add some oomph under 3,000rpm. Never thought a gas engine could confidently pull like a diesel.

Goes to show that headers and a tune have utility outside the dragstrip.

 

[DonnyP]

You're not the only one who has had this occur with provided hardware. I communicated this politely so we'll see what they suggest. If I need to weld or purchase additional hardware it was worth the email so at least they're aware.

They also didn't provide the right bolts for the Y pipe to header flange connection so either reuse the OE bolts or upgrade like I did. DT is trying to get in the MOPAR market as the sales guy told me, there still refining their product, I do recall him saying that he advised the parts people of upgrading the clamps so hopefully with more real world customer feedback they will further refine their product.

Any updates on these issues? Tim, did you ever hear back from them. Was the bolt and clamp problem resolved?

I live in WI, so a pretty bad snowbelt area and I'm looking into getting these headers to fix my broken manifold bolt issue.

I found a set of these, with catless Y pipe for a pretty decent deal.

 

[clint440]

Any updates on these issues? Tim, did you ever hear back from them. Was the bolt and clamp problem resolved?

I live in WI, so a pretty bad snowbelt area and I'm looking into getting these headers to fix my broken manifold bolt issue.

I found a set of these, with catless Y pipe for a pretty decent deal.

I just got bolts from ACE hardware and upgraded to a band clamps and used a little of the exhaust Permatex. No leaks to this day.

You could just check with the Vendor and see if they got more refined in hardware, I was one of the first ones or so. Considering what you get for your money under a grand, features and fit that 2 grand headers don't have, I'd still use DT again.