DD exhaust w/LT headers w/sound clip pg 8 post 229

I can imagine. When I had my ECU programmed through that Overland tuning it got me hooked. My truck went from feeling like you have to push it to where it felt like it was begging you too accelerate

 

Nice!

I got hooked on it in the early 80s but had to give it up. I rebuilt the engine in my Mustang cobra with a very high-performance cam, bigger valves, and some other mods and was so fast that the rest of the car was not built to handle that much power and torque.

Then I bought a 66 Mustang fastback and had big dreams for it, but just couldn't afford to To do all I wanted to do since I was going to school at the time

but the one thing I never got that I wanted so bad was headers

 

I always told myself if I ever owned a V8 I'd buy headers and I kept my word. Having gone from a 4banger ranger to three 5vz v6's, now two 2uz v8's.
These may not be the fastest v8's, but I don't know any better and I'm having a ball in both my trucks!

 

I just now noticed you said the dyno results were from non-VVTI engines. Maybe I'm presuming too much but I would think it could potentially be a little more with VVTI engines if you get the tune

 

Definitely.

 

I don't have the DD/JBA 4-1 long tubes, I have Stan's 4-2-1 tri-Y. I gained about 40ft-lbs at the low end. My VF Tuner arrives Monday 6/10 and I'll dyno their 93 octane base tune. I'll do a thread and dyno pulls with the tune in a few weeks.

Doing a re-gear to 4.30:1 and some Kelford cams later this year or next year.

'06 VVTI.
Blue line DD 12 hole injectors, everything else stock

Red line Tri-Y headers, full 2.5" single exhaust, AEM dry flow drop in filter.

 

I admit the 1-5/8" primaries of the tri-Y are a restriction and the DD/JBA long tubes are 1-3/4". You'll get better top end power than my numbers.

I've emphasized maximizing low end power with my tune. I may swap to DD headers and single 3" exhaust when I go supercharged. My current setup will be a major bottle neck under boost.

 

Impressive gains for sure, looks like it smoothed out the vvri/intake runner changeover as well. Bet, she can do a good burnout. Sounds really good too! Never seen this info before today.

 

It brings a lot of oomph to where the truck is normally driven. Since it's an automatic it spends most of its life below 4,000RPM. You can see from my dyno there's no point in ringing my truck out to redline, except to hear the Borla scream.

Dynos have proven time and time again that 4-1 long tubes and larger diameter primary tubes typically yield a lot more top end, and in some cases better bottom end, compared to the tri-Y style.

My parts decision was based on typical driving habits and improving low end torque. I guesstimated that the chosen smaller primary tube, and collector type on a stock flowing head and stock displacement would work for what I wanted. My dyno showed a big improvement right where I wanted it.

This doesn't mean that the DD/JBA will sacrifice tons of bottom end torque it in favor of top end horse power. At the time of my purchase I didn't have a dyno graph of the DD/JBA on a VVTI motor to compare it to.

Given a true apples to apples comparison I'm sure if there were any power trade-off of the DD vs tri-Y it would be well worth the difference in low end vs top end. At any rate either header design will out-perform the OEM cast manifold by miles.

At any rate, Keith with DD wouldn't support a product for our vehicles if it weren't worthwhile. I spoke with him quite a bit before ultimately purchasing from another supplier. Nothing against Keith or DD, I had a ticking clock. Stan was retiring and he was the only one offering tri-Y style headers for our engine at the time. I ordered the last set of Stan's headers before he retired.

Bottom line is, many many members of this forum and others have purchased headers and exhaust systems from DD. And many more continue to do so. They all have been satisfied with their purchase and power. Keith chose to back the 4-1 style, and he certainly had his reasons.

 

Well said, the different designs have their advantages. Your set up is nice, and thank you again for sharing your results. Hige help to all of us.

I know my trans will be different but did you make that pull in 3rd gear? Ive never had to run a auto on the rollers. And are you running some type of ecu tune? Any info on that would be great to hear about.

 

Truth be told I didn't pay attention if he did the pull in 3rd or D with O/D off. He did run the truck up over 90MPH on the dyno so I suspect it was with O/D off.

Both runs were with stock ECM and Dirty Deeds 12 hole injectors. My tuner is supposed to arrive this afternoon and I'll be back on the dyno in another couple weeks.

 

I took a peek from directly under the engine, and now I can see what they mean by disconnecting the engine blocks, loosening the dipstick, and a few other things that have to be pushed out of the way. Doesn't look quite as daunting as I was anticipating after hearing what I was involved, but still time consuming


I'm gonna hit the nuts that I can see with PB blaster today. It looks like I can't get the most of them until the heat shield is removed.

Speaking of which, I don't see how these headers can work with the existing heat shield. Is there a replacement for it?

looks like the headers and exhaust were shipped Friday and will be arriving late this week. So I should be able to get started next week.

 

You’ll also need to loosen the AC compressor, oe heat shields get thrown in the trash. Lift the engine by the oil pan with a block of wood(careful for the drain bolt) and remove one side, install header, replace engine mount and then do the other side

 

That's what I thought re: heat shields. I guess I might as well see if I can remove them so I can get to all of the exhaust manifold nuts

Looking from underneath it's hard for me to imagine the headers fitting in there at all


You said OE heat shields - are there some different ones available for the headers?

 

It’s definitely tight like a tiger

 

How does it even accommodate DD's dual exhaust with his headers? I don't see room on the driver side. And it certainly can't get by the gas tank on driver's side

 

Don’t bother with heat shields. Some people have wrapped their headers but it’s kinda frowned upon especially if you live where it’s wet and salty.
Unless your getting race exhaust, it all merges over to the passenger side, similarly following the stock routing.
You also want to make sure your shift cable doesn’t come/stay in contact with the headers

 

It is his dual exhaust system. I believe he called it the racing system. I'm going with a much quieter muffler combo


EDIT: After reading over our texts, i'm embarrassed to say I'm confused over what I ended up with. But that's because most of the conversation was over the phone.

it is confusing with it being a small shop because you don't get an invoice by email to confirm or have any specifications to go by and we discussed many different options

 

The x pipe is where the equal length comes in on the race exhaust.
It crosses by the carrier bearing over to the passenger side. It's kinda hard to explain. But you'll see what I mean once you get it.
It's a pretty cool design, but it does leave some low hanging fruit, which is a concern for rock crawling. But so far I haven't hit mine on any rocks.

 

Mine is 2WD and not used for off-roading or rock crawling although I have no doubt that is a blast and I would be hooked the first time I did it

so that's not an issue for me, but it does help me understand.



I will see in a few days

 

Yes, I noticed that shift cable this afternoon. One of several reasons I just can't imagine how this system fits under there

 

Use those old heat shields to protect you shift cables. Slight modification to heatshirld required lol.


You will get them on and dialed in. Im sure ill be hi temp gasket'ing ( i know....) all types of shstuff. But i would assume everything but boot can withstand the heat. I would just watch and inspect frequently for clearancing first few months. Keith prob has a solution for this. He gave me all types of tips for smooth install but it was like 1am eastern time and i was mainly interested in his turbo tundra.

 

Either way I will def keep my promise to document since there seems to really only be one install vid that I know of.

 

Good tip about modifying that heat shield.

yeah, he's very busy and I hate to bother him with a lot of install questions. But I don't see any documentation or videos on his website. I would also really like to see more details and specs. I trust it's a great system, but we're also paying a price for it

And I trust that he has optimized this exhaust, but I still like to have the details of what I am buying documented. Right now, it was discussed on the phone one time but with all the different options we spoke of it's a little confusing and there's many questions I never asked

 

Yes, I see what you mean. I can't wait

 

I'm excited for you, bud.

 

I feel like his equal length looks a little different than yours?

 

I don't think so. If it weren't raining here, I'd go look haha

 

@455h0le_dachshund

got pics?

 

I think it was you that mentioned how low they hang. I see what you mean now!

That hanger is very tall