Oh, in that case get the headers FOR SURE! You will HATE yourself if you don't get them now and then have to install them while the engine is in the truck.

 

Good, so what brand provides better power, regardless of price. i am hearing Doug thorley so far, what about TRD and downey?

 

I have never seen real verifyable dynos for either of those brands. This is why i went with Doug thorly, they proved that their headers made a differnce. Plus looking at the design, they really are quite nice. The only change i would have made is a 3" collector instead of 2.5. But they did the 2.5 to make it easy to connect to the stock exahust system.

Otherwise the design is about as good as you can get, plus they also fit.

TRD is way overpriced IMO, i have never been a fan of TRD proudcts except the superchargers.

 

You've got it backwards, all these "free flowing" mods make the power peaky @ high RPMs. There is no scientific basis for a header to make more power at 1500-2500. Stock headers and exhaust flow perfectly well at those RPMs.

 

Reason or not, the dyno says that it gets power from idle on up.

 

Ok, so where is the cheapest place to buy top of the line Doug Throley headers? I want to compare them with Downey. i dont think i will use TRD because of the price.

 

I got mine from www.URDusa.com. That was the cheapest i found but you might be able to find it cheaper.

 

Let's see the dyno plots for the Thorley headers on some NA trucks!

I'm semi interested in these. A nice gain of 10-15hp would be pretty nice IMO, and would really improve the day to day driving characteristics of these engines.

 

The dyno i am talking about was on an NA truck, i know they did one on a supercharged truck as well but i don't remember if i saw that dyno.

I just wish i had saved the dyno i did see.

 

They ran it on my truck when it was NA search here in the group buy thread and you should find it. It is also on CT. If i grab my laptop out of the 4-runner i will post it

 

For every dyno graph you find that show a noticeable gain at 1500-2500 RPM from those high flows mods, I'll find you a graph of fuel line magnets that increase MPG by 30%.

 

https://www.yotatech.com/50621481-post109.html

 

http://www.customtacos.com/forum/sho...06&postcount=1

 

this is from my truck in the week following, the ecu learned and picked up a few more. I would love to re-test it but, i have added a sc

 

MPG is not testable like a dyno.....

Read the dyno below, i now have it saved so i can post it when this comes up next time.

Plus with tuned headers you will get gains thoughout, these were not designed to be tuned that i know of but it looks like they lucked out and hit at least part of the tuning sweet spot. Which is why it has gains from idle on up.

You are correct that extra flow alone doesn't help much down low, but tuned header on the other hand can help a lot.

 

Now here is my problem...Doug Thorley Headers have the crossover pipe which you all know causes problems with the swap into 2nd gens. Where as Downey Headers permit me to run two pipes separate from each other and no crossover needed. So is it worth the hassle to get Doug Thorley Headers?

 

Well in this case i have no idea, i just know that in a 3rd gen these work perfect.

If you are putting it in a 2nd gen you might want to go with another brand.

 

Yea, i am looking at BBK for some prototype or I'll have to buy Downey.

 

If I did the swap over again this is what I would use and its made by ORS I think its around 350$ however they are going out of business in a few days.

 

Where is it? I need a good laugh.

The 3.4 makes what about 30-40hp at 1500rpm? And you say it gained 10-15hp through the band?