Downey Headers- Test Results

[tickin'tundra]

Boys and Girls,

I just installed a set of downey headers on my Tundra this weekend. After 150 miles of driving, I went out and ran her to see what difference it made. The truck feels more responsive in all situations now. But the real test is below.

As Measured with G-Tech -

Before:

0-60 7.34 sec.
1/4 mile 15.67 @ 91.70

After:

0-60 7.18 sec.
1/4 mile 15.52 @ 91.84

My truck is otherwise stock with the exception of a flowmaster dual inlet and single 2 1/2" outlet muffler.
Well worth the $400 I paid and the 8 hours of knuckle bustin' I spent installing these things. The stock exhaust manifolds belong on a sears lawn tractor. They measure only 1 3/4" O.D.!

[v8Toilet]

I assume you have a dual inlet and single outlet muffler so that you could eliminate your stock y-pipe, great idea! For your truck to go 0-60 in less than 7.5 seconds is really amazing! A stock Tundra will go 0-60 in 8 seconds on a good day.

So were the Downey headers a direct bolt on or did you have to cut and weld? What size primaries do you have? Did you lose low-end torque?

Thanks in advance.

[tickin'tundra]

Originally posted by v8Toilet
I assume you have a dual inlet and single outlet muffler so that you could eliminate your stock y-pipe, great idea! For your truck to go 0-60 in less than 7.5 seconds is really amazing! A stock Tundra will go 0-60 in 8 seconds on a good day.

So were the Downey headers a direct bolt on or did you have to cut and weld? What size primaries do you have? Did you lose low-end torque?

Thanks in advance.

Yes, I got rid of the stock Y pipe and ran 2 1/4" dual inlets from the cats to the muffler, and a single 2 1/2" tail pipe to replace the stock 2 1/4" pipe.. I actually used a FORD tailpipe and it looks great.

The downey headers are a quality product. However, the stock exhast pipe must be cut in order to install. I have a sawsall tool so it was no big deal. If you are cutting with a hacksaw you had better eat your wheaties. I don't know what the primary size is, but I'd guess 1 5/8". No loss in low end torque at all. In fact, I noticed that I can lay a ton of rubber around a corner now and before it was not quite so dramatic.

The 0-60 numbers are from the same G-tech on the same stretch of road at basically the same temperature. So I'm confident of the results. I've seen a wide variety of 0-60 numbers in magazines and in this forum, so I guess there are variences. But the bottom line is there is a difference when installing these headers on a Tundra!

[v8Toilet]

Sounds to me like the Downey headers are comparable to the TRD headers for less than half the price.

Using my Drag program I figured you gained 25 horsepower and 35-lb. ft. of torque at the crankshaft to get a 15.5 @ 91 mph in the quarter mile. That is a 10% horsepower increase and an 11% torque increase or 270 horsepower and 350-ft. lbs. of torque. I did this using a 2WD Tundra weighing in at 4250-lbs. and 4430-lbs. including a driver.

If you had 20% driveline loss than you would have 216 horsepower and 280-ft. lbs. of torque at the rear wheels.

Very nice!

[AKTNDR]

How do those compare to the JBA headers?

[tickin'tundra]

I have personally not seen the JBA headers. But I believe the JBA's are a "shorty" style header that bolts on to exisiting exhaust system requiring no cutting or welding. They are also more expensive...

[1badtrd]

I just finished installing the JBA Headers ($350 from ebay with shipping) yesterday and I am quite impressed. The install was a little tough (5 hours driver’s side and 1 hour passenger side… once I figured it out). There was no cutting or welding required.
This morning was the first chance I’ve had to test them out and there is a noticeable increase in power. I am going to get a G-Tech this week and see where she’s at.
I will try and get some pictures of the installed headers up this afternoon since I’ll be in there putting in the lift anyway.

[v8Toilet]

What kind of results did you get with that G-Tech?