Jason 98 TA

iTrader: (4)

After 5 days of engine dyno testing different combinations & packages I'm proud to announce I finally have some extra time to provide you guys with some of the information we've learned!


The very first dyno testing we did compared header primaries & power output from 3000 to 6000rpm. The base engine was completely stock 01 engine with only a Fast intake installed. We dyno tested both the Pacesetter 1 3/4" coated long tubes & the TSP 1 7/8" long tube headers. The goal was to see how the larger primaries would effect power on a basically stock engine. To my suprise the 1 7/8" headers made a considerable amount more power than the 1 3/4" headers! Power output was virtually identical untiL 4800 rpm when the 1 7/8" headers began to outpower the smaller 1 3/4" primaries. The 1 7/8" headers made a peak hp of 414.x hp & 421lb ft while the 1 3/4" headers made 408hp & 419 lb ft of torque. While this isn't a huge difference, it definately shows that even on a basically stock car the larger headers are still a good investment! Power under the 4800rpm point was virtually identical! Infact the 3000 rpm numbers were 209hp 366 tq from the 1 3/4" headers & 209hp 359.9 tq!

Both dyno runs were backed up several times & the combos used very similar air fuels & locked in timing at 28 degrees. I thought this was a pretty cool comparision, because the common thought is the 1 7/8" headers is just overkill on anything smaller than stroker setups. This is apparently not the case....

Here's a few pics of the 1 7/8" headers installed on the engine dyno



The dyno video can be seen at:

http://www.precisionracecomponents.com/178dyno.mpg

I'll have some of the guys help me bust out some detailed dyno graphs for you guys to checkout in the morning.

Enjoy!!

I would like to offer anyone who doesn't agree with these finding to come down to our shop & I will be more than happy to redo any testing we've done over the last 5 days. All our engine dyno testing was done at a independent dyno facility & as long as your willing to pay the dyno testing fees, I'll glady reproduce any testing we've done. This is a very reasonable offer, if you don't want to put your money where your mouth is then please don't jump in this thread & talk crap. I'll gladly defend any testing we've done, I'm always looking for a opportunity to get back to the engine dyno for more testing.

DrkPhx

iTrader: (15)

Good results. It would be nice to that test on a stroker spun up to 7000 rpms to compare the results.

NMJ87T2

iTrader: (26)

From your picture i see that you are running truck coils. Is this something that you recomend?

I am torn about weather to run 1-3/4 or 1-7/8 headers. Do you have any tests from idle to 6k? To see if the bottom end suffers from the larger primaries.

Thanks
Nolan

DrkPhx

iTrader: (15)

He said it was identical under 4800 rpms, which sounds like no loss of power down low.

NMJ87T2

iTrader: (26)

Yes, I saw that , but he also said that the test was from 3k to 6k. I am not going to assume that this includes from idle. I am a stickler for detais.

Nolan

Summerwolf

iTrader: (3)

what rpms do you race at? Idle....When you race are you above 3k? Yes....sounds like a win/win from almost any standpoint.

PowerTalk

This is just what a well known Australian workshop has been recommending for years!
1 7/8"s make more power on everything from stock LS1 engines and right through to massive H/C combos

So now here's more proof

Jason 98 TA

iTrader: (4)

Sorry guys you just can't put load on the enigne dyno much bellow 3000 rpm. The engine dyno operator tried to talk me out of going 3000rpm!

JayplaySS

iTrader: (15)

1 7/8's - dumdumdum as Ive always said. Thanks TSP!

Now test them on a larger cube LS2/LS3/LS7 and they will shine even more.

ShoddyHog

iTrader: (1)

Yeah, but you'll loose so much "power under the curve", when you put it in drive, you'll strart rolling in reverse. lol

My LS2 seems to like my 1 7/8 Kooks.

Gerry

psrumors

iTrader: (2)

Not disputing the facts and very good test but couldn't collector design differences make up the 6 hp and 3ftlb?

Why not use a set of Kooks or other manufacturer that has both sizes to make the comparison?

Sales2@Texas-speed

iTrader: (5)

We wanted to test the two most popular headers WE sell to give actual data to OUR customers. But, we also tested Kooks 1 7/8" stepped headers as well.

psrumors

iTrader: (2)

makes perfect sense and very good test none the less.

It is great to see sellers go the extra mile to inform their customers.

Beach Goatxz

Good test, thanks.

tektrans

iTrader: (23)

When I had my old 408 I went from 1 3/4 to 1 7/8 and gained zero.
Zero on the dyno and Zero at the track. FWIW

racer7088

Jason, I have seen many many tests almost identical and we always see the 1 7/8ths make better power too. On the bigger stuff of course it's even a slightly larger gain.

ringram

Open headers? Or did you have an exhaust system behind them? Did you retune fueling/spark to take advantage of the extra airflow?

JoeyD

iTrader: (20)

That's good. Can't wait to bolt my ARH 1 7/8th set to my new set up.

99ssleeper

iTrader: (98)

Good info, thank you!

But I still want to see a dyno test from idle...hahaha

tektrans

iTrader: (23)

I had an x pipe and true duals dumped before the axle.
Was checked on the dyno, no changes had to be made.
All set ups are different, like I said-FWIW.