Stock Motor 1 3/4" Vs. 1 7/8 Engine Dyno Results!!
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.
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Last edited by Jason 98 TA; Sep 4, 2008 at 08:56 PM.



They are both 1 3/4" headers, and I can guaran-damn-tee you that the Edelbrock 1 3/4" headers will outperform the Pacesetter 1 3/4" headers just the same.
IMO, this comparison is meaningless because you're comparing a quality header to old, bottom-of-the-barrel junk. You need to compare the same design. If it were Kooks 1 3/4" headers vs. Kooks 1 7/8" headers, then I'd be content. if it were ARH 1 3/4" headers vs. ARH 1 7/8" headers, then I'd be content. That way, it's an apples to apples comparison.
Also, the fact that you can't show power below 3000 rpms is discouraging. That is the powerband for daily driving, and that's where the 1 3/4" headers shine. You're not going to see the benefits of the 1 3/4" headers because the dyno won't allow it.
I'm not trying to insult you or discourage you. I'm just pointing out facts. It's a bad comparison by not choosing the same brand and design, and even if it were, the dyno leaves out the very powerband that shines with the smaller primaries. I'm not going to sacrifice a 15rwtq loss @ 2200 rpms for a 3rwhp gain at 5800 rpm's. Sorry to be a buzzkill.
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great comparision test. Wish i would have known this a few years though. You guys do great work down there, most of whats in my sig came from TSP and i couldn't be happier. keep up the good work. The Best V8 Stories One Small Block at Time
Honestly, I'm not trying to be disrespectful at all to Jason. I'm 100% confident that if his headers were 1 3/4", they'd still outperform Pacesetters just as well if not more all over the curve. His headers are just a better design. Pacesetters are garbage by comparison of almost every other newer header on the market. I've seen QTP's make 18rwhp and 30rwtq over Pacesetters on a H/C car in the midrange. That's 1 3/4" vs. 1 3/4" headers. Brands make a HUGE difference. We need the same brand, same design, different primary diameter on a stock motor, all tuned to the ideal AFR. Only then will this argument be laid to rest.
On the upside, I'm happy to see a bone stock motor with just an intake and headers make well over 400 hp. Glad to know I'm past that
Also, the fact that you can't show power below 3000 rpms is discouraging. That is the powerband for daily driving, and that's where the 1 3/4" headers shine. You're not going to see the benefits of the 1 3/4" headers because the dyno won't allow it.
I'm not trying to insult you or discourage you. I'm just pointing out facts. It's a bad comparison by not choosing the same brand and design, and even if it were, the dyno leaves out the very powerband that shines with the smaller primaries. I'm not going to sacrifice a 15rwtq loss @ 2200 rpms for a 3rwhp gain at 5800 rpm's. Sorry to be a buzzkill.
Someday if we ever get a dyno on-site at TSP I'll spend a day testing headers. I can't test y-pipes or any exhaust though, the dyno is RIGHT where the exhaust would end up, it was a crapshoot whether F-body headers alone would even fit until we tried...
Edit, I'm not quite sure if we can run a loaded engine dyno below 3000rpm. I'll find out for next time though.
The eye dyno lies to people all the time. This was a very good comparision because it showed that even at stock motor levels the larger 1 7/8" primaries can produce a little bit more power. For headers that cost very comparable that is a great option for our customers. Honestly I don't care if the customer buys 1 7/8 or 1 3/4" headers as long as they buy from us! Our goal is to give our customers the most accurate data for making purchasing decisions.
I'm not trying to insult you or discourage you. I'm just pointing out facts. It's a bad comparison by not choosing the same brand and design, and even if it were, the dyno leaves out the very powerband that shines with the smaller primaries. I'm not going to sacrifice a 15rwtq loss @ 2200 rpms for a 3rwhp gain at 5800 rpm's. Sorry to be a buzzkill.
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com





