[ponjohn]

Originally Posted by Larry Navarro

I don't know if y'all are aware of my undertaking in production of Tri-Y's. I am in the process of having a jig built to produce headers and if the cost is sustainable, meaning I can make a buck or two from the effort, I will be offering "D" and "O" port configurations. I realize that most everyone would rather spend $300 on a cheap set of headers but there is NO way I could offer such a "bargain". It will be a while before I can get a cost analysis if my efforts are feasible but I wanted to give some "hope" that there will be another option in header choices. Do it once, do it right. "The bitterness of poor quality lingers long after the sweetness of low price is forgotten."

Hey Lee, I need to speak with you about fuel injection. PM you number please, thanks!

Larry what chassis are you offering these for?
And, what size tubes for D-port?

[steve25]

There is no doubt that with lower compression numbers and the lower cylinder pressure numbers that is made that you want as little back pressure as possible to impede the Exh gases/ pressure from getting out of the cylinder.

In light of this I agree with the statement that with motors under 9.2 to 1 you need a good flowing Exh system more and more as your compression sinks!

[West Coast GTO]

Well, if you are going to produce a tri y, will one be made for a 71GTO 455 with round port heads, P/S and A/C? I would be VERY interested!!!!!!

Originally Posted by Larry Navarro

I don't know if y'all are aware of my undertaking in production of Tri-Y's. I am in the process of having a jig built to produce headers and if the cost is sustainable, meaning I can make a buck or two from the effort, I will be offering "D" and "O" port configurations. I realize that most everyone would rather spend $300 on a cheap set of headers but there is NO way I could offer such a "bargain". It will be a while before I can get a cost analysis if my efforts are feasible but I wanted to give some "hope" that there will be another option in header choices. Do it once, do it right. "The bitterness of poor quality lingers long after the sweetness of low price is forgotten."

Hey Lee, I need to speak with you about fuel injection. PM you number please, thanks!

[MD79TA]

Great info on headers vs ram air manifold and good down pipes.
http://www.hotrod.com/articles/hppp-...-vs-manifolds/

[455GRIN]

Hey Lee, what cam are you using? I see the basic numbers but wanted to know which cam. I am putting together a low compression 455, I was going to use the Ram Air manifolds, now you have me thinking that, maybe I should use my Tri-Ys. Didn't realize low compression motor could take advantage of the headers.

[Lee]

Originally Posted by 455GRIN

Hey Lee, what cam are you using? I see the basic numbers but wanted to know which cam. I am putting together a low compression 455, I was going to use the Ram Air manifolds, now you have me thinking that, maybe I should use my Tri-Ys. Didn't realize low compression motor could take advantage of the headers.

I designed it, and had it custom ground. I use CompCams for most of my custom grinds, but Bullet had lobes that best matched my desired specs on this one.

Although I designed the cam with the use of headers intended, my software doesn't have a function to simulate tri-Y headers, so this was a bit of a leap of faith for me. I had to enter data like it was a 4-tube design, and it came pretty close. The software predicts flywheel numbers, so they are higher than the numbers obtained on the chassis dyno. I've told a few people that the simulations usually show the rpm to be a bit higher than what is actually measured, but the overall curves tend to be rather accurate. Anyway, here are pictures of the actual chassis dyno results (also shown in the original post) along with the curves predicted by the software (comparing 1.75" headers to log manifolds with a more restrictive exhaust).

[724mula]

Originally Posted by Larry Navarro

I don't know if y'all are aware of my undertaking in production of Tri-Y's. I am in the process of having a jig built to produce headers and if the cost is sustainable, meaning I can make a buck or two from the effort, I will be offering "D" and "O" port configurations. I realize that most everyone would rather spend $300 on a cheap set of headers but there is NO way I could offer such a "bargain". It will be a while before I can get a cost analysis if my efforts are feasible but I wanted to give some "hope" that there will be another option in header choices. Do it once, do it right. "The bitterness of poor quality lingers long after the sweetness of low price is forgotten."

Hey Lee, I need to speak with you about fuel injection. PM you number please, thanks!

Larry, How far out until this becomes reality?

[Sprocket]

and Larry, any chance for a d-port set for '69-'72 GP?

[Lee]

I've known Larry for about 20 years, and if he brings a header (or ANY product) to the market, then I'm sure he is going to put a lot of effort into it, as he has done with his other WFO products. But please, contact him directly

I conducted my own testing, on my own dime, with nobody looking over my shoulder, and nobody knowing the results until I shared them with everyone. If the headers had lost 5hp, I would have reported that as well. Honestly I've always been a bit dubious about tri-Y designs, and this test was partially to satisfy my own curiosity.

[pastry_chef]

Originally Posted by 455GRIN

Didn't realize low compression motor could take advantage of the headers.

A low compression engine can especially benefit from a well matched header.

I currently own EA Plus, EA Pro and Dynomation 6
EAPlus loves crazy long exhaust duration.
Notice the low end difference 3000 to 3500 RPM - chasis dyno vs sim.
Crying for a 3500 stall converter.

[Cliff R]

We've seen improvements near 40hp just from going from one brand of header to another both with the same tube and collector size, but this was on a big CID engine making over 650hp. So for sure how well the headers are made and basic design/construction play a big role with these things.

There are also BIG gains to be had with head pipes and using "X" and "H" pipes before the mufflers. The big CID Pontiac engines for sure respond very well to larger head pipes after the manifolds or headers. The drag strip has shown us a much as .2 and 2mph going from non-mandrel bent 2.5" head pipes with an "H" to mandrel bent 3" pipes with an "H". This doesn't look like much on paper but a pretty significant improvement in terms of power produced in the loaded rpm range.......Cliff

[455GRIN]

Hey Lee, I have some 4 tube headers pulled off a 76 T\A, it would be cool to test a set of 4 tubes to see what if any difference there would be. Also have a set of ram air manifolds that I would lend to the cause. Not sure if you are that curious to do all that work just offering as it would be cool for the Pontiac world

[455GRIN]

Originally Posted by pastry_chef

A low compression engine can especially benefit from a well matched header.

I currently own EA Plus, EA Pro and Dynomation 6
EAPlus loves crazy long exhaust duration.
Notice the low end difference 3000 to 3500 RPM - chasis dyno vs sim.
Crying for a 3500 stall converter.

Chef, you saying Lees combo is begging for a more convertor?

[Lee]

Originally Posted by pastry_chef

A low compression engine can especially benefit from a well matched header.

I currently own EA Plus, EA Pro and Dynomation 6
EAPlus loves crazy long exhaust duration.
Notice the low end difference 3000 to 3500 RPM - chasis dyno vs sim.
Crying for a 3500 stall converter.

The chassis dyno data isn't truly indicative until AFTER 3500. If I floor it under around 32-3300rpm (as indicated on my tach) the transmission will downshift and screw up the data for that run. As such I roll into the throttle, then it takes a bit for the secondaries to fully open.

With a stock torque converter, street traction is minimal as is!

Grin, I appreciate the offer! Skip and Larry N. have made similar offers. Maybe with the next motor, down the road. I've got an appointment to have the pipes and mufflers all changed out next week. All 3", Borla ProXS mufflers, and mandrel-bent 3" tailpipes (from Steve C's old system, thanks Steve!).

[455GRIN]

Is the current 2 1/2 inch exhaust dual mufflers? H pipe? X pipe? Transverse muffler?

You might see another nice boost in power with that upgrade. Look forward to your results.

[Lee]

Originally Posted by 455GRIN

Is the current 2 1/2 inch exhaust dual mufflers? H pipe? X pipe? Transverse muffler?

You might see another nice boost in power with that upgrade. Look forward to your results.

The current system is a cobbled-up job, obviously by a low-quality shop. No X or H, 2.5" pipes making a rather ugly transition into 3" Flowmasters, which then make an even uglier transition into 2.25" tailpipes (which rattle annoyingly at idle).

I may add a Dr. Gas X at a later time.

[Steve C.]

Swapping headers for testing is not easy. If it were it would be of interest to see testing with my old 1-7/8" headers that Lee now has on hand. If memory serves me right Lee is saving them for a future higher HP combo but to see the impact on 'bigger' headers here would be of interest.


.

[unruhjonny]

wow interesting thread;

I found B-man's post (#10) to be the most interesting so far!

[Mister Pontiac]

Originally Posted by unruhjonny

wow interesting thread;

I found B-man's post (#10) to be the most interesting so far!

Agreed. Thanks for that input, B-man!

I looked at a set of 67 manifolds I have, and I notice what you're talking about. For my next build with factory manifolds, I will certainly install the older, "better breathing" ones.

[Larry Navarro]

I appreciate the endorsement Lee and Steve.
Guys, I will gladly entertain other models....IF and only IF I can efficiently and effectively make a buck for my efforts with the 2nd gen crowd. This is my target and largest market for the product as most everyone has modified suspensions where ground clearance is at a premium when considering exhaust systems. I can not speculate on a retail price, hopefully I can have a cost figure based on utilizing premium materials and offering top quality craftsmanship.