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Discussion Starter #1
Has anyone used Tri Y headers?

I'm planning on a 5500 rpm redline on the KB2200 Windsor 5.0 and wonder if they would work better than 4 into 1 for me?
 

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I have them on my dad's 65 fastback, been on there for 15yrs. They were a no name ebay special. Fit really good, but only had 2.25 collectors, which was ok for a stock headed 289.
 

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What is the reasoning behind using Tr-Y headers?
 

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Discussion Starter #5
What is the reasoning behind using Tr-Y headers?
I'm curious if anyone on this site has used them with a blower and what their results were. There is so much information on blower engines with short, mid and long tube 4 into 1, but I haven't found anything with Tri-Y's.

4 into 1 long tube headers tend to have the greatest benefit in the mid to high end rpm ranges.

Tri-Y tends to come into its own in the low to mid rpm range.

Most street blowers seem to be used in the low to mid rpm ranges and I'm wanting to have my power in the 1200-5500 rpm range.

Ceramic coated, long tube 4 into 1 headers that will fit my 68 Mustang and clear a T-56 6 speed will cost a little over $1000.

Ceramic coated Tri-Y will cost a little over $600 and a few hundred less if I buy an uncoated set and have them ceramic coated locally.

If I decide to make my own headers, Tri-Y's would be easier to make than long tube 4 into 1.

I'm not suggesting that one type will be better for me than the other, because I really do not know. All of the headers I have bought since the 70's were long tube 4 into 1.
I have never used Tri-Y's or a Blower.

I have rode in a and driven 400-500 hp big block cars and loved the power everywhere feeling. That is what I'm looking for with my fastback. If I'm looking at a 20 hp/tq loss by going with Tri-Y's, I'm okay with that and doubt I will really notice the difference and could use the extra $400-$500 towards the rest of the exhaust.

If I'm looking at losing 40 hp/tq, well I guess it will be time to bite the bullet spend that $1000 plus.

Thanks
Ken
 

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With a KB 2.1 blower, you dont need to worry about torque. PERIOD. With instant max boost, you will find a abundance of torque from off idle to max rpm. The KB superchargers, like all positive displacement S/C, make boost based on load, so WOT is not necessary to have boost. Low rpm torque is not a problem. That 302 will feel like a big block. As an example: my racecar has a 2.8l lq KB s/c....at 2,400 rpm at WOT on the trans brake, my engine makes 14+psi of boost. A 2.1 at the same rpm, if pullied the same will make 14 psi at the same rpm. In fact, off idle, going WOT will give you max boost for what the s/c is pullied for. Do you think that your car can hook the street tires up with 10 psi at 1,200 rpm? Yeah, did not think so. Put 3.27:1 gears in the car, pulley the s/c for 10-12 psi and plan on buying new rear tires. Please use long tube 4 into 1 headers. You should not intentionally choke the engine with a Tri-Y when using a KB s/c.
 

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Discussion Starter #7
. Put 3.27:1 gears in the car, pulley the s/c for 10-12 psi and plan on buying new rear tires. Please use long tube 4 into 1 headers. You should not intentionally choke the engine with a Tri-Y when using a KB s/c.
Thanks again for your help, I'll go for the Ford Powertrane Application stepped headers.

3.27:1 gears: I had been kicking around going with gears in the 3.50:1 range, but you got me thinking and playing with a gear ratio calculator and then thinking some more.

My T-56 ratios are 2.97, 2.07, 1.43, 1.00, 0.80, 0.62

3.27:1 at 5500 rpm in 1st=43 mph, 2nd=62 mph, 3rd=90 mph, 4th=128 mph 5th=160 and 6th=207
6th gear @ 60 mph= 1600 rpm

3.00:1 @ 5500 rpm = 1st=47, 2nd=67, 3rd=98, 4th=140, 5th=175, 6th=226
6th @ 60 mph=just under 1500 rpm

Okay, so lets forget the redline 5th and 6th gear mph. Even if the car could (it Won't) I won't, but look at the 60 mph rpms at 60. 1600 rpm and sub 1500 rpm.

Along with the power, I am wanting 20+mpg while cruising on the freeway.

Obviously, within reason, less rpm = better mpg.

How did your street car run when cruising at 1500 rpm?
I'm assuming that you had a 5 speed, what was the lowest rpm that you would cruise in 5th before you would then shift to 4th to bring up the rpm's?

Do you think that 3.00:1 would be too high for my car? 3rd gear from 25 to 98 mph could be fun and 4th from 35 to 120 mph would be a blast with a lot of torque.

If I reduced my goals to just 2, they would be 20+ mpg when cruising and into the 12's in the 1/4, do you think this is possible with these gears?

Pulley for 10-12 psi
With the 72cc chambers I will be somewhere in the area of 8.0:1 compression.
Do you think I can run 92 octane pump gas without pulling the timing, using A2A intercooler or water injection while pullied for 12 psi?

Thanks again.
Ken
 
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