H or X CROSSOVER?
- Thread starter CFD244
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I talked with Doug Thorley (RIP) hisself several times many years ago and he could not tell me enough about all of the chassis dyno testing that they did showed little to nothing and that he, like I do thought that it made the exhaust much less crisp. He described it as a blahhhhhh sound. I 100% agree with him. IMO, it takes something away from the exhaust note. He basically thought they were something shiny to get people's money. I must say, he was a real hoot of a guy to talk to.
His ranch was right down the street from me.
Really? He sounded like he was really a cool guy. I would loved to have met him in person. I spoke with him several time back in the early 90s, because that was when they were doing R&D on the revised D Dart headers. I got one of the first of ten sets. This was for my 65 Valiant. To this day, I have not installed a better fitting set of headers.
Are there any downsides? Either H or X? Accessibility?
Pulling transmission, they need to be removed. X can't be used with Gear Vendors.
Thanks! An unplanned trans pull turning into an exhaust drop would be frustrating.
What cpearce said. Pulling the transmission is easier with true duals. And H pipe can cause some interference while the X is dead in the way.
There is that exhaust note sound change which is mostly heard different under a heavy throttle & wise open.
After that, the power difference in most cases is small and you will not know it.
For what it is worth, I like my x pipe but it is coming out this spring. This may be a temporary change with it being returned to service shortly after.
I am swapping my A833 back to my 3.09 first gear model, also a clutch change, this requires it to be pulled. The curiosity of the sound of straight separate pipes is getting the better of me. I will have my local exhaust guy use my x as a template to fabricate new head pipes while I have it apart. It won't be a big cost experiment.
I am swapping my A833 back to my 3.09 first gear model, also a clutch change, this requires it to be pulled. The curiosity of the sound of straight separate pipes is getting the better of me. I will have my local exhaust guy use my x as a template to fabricate new head pipes while I have it apart. It won't be a big cost experiment.
Why would you NOT run a complete OEM stock exhaust system for a A-body of the years that match your Exhaust Manifolds? Including stock OEM Mufflers? They ran GREAT when they were new and totally stock and sounded much better than the 'rattle-crackle' small block Chebby garbage.
How do I know? I'm an OLD PERSON, and I actually HAD a new one.
Bruce
How do I know? I'm an OLD PERSON, and I actually HAD a new one.
Bruce
Hey Bruce. It’s really this simple, the OEM exhaust system was horse power stifling. The sound of the car was what it was and just fine IMO, however, many people want to increase the sound level and/or the sound. Swapping out or changing the muffler and/or the entire exhaust system adds power and mileage. In adsorption to a more pleasing exhaust note which is totally an opinion of the owner/operator of the car.
The cars as delivered naturally ran slightly rich as evidence when the addition of headers were introduced. Simple plug reading are all it takes. The increased power and mileage was also a benefit of the altered air fuel ratio mix.
The sound of the altered exhaust is generally the same from engine to engine, make to make and labeling it as a Chevy thing is very short sighted and wrong since an engine is an engine that makes exhaust sounds ether made whiter or louder etc……
Through the system in place to keep it quite or not.
If your into restoring a car as the only way to do it, that’s fine. But that’s not everyone’s way of doing things and. Since it there car, it’s there car there way. You don’t and we’ll do us our way.
God bless the restored. I do love a great resto.
All hail the hot rodder. I do love modified cars and even more so when it’s outside of normal practices and shows innovation and uniqueness.
Our cars our way.
I have the opportunity to get brand new 3 inch TTI H pipe and tailpipes. The price difference is significant. I will be saving $750 if I buy the 3 inch stuff.
So my question is......Would there be any downside to running 2 1/2 head pipes into a 3 inch exhaust system? Concerned about any goofy sounds or reduced exhaust velocity that would negatively affect performance.
Would love your opinion @VOETOM
So my question is......Would there be any downside to running 2 1/2 head pipes into a 3 inch exhaust system? Concerned about any goofy sounds or reduced exhaust velocity that would negatively affect performance.
Would love your opinion @VOETOM
The OEM system was choked down with the small pipes and sounded like crap in my opinion. They ran GOOD when new but could be improved upon.
VOETOM
Well-Known Member
CD, Pontiac guys do that all the time with the RamAir 2.25 and 2.5" manifolds. The engine wont know the difference and you will hear some more rumbling but I bet not enough to cause any grief!
Many years ago I wondered the same thing about x versus h. Similar specs but more cam. I went x pipe? I called TTI at the time and asked their opinion. At the lower power level per 2.5" pipe it was mostly preference it seems.
The x pipe may be a little quieter with the same mufflers in your case. This is at the cost of killing some of the sound characteristics that individual head pipes have. The H pipe may be between the two as far as sound.
The x pipe may be a little quieter with the same mufflers in your case. This is at the cost of killing some of the sound characteristics that individual head pipes have. The H pipe may be between the two as far as sound.
That is right , I use an H pipe because of the gear vendors , no drone TTI 2.5 woth dyno mufflers out the back past the bumpers
I don't see a downside to going to a 3 inch system, nor should there be any issues with it going up from 2 1/2. I had a full 3 inch from the headers to the bumper, tight fit, but it wasn't a big deal with the TTi pipes.
70SwingerGuy
Well-Known Member
Looks like quite a few people run the TTI full exhaust kits, how is the fit on these?
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Oh course it did. I’m sure it also got 27 MPG’s and ran as clean as today’s cars and lasted 750,000 miles before it needed a spark plug replacing.
Gloating is pointless and makes you sound ridiculous.
Have a great day.
As I mentioned above, I had a 3 inch TTi system, including their step headers and Dynomax Super Turbo mufflers on my 1970 Dart 360/727. It was a tight fit, no question about that, but it is a well designed system, and if you follow the instructions carefully, the result is well worth the effort.
I had the headers on for a couple years before I upgraded the rest of it, but I did the installation on jack stands on a Saturday afternoon. The only thing I found was the right tailpipe needed to be adjusted slightly to prevent it from touching the frame rail over the axle.
Dartsun
Mopar Dude
I’m going with Doug’s headers to TTI 2.5 with an X pipe with Borla Xs mufflers. On a blueprint iron head 408 stroker on my 67 B body. Hopefully be running and driving here by summertime.
'Cuda_ragtop
Woulda, Shoulda, 'Cuda!
FYI, if you didn't see this already.
Holley/Hooker has their A-Body 2.5" for $378.61 and 3" for $371.05
Both full 304 stainless steel X pipe systems have Free shipping if you buy from their EBay Store.
BH23111 2.5" Exhaust System with X Pipe
BH23112 - 3" Exhaust System with X Pipe
I ordered and received one of their 2.5" systems.
They look like this in pictures.
picture of the X Pipe shown in their kit...
This is the actual X pipe that came in my kit.
meh, not a big deal to me, except they didn't fully open the longer pipes where the short pipe connects them.
It's more like a hybrid X/H combination... but I'll have to cut it open to open up the crossover path.
Oh well... I wrote up more with pictures of the inside here G3 Hemi 69 Barracuda Fastback #406
Still a great deal for a complete stainless steel mandrel bent system! And I kind of like the quasi X/H hybrid...
About half the price I paid for my E-Body 2.5" TTi aluminized steel H pipe for Gear Vendors system with Dynomax mufflers but it came with the welded stainless steel out the valance tips too, but it was also 2013...
Holley/Hooker has their A-Body 2.5" for $378.61 and 3" for $371.05
Both full 304 stainless steel X pipe systems have Free shipping if you buy from their EBay Store.
BH23111 2.5" Exhaust System with X Pipe
BH23112 - 3" Exhaust System with X Pipe
I ordered and received one of their 2.5" systems.
They look like this in pictures.
picture of the X Pipe shown in their kit...
This is the actual X pipe that came in my kit.
meh, not a big deal to me, except they didn't fully open the longer pipes where the short pipe connects them.
It's more like a hybrid X/H combination... but I'll have to cut it open to open up the crossover path.
Oh well... I wrote up more with pictures of the inside here G3 Hemi 69 Barracuda Fastback #406
Still a great deal for a complete stainless steel mandrel bent system! And I kind of like the quasi X/H hybrid...
About half the price I paid for my E-Body 2.5" TTi aluminized steel H pipe for Gear Vendors system with Dynomax mufflers but it came with the welded stainless steel out the valance tips too, but it was also 2013...
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Scody21
Just send it
In my car with a 340 am running TTI headers with the H pipe (to clean a GV) to moroso spiral cores and then ran to the back bumper. It sounds super healthy, not much or a drone, can chat in the car without having to yell.
IMO and experiences with the 340 manifolds, the X-pipe is a risk., espeically with a street car. Use a 2.25 or 2.5" to the muffler, 2.5" good mufflers - anything mentioned by Tom, I've also done OK ith Magnaflow. The over the axle with whatever makes a smooth transition and gets over the the axle - no sharp bends right at the muffler exit. Tailpipe diameter not so critical.
As @VOETOM typed in bold, the details of the X pipe make a difference. Dr Gas seemed to work well. @CPDave saw improvement on his (IIRC) Goldfish, but I don't think he had any dyno data. But he did autocross it 10 to 15 times a year.
I put an exhaust system and mufflers with 3" X from Accurate on my 340 with exhaust manifolds. The rest of the system was 2.25 and 2.5" diameter. The car was no more powerful and felt less responsive (than the shop made dual exhaust with 2.5" Dymnomax mufflers). I've posted the dyno pulls from before and after that system went on. BUT there were other changes besides just the X-pipe. So one can not lay the entire blame on the X-pipe - but it was a contributor to the loss of power as well as throttle response.
Here is what I think was happening. The exhaust pulses flow OK until they got to a big space (the 3" X) where they naturally slowed down. Then they try to enter the smaller diameter tubing on the outlet side of the X. But momentum has been lost. The gas sits there until more energy comes along and pushes it into the mufflers and then over the hump and into the 15 psi atmostphere. Great - Not.
Calvin Elston has written gas flow is king, and this is exactly what he's talking about. For efficiency we have to keep the gasses moving away from the exhaust valve for the entire range this engine will be used for.
Larry Meaux has shown that less efficient engines can benefit from slightly larger tube sizes than more efficient engines. Using his program "Pipe-max" we can see the placement of the H-pipe or X pipe is very important. The H-pipe in particular is about tuning the harmonics. Wrong location and it will not help, and may even hurt the rpm range(s) of interest.
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