My new H-Pipe

[OrangeCrush1970]

Just wanted to pass along my observations as I installed an H-pipe on my truck this weekend... What I have bolted to my Mildly built 4-bolt 350 in the breathing department: 4bbl Rochester Q-Jet on an Edlebrock intake, long hookers w/ 2 ½” collectors to 29 ½” L / 2 1/2” in / out Cherry Bomb glass packs that turn down in front of my rear axle. (I have a long bed w/ the coil spring set-up).

SO, obviously this was a relatively loud system. One of my neighbors loved it, the rest were nice about it, but I could tell that it was a bit too much in the mornings. Aside from my expected performance gains, I wanted to quiet things up a bit. Personally, I love the sound of headers and straight pipes, you can’t beat it, but I can’t risk being ‘that guy’ in the neighborhood.

I went to summit and picked up one of their $32 h-pipes. When it arrived in the mail, it looked like my 3 yr old nephew had welded it together. I highly suggest spending a few more $$ and go w/ a name brand, hooker, headman, etc. From the research that I carried out I found that I needed to install the H-pipe as close to the collectors as possible. It ended up finding it’s home about 12” back from the collectors, or about 2.5” behind the front cross member just behind the slip yoke on my tranny. I will post pics later-

The Pros: It is certainly mild. There is better throttle response, better low end torque as well as a last push that wasn’t there at about 4800 rpm’s( I probably need to re-tune the Q-Jet a bit), and overall my engine is running a bit smoother / more balanced.
The Con: I lost my cam loop, or at least I cannot hear it anymore. The sound that I loved so much is gone. It had been compared to my uncle’s ’67 Chris Craft w/ a Chrysler 340…I KNOW, Im not a Chrysler fan either, but the sound of that boat on the water is heaven.

To sum things up Im happy with the performance gains, nice and smooth, but it changed the aggressive chop / loop that I enjoyed so much.

As for anyone else who has also run this set up, can you give me some suggestions for mufflers that will compliment the H-pipe? I just feel that the packs have lost their effect.

Im sure that I’ll get antsy and end up taking it off in a few weeks!

Thanks-

[JAKES 68GMC]

I was thinking of an H-pipe, but I don't want to lose the little cam lope I have either.

[chev74]

it sucks that you tried to do something nice for the neighbora dn it ended up biting you from behind... too bad

[yenko427]

I have a home made h pipe on my truck and all most the same setup but I have my exhaust coming out the side before the wheels with Full Boar mufflers. Have you re check you timing you can maybe retired it a little a adjust your idle. I still have a little cam loop but I would rather have the performance. And my wife says my truck is to load but man it sound good.

[matthufham]

i'm installing an h pipe this weekend in the same location after my tranny.

[dan42]

The Con: I lost my cam loop, or at least I cannot hear it anymore. The sound that I loved so much is gone. It had been compared to my uncle’s ’67 Chris Craft w/ a Chrysler 340…I KNOW, Im not a Chrysler fan either, but the sound of that boat on the water is heaven.

Lord, I thought I was the only one that loved that sound - or the sound of the old inboard Centurys, at an idle, burbling in the water - it's sweet music. My '70 sounds a little like that (it has an H pipe) but my '67 has straight duals with no cam, and it kinda sounds like there's a hole in a regular muffler. Not too impressive.

[68C15]

take off the H pipe and the 29" pack. give it a pair of 12" packs installed backwards and put them as far forward as possible. this should bring back the sound. hehehe

nothing as sweet as a bark and cackle IMO

[pmpski_1]

Does it still sound good when you get on the gas?

[Twistedsteel]

Damn that sucks I know how you feel I love loud pipes. I had an h pipe on mine and when I got my exhaust redone I told him I wanted it loud so he did not put one back in. Right away I noticed power loss, and it also wasn't as loud as my previous exhaust. It still sounds good at idle but when you get on it it's not as loud.The sound difference is probably attributed to the fact that it used to have 2.5 to the muffler and then out the muffler. And now it's just 2.5 all the way.

Albie

[space]

Same thing happened to me with FM 40's

[OrangeCrush1970]

Originally Posted by yenko427

I have a home made h pipe on my truck and all most the same setup but I have my exhaust coming out the side before the wheels with Full Boar mufflers. Have you re check you timing you can maybe retired it a little a adjust your idle. I still have a little cam loop but I would rather have the performance. And my wife says my truck is to load but man it sound good.

I was thinking about putting some 45 degree pipes on behind the packs and exit in front of the wheels. This should seperate the sound a little more. Currently my packs are running just inside and below my frame rails, so each pack does not sounds very distinct. Thanks, I'll let you know if I try this. I actually had the same setup b/f with the staright pipes, but I had 90 degree bends and I felt like that caused too my back pressure.

[OrangeCrush1970]

Originally Posted by pmpski_1

Does it still sound good when you get on the gas?

It sounds good, but different. Not the vintage straight pipe sound as before. I dont feel like I win the 'who's exuast sounds better' when another guy pulls up next to me in his mustange or truck-

Sounds a bit more sporty...just not as aggresive.

[special-K]

I`ve never run a cross-over.No one ever used to.I know things vary,but the first thing that goes on a Harley is the crossover.Nothing runs as good a true duals on a Harley.No crossover on race vrhicles either.But,bottomend is a non-issue since they dump at full throttle.Boats and roundy-round racing is all about staying in the power curve,too.I guess crossovers are best for street.Unless untimate performance isn`t such a big deal.I always thought my stuff ran great.

[OrangeCrush1970]

Originally Posted by special-K

I`ve never run a cross-over.No one ever used to.I know things vary,but the first thing that goes on a Harley is the crossover.Nothing runs as good a true duals on a Harley.No crossover on race vrhicles either.But,bottomend is a non-issue since they dump at full throttle.Boats and roundy-round racing is all about staying in the power curve,too.I guess crossovers are best for street.Unless untimate performance isn`t such a big deal.I always thought my stuff ran great.

I agree with you, I feel like my power curve doesnt spike so much as before. There's a ton of pull on my low end and instant throttle response, but it seems like things got a little flat in my 3500 to 4500 rpm range.

[OrangeCrush1970]

Originally Posted by dan42

The Con: I lost my cam loop, or at least I cannot hear it anymore. The sound that I loved so much is gone. It had been compared to my uncle’s ’67 Chris Craft w/ a Chrysler 340…I KNOW, Im not a Chrysler fan either, but the sound of that boat on the water is heaven.

Lord, I thought I was the only one that loved that sound - or the sound of the old inboard Centurys, at an idle, burbling in the water - it's sweet music. My '70 sounds a little like that (it has an H pipe) but my '67 has straight duals with no cam, and it kinda sounds like there's a hole in a regular muffler. Not too impressive.

That sound is the best....
I have a small Erson off road cam, not too agressive but it's deffinatly there.

[Billla]

The purpose of a crossover is to cancel out the differences in the pulses...so I'm not too surprised that the lope cancelled out since by definition they're out of phase with each other (seperate banks).

Sounds like it's time for a Thumpr cam '-)

[special-K]

Billa,you win a cantelope for that answer.Much tastier than a canteloop.