H-pipe

TwiLighTBluEGT · 06-21-2002, 06:04 PM

I recently had a MAC h-pipe with hi-flow cats professionally installed, and since then, my car sounds better and I think I picked up a couple of highway horses, but sometimes when Iam driving at a constant speed, I can hear rattling from under the car, and when I first start the car and put it in drive and hit the gas to accelerate, it sometimes makes this weird popping sound for the first 1-2 seconds that sounds like it is coming from the engine compartment. I've had the H-pipe on for a good 3 months now, and my car seems to be fine, except for the noises. Just wanted to know if anyone has experienced this with an aftermarket H-pipe.

Unit 5302 · 06-21-2002, 06:16 PM

As far as the popping noise, I'd have to guess your engine is running lean, and that's causing a backfire. Perhaps your fuel injectors are a little weak or need a cleaning.

The rattle is most likely the smog pipe that connects to the air pump being loose.

25thmustang · 06-24-2002, 11:44 AM

I don't know about the ratteling, but my car has the same Mac H-pipe, and I was told that the popping is merely the expanding and contracting of the exhaust. It happens after you let off the throttle, and when I first start my car in the morning it happens. I was told that this is normal, and was okay. Oh ya, mine also did this when I had the stock H-ipie and Flowmaster cat-back.

explicitone · 06-24-2002, 12:14 PM

I also have the mac h-pipe but I have the off road pipe and mine only does it when I let off the go peddle

drtbiker · 06-24-2002, 12:19 PM

i actual heard, i am just quoteing that it is called infire, from the differances in pressure and temps of inside the exaust system and the out side air, i am not sure if that is true but that is what i heard

-rl

ChunkFunky · 06-25-2002, 08:24 AM

I'll just add to the list... I used to get the POPPING in the exhaust when I let off the gas on my olds. I am to understand it's actualy your exhaust igniting as it gets fresh oxygen from the outside air. I used to get it bad when I had a leaky header seal... once I fixed it it went away.. I dont think it's BAD for anything so much.. I thought it sounded kinda neat actualy.. it was a nice grumble when I let off the gas...

-as

TwiLighTBluEGT · 06-25-2002, 10:50 AM

It get the same sound when I let go off the throttle, but the popping sound I am talking about happens when I first press down the throttle, not let off of it. And it sounds like it comes from under the hood, not from the exhaust. I know it is the H-pipe because it happened right after I drove it for the first time after I put the h-pipe on. Another thing, it seems to only do it in really humid weather. When the air is warm and clear, it is fine.

89 Cobra LX · 06-25-2002, 10:58 AM

My stock h-pipe used to rattle. It was the metal-cover that goes over the catalatyc converter. Get under the car and bang around on the h-pipe to find the rattle.

After I installed my offroad h-pipe I had a problem with the smog-pipe bouncing around on the h-pipe. I shortened the tube and used a rubber tube with some clamps to hold it in place better. Another option would be to wrap the pipe with heat-wrap.

drtbiker · 06-25-2002, 11:46 AM

If i actual ride the rpms and then shift it is weird i get the pop when i accelerate. Well i found out what that was when my friend was following me one day it shot a 2ft flame out each pipe. I figured it was maybe the motor running a little to rich. maybe way to rich i have no idea why it does that but who knows lol

-rl

06-21-2002, 06:04 PM	#1
TwiLighTBluEGT Registered Member Join Date: Jun 2002 Location: Massachusetts Posts: 157	H-pipe I recently had a MAC h-pipe with hi-flow cats professionally installed, and since then, my car sounds better and I think I picked up a couple of highway horses, but sometimes when Iam driving at a constant speed, I can hear rattling from under the car, and when I first start the car and put it in drive and hit the gas to accelerate, it sometimes makes this weird popping sound for the first 1-2 seconds that sounds like it is coming from the engine compartment. I've had the H-pipe on for a good 3 months now, and my car seems to be fine, except for the noises. Just wanted to know if anyone has experienced this with an aftermarket H-pipe.

06-24-2002, 11:44 AM	#3
25thmustang Registered Member Join Date: Jun 2002 Location: Kensington CT Posts: 48	I don't know about the ratteling, but my car has the same Mac H-pipe, and I was told that the popping is merely the expanding and contracting of the exhaust. It happens after you let off the throttle, and when I first start my car in the morning it happens. I was told that this is normal, and was okay. Oh ya, mine also did this when I had the stock H-ipie and Flowmaster cat-back. __________________ I am only 17 so this is it for now! 1989 Mustang LX: Cobra Intake, 65mm Tbody, 1.7RR, Mac CAI, 1 5/8 Mac headers, 2 1/2 Mac H-pipe, 2 1/2 Flowmaster Cat-back, 3.73s, BFGoodrich 275/40/17 Drag Radials. 2001 GT leather seats, 17x9 Cobra Rs. Ricer Hater's club: member #48 14.185 @ 97mph (with AOD) 12-19-01

06-24-2002, 12:14 PM	#4
explicitone Registered Member Join Date: Apr 2002 Location: racine ,wi Posts: 691	I also have the mac h-pipe but I have the off road pipe and mine only does it when I let off the go peddle __________________ RUN IT STAIGHT AND RUN IT HARD ________ Novi 2000 60' 1.46 1/4 10.67 mph 126.5 _________

06-24-2002, 12:19 PM	#5
drtbiker Registered Member Join Date: Jan 2002 Location: Mt. Prospect,IL Posts: 474	i actual heard, i am just quoteing that it is called infire, from the differances in pressure and temps of inside the exaust system and the out side air, i am not sure if that is true but that is what i heard -rl __________________ 87-ford-mustang-SOLD! mods: 3:73's, off road h-pipe, b303 cam in gt- 40 motor w/ Power Plus intake, edelbrock 70mm tb & egr spacer, 72mm C&L, bbk long tubes, tremec tranny, centerforce dual friction clutch, upr and lwr CA's 255lph FP and soon more to come.... when i have money again SOME ADVICE Don't do burn outs in reverse it is very expensive New times with dead hook on dr's 13.27@103 with 2.0 60 foots w/100lb system Fastest time to date: 12.8@113

06-25-2002, 08:24 AM	#6
ChunkFunky Registered Member Join Date: Apr 2002 Location: Tustin, CA Posts: 465	I'll just add to the list... I used to get the POPPING in the exhaust when I let off the gas on my olds. I am to understand it's actualy your exhaust igniting as it gets fresh oxygen from the outside air. I used to get it bad when I had a leaky header seal... once I fixed it it went away.. I dont think it's BAD for anything so much.. I thought it sounded kinda neat actualy.. it was a nice grumble when I let off the gas... -as __________________ '89 GT Convertible: TFS TW Heads, TFS Street Intake, TFS Stage 1 Cam, FMS 1.6 RRs, 24# Injectors, Pro-M 75mm MAF, No Name CAI, 3.73s, O/R H-Pipe, FlowMasters, AOD w/ Trans-Go Shift Kit

06-21-2002, 06:16 PM	#2
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	As far as the popping noise, I'd have to guess your engine is running lean, and that's causing a backfire. Perhaps your fuel injectors are a little weak or need a cleaning. The rattle is most likely the smog pipe that connects to the air pump being loose.

06-25-2002, 10:50 AM	#7
TwiLighTBluEGT Registered Member Join Date: Jun 2002 Location: Massachusetts Posts: 157	It get the same sound when I let go off the throttle, but the popping sound I am talking about happens when I first press down the throttle, not let off of it. And it sounds like it comes from under the hood, not from the exhaust. I know it is the H-pipe because it happened right after I drove it for the first time after I put the h-pipe on. Another thing, it seems to only do it in really humid weather. When the air is warm and clear, it is fine.

06-25-2002, 10:58 AM	#8
89 Cobra LX Don Corlione Join Date: Jun 2001 Location: Omaha NE USA Posts: 491	My stock h-pipe used to rattle. It was the metal-cover that goes over the catalatyc converter. Get under the car and bang around on the h-pipe to find the rattle. After I installed my offroad h-pipe I had a problem with the smog-pipe bouncing around on the h-pipe. I shortened the tube and used a rubber tube with some clamps to hold it in place better. Another option would be to wrap the pipe with heat-wrap. __________________ Eric - 89 Mustang LX coupe 5 speed 302-Cobra Intake-GT40p heads-TFS stage 1 cam-FRPP 1.6 roller rockers-3:73 gears-KYB shocks and struts-Eibach Pro-kit-HPM Mega-bite upper and lower control arms-FRPP aluminum driveshaft-16x8 Chrome Cobra Rs R.H.C. #14

06-25-2002, 11:46 AM	#9
drtbiker Registered Member Join Date: Jan 2002 Location: Mt. Prospect,IL Posts: 474	If i actual ride the rpms and then shift it is weird i get the pop when i accelerate. Well i found out what that was when my friend was following me one day it shot a 2ft flame out each pipe. I figured it was maybe the motor running a little to rich. maybe way to rich i have no idea why it does that but who knows lol -rl __________________ 87-ford-mustang-SOLD! mods: 3:73's, off road h-pipe, b303 cam in gt- 40 motor w/ Power Plus intake, edelbrock 70mm tb & egr spacer, 72mm C&L, bbk long tubes, tremec tranny, centerforce dual friction clutch, upr and lwr CA's 255lph FP and soon more to come.... when i have money again SOME ADVICE Don't do burn outs in reverse it is very expensive New times with dead hook on dr's 13.27@103 with 2.0 60 foots w/100lb system Fastest time to date: 12.8@113

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