Is rattle same as rasp? I have a tin rattle when I accelerate.
#16
06-29-2006, 05:19 PM
Originally Posted by ISMSOLUTIONS
There are few differences in headers. You either have equal length, I call them spaghetti headers, or you have some sort of other shorty style, pretzel headers.
The real functionality difference is equal length will give you the best top end speed and HP. The shorty style will be for most of us street race ands 1/4 mile guys and gals.
Quality speaks for itself in the flanges - thickness and weld quality. Are the welds inside the flanges or outside - inside is best - but are there stress relieving welds on the outside as well? Those are VERY important details.
Quality speaks to mandrel bent pipes and size of pipe, not crushed bends to hammered areas as well. Welds should be clean as well.
Quality speaks to the collector. Is it stainless or welded inside, etc.
Quality speaks to the coating, polished or not, etc.
Headers on our cars are not great performance enhancers unless you wildly modify the car for NA or go with a SC. Otherwise they are sound enhancers, that cost a pretty penny. They will cost you TQ and give you minimal HP at BEST - but the sound is awesome!!!
So, be wary of what you buy and why. Companies like Strup and DC Sport for under $500 for ceramic coated versions are there and sell mass quantities for a reason.
Rick
The real functionality difference is equal length will give you the best top end speed and HP. The shorty style will be for most of us street race ands 1/4 mile guys and gals.
Quality speaks for itself in the flanges - thickness and weld quality. Are the welds inside the flanges or outside - inside is best - but are there stress relieving welds on the outside as well? Those are VERY important details.
Quality speaks to mandrel bent pipes and size of pipe, not crushed bends to hammered areas as well. Welds should be clean as well.
Quality speaks to the collector. Is it stainless or welded inside, etc.
Quality speaks to the coating, polished or not, etc.
Headers on our cars are not great performance enhancers unless you wildly modify the car for NA or go with a SC. Otherwise they are sound enhancers, that cost a pretty penny. They will cost you TQ and give you minimal HP at BEST - but the sound is awesome!!!
So, be wary of what you buy and why. Companies like Strup and DC Sport for under $500 for ceramic coated versions are there and sell mass quantities for a reason.
Rick
Headers won't cost you tq
#17
06-29-2006, 05:22 PM
If your keeping your stock exhaust:
I rec that you get a y-pipe without flexers. Also, get resonated testpipes or cats. For headers, I chose DC Sport Cermic Coated for mine and am perfectly happy with them, after testing others. I may also go the route of a custom set - but look at my mods - different reasons for that.
If your putting a catback on the car:
Same paragraph as above, just start after the y-pipe
I rec that you get a y-pipe without flexers. Also, get resonated testpipes or cats. For headers, I chose DC Sport Cermic Coated for mine and am perfectly happy with them, after testing others. I may also go the route of a custom set - but look at my mods - different reasons for that.
If your putting a catback on the car:
Same paragraph as above, just start after the y-pipe
#18
06-29-2006, 05:27 PM
Originally Posted by 99atlantic
Headers won't cost you tq
Unless you are building decently serious NA (cams and such) or SC spec mods or more...you will loose TQ on general NA stock-based cars with general CAI and catbacks....yes you will. You will gain some HP, some combo's yield more HP, and a little less TQ loss....but the real gain is sound overall and some mid-range boost, mostly unnoticeable. The sound effect makes you think more is happening.
Rick
#19
06-29-2006, 05:46 PM
OK from what I hear it may very well be my catback too that's causing the tinny rattle. Luckily my HKS Ti is delivered next week so hopefully after install the sound will be gone.
Also it's probably asked a thousand times...but resonated means what? I have kinetix HF cats...are they resonated?
so hopefully after install the sound will be gone.Also it's probably asked a thousand times...but resonated means what? I have kinetix HF cats...are they resonated?
#20
06-29-2006, 05:54 PM
Originally Posted by fireblade
OK from what I hear it may very well be my catback too that's causing the tinny rattle. Luckily my HKS Ti is delivered next week so hopefully after install the sound will be gone.
Also it's probably asked a thousand times...but resonated means what? I have kinetix HF cats...are they resonated?
so hopefully after install the sound will be gone.Also it's probably asked a thousand times...but resonated means what? I have kinetix HF cats...are they resonated?
Resonators perform better than CATS, but there are also advantage to CATS - like no fuel smell, etc.
Rick
#21
06-29-2006, 07:55 PM
Originally Posted by ISMSOLUTIONS
How many different sets and combinations have you personally tested and dyno'd, under different mod configurations?
Unless you are building decently serious NA (cams and such) or SC spec mods or more...you will loose TQ on general NA stock-based cars with general CAI and catbacks....yes you will. You will gain some HP, some combo's yield more HP, and a little less TQ loss....but the real gain is sound overall and some mid-range boost, mostly unnoticeable. The sound effect makes you think more is happening.
Rick
Unless you are building decently serious NA (cams and such) or SC spec mods or more...you will loose TQ on general NA stock-based cars with general CAI and catbacks....yes you will. You will gain some HP, some combo's yield more HP, and a little less TQ loss....but the real gain is sound overall and some mid-range boost, mostly unnoticeable. The sound effect makes you think more is happening.
Rick
Wait - maybe with your fast intentions exhaust i'll gain 50rwhp from my headers!!!!!!!!!!!!!!!!!!!!!!!!!!11111111111111111 1111oneoneoneoneoneoenoeoenneoneonenoeneoeneoneone
#23
06-29-2006, 08:37 PM
Originally Posted by 99atlantic
Wait - maybe with your fast intentions exhaust i'll gain 50rwhp from my headers!!!!!!!!!!!!!!!!!!!!!!!!!!11111111111111111 1111oneoneoneoneoneoenoeoenneoneonenoeneoeneoneone
Honest as I've always been
Rick
#24
06-29-2006, 11:15 PM
The tin can rattle is the nature of the VQ series motor and running a more open exhaust. We had the same sounds coming from VQ30 and VQ35 Maximas. The source? It's related to the firing order of the VQ, the exhaust pulses created in the lower rpms (~2000-4500rpms), and the thickness of the piping. All aftermarket exhausts and cats use significantly thinner and lighter grades of metal for the piping. This adds noise and greatly reduces the thermal efficency (not a good thing) of the exhaust.
#25
06-29-2006, 11:18 PM
#27
06-30-2006, 01:16 AM
Join Date: Dec 2004
Posts: 923
Likes: 0
Received 0 Likes
on
0 Posts
#28
06-30-2006, 01:58 AM
Originally Posted by DaveB
The tin can rattle is the nature of the VQ series motor and running a more open exhaust. We had the same sounds coming from VQ30 and VQ35 Maximas. The source? It's related to the firing order of the VQ, the exhaust pulses created in the lower rpms (~2000-4500rpms), and the thickness of the piping..
Originally Posted by DaveB
All aftermarket exhausts and cats use significantly thinner and lighter grades of metal for the piping. This adds noise and greatly reduces the thermal efficiency (not a good thing) of the exhaust.
Stock piping is basically 16 gauge - though metric, actually closer to 15 gauge. Many aftermarket systems use 14-16 gauge stainless, compared to aluminized piping, which is actually higher quality and better at sound conditioning and pulse absorption. Only the extra light system use 18 gauge - and the drone and noise come from the cheap muffler.
Exhaust pulse cancellation is contingent on speeding up and/or slowing the pulse in direct relation to the design of the muffler, its ability absorb and reflect that pulse back unto itself for cancellation, or the systems ability to just allow it to flow through.
A tin can rattle in exhaust is not inherent from an engine design. It is the result of either something resonating, loose or broken. Adding headers or high flow cats or testpipes can and will disrupt the catbacks tuned balance, but it will not cause a tin can sound. Resonation, bad CATS, bad or cheap resonators/CATS/heatshields will.
Do keep in mind as well, you are passing much more exhaust sound through a system that was not designed to filter it to begin with...so you will hear more than you did before. Exhaust gases could also be hotter than before an wear mufflers and resonator out, causing the noises. Many header and resonator/CAT manufacturers warn against using their products with headers and such as well as damage may occur.
Rick
Last edited by ISMSOLUTIONS; 06-30-2006 at 02:04 AM.
#30
06-30-2006, 09:45 AM
I will say that I have also heard the VQ35 make this sound. BEE's in the CAN and its definitely not caused by the pipes. It's coming from the engine itself.
The ypipes on the Maximas replace the cats/flex pipes and they use to not even have a flex pipe in them. All it was is SS piping and nothing else to create this noise. It is possible this noise is what the Maximas had.
The ypipes on the Maximas replace the cats/flex pipes and they use to not even have a flex pipe in them. All it was is SS piping and nothing else to create this noise. It is possible this noise is what the Maximas had.