3" vs 2.5" depate
I just finish reading the 3" post and there seems to be alot of confusion on what works for you. Im going to try to done learn ya.
3" or 2.5"?
A 2.5" system will flow plenty. You can put down 400hp with a 2.5" system, this is a fact. Now at 400hp, if you where to swap out your system for a 3", then you WILL yeild more HP, 10+ hp from swapping to a 3" is not far fetched.
A 2.5" system will flow plenty, but the current catback systems out do not cut it though and this is why:
The american and european exhaust systems utilize slip fit setups where as the asian market uses flanges. I do not like the slip fit setups because they are difficult to disassemble being that the pipes are clamped to each other. It also makes it difficult to get a full upgraded exhaust that you can missmatch from different manufactures.
When you upgrade your exhaust, you will have a bottleneck in it. The great thing about the flange designed systems is that you can have a 3" catback bolt up to a 2.5" downpipe etc. For example, on an mkiii T supra, you can install a 3" Dp which will bolt on to your stock catalytic conveter. A racepipe will also bolt on to your stock exhaust system even though one is a 3" and the other is a 2.25". Now when you upgrade your catback to a 3", you will have a full 3" system with out having to modify it. This allows you to get X brand DP and mate it to a y catback brand.
The current catback systems currently out all have a 2.25" bottleneck. So your going from a 3" DP (assuming you have one) down to a 2.25" bottleneck that chokes your system then back into a 3" or 2.5".
Those of you who already have a Dp and purchase a catback, I suggest you take it to a muffler shop and have them cut the bottleneck. Have them take a 2.5" pipe and expand one end to a 3". This will alow you to get a smooth transition into a 2.5". Going from a 3" to a 2.25" then back to a 2.5" is a pretty poor design. But this is what the manufactures and customers have to deal with unless they purchase a complete 3" system from a manufacture.
What size exhaust you want sould be based on how much HP you want to yeild. A true 2.5" is plenty, but it will eventualy become restrictive. It all depends on what you want. Purchasing a 3" is purchasing insurance for future mods.
The more HP you make, the more HP you will get out of your exhaust system.
If you want to make the most HP, just take a straight 3" DP and leave it open. To loud for me and not practicle though. But that will yeild the most HP.
OH,
I remember an SP supra that had about 900+ HP to the wheels with a 3" exhaust. When they swapped it out for a 4", then gained about 100 HP with that alone!
I just finish reading the 3" post and there seems to be alot of confusion on what works for you. Im going to try to done learn ya.
3" or 2.5"?
A 2.5" system will flow plenty. You can put down 400hp with a 2.5" system, this is a fact. Now at 400hp, if you where to swap out your system for a 3", then you WILL yeild more HP, 10+ hp from swapping to a 3" is not far fetched.
A 2.5" system will flow plenty, but the current catback systems out do not cut it though and this is why:
The american and european exhaust systems utilize slip fit setups where as the asian market uses flanges. I do not like the slip fit setups because they are difficult to disassemble being that the pipes are clamped to each other. It also makes it difficult to get a full upgraded exhaust that you can missmatch from different manufactures.
When you upgrade your exhaust, you will have a bottleneck in it. The great thing about the flange designed systems is that you can have a 3" catback bolt up to a 2.5" downpipe etc. For example, on an mkiii T supra, you can install a 3" Dp which will bolt on to your stock catalytic conveter. A racepipe will also bolt on to your stock exhaust system even though one is a 3" and the other is a 2.25". Now when you upgrade your catback to a 3", you will have a full 3" system with out having to modify it. This allows you to get X brand DP and mate it to a y catback brand.
The current catback systems currently out all have a 2.25" bottleneck. So your going from a 3" DP (assuming you have one) down to a 2.25" bottleneck that chokes your system then back into a 3" or 2.5".
Those of you who already have a Dp and purchase a catback, I suggest you take it to a muffler shop and have them cut the bottleneck. Have them take a 2.5" pipe and expand one end to a 3". This will alow you to get a smooth transition into a 2.5". Going from a 3" to a 2.25" then back to a 2.5" is a pretty poor design. But this is what the manufactures and customers have to deal with unless they purchase a complete 3" system from a manufacture.
What size exhaust you want sould be based on how much HP you want to yeild. A true 2.5" is plenty, but it will eventualy become restrictive. It all depends on what you want. Purchasing a 3" is purchasing insurance for future mods.
The more HP you make, the more HP you will get out of your exhaust system.
If you want to make the most HP, just take a straight 3" DP and leave it open. To loud for me and not practicle though. But that will yeild the most HP.
OH,
I remember an SP supra that had about 900+ HP to the wheels with a 3" exhaust. When they swapped it out for a 4", then gained about 100 HP with that alone!
