Down Pipe: HKS or RMR. Which one is better?
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Joined: May 2003
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From: Buffalo, NY
Originally posted by lil'evil_evo
If you do not plan on adding a ton of power go with HKS. With 2.75 you will not loose that much low end power like with the RMR. With the larger size of the RMR you will gain more top end power. I would buy the HKS only because I do not plan to have 400 plus whp. I also like HKS much more then RMR.
If you do not plan on adding a ton of power go with HKS. With 2.75 you will not loose that much low end power like with the RMR. With the larger size of the RMR you will gain more top end power. I would buy the HKS only because I do not plan to have 400 plus whp. I also like HKS much more then RMR.
Here's an exerpt from Cobb's website...read it and PLEASE learn. there are too many myths going around about smaller diameter and more low end...
One thing I do want to explain before I get too far into this is backpressure. I hear "You need backpressure to make torque." all the time. And it even comes from "tuners" as well as customers. This is flat out not true. Before I arrived into the company of true tuners I fell into the same trap myself. The reality is that backpressure is the enemy. You want to keep it as low as possible. What you do want is to keep velocity up. However doing the things that keep velocity high involves slightly more backpressure under some conditions. You want to keep the gasses moving as quickly as possible to make both good torque and top end power. The perfect exhaust system would keep the gasses moving as fast as they did coming out of the cylinder and have zero backpressure. However this is impossible to achieve in the real world.
Originally posted by sophis
No, the HKS downpipe is neither 2.75" or 2.65" but 65mm or 2.559".
No, the HKS downpipe is neither 2.75" or 2.65" but 65mm or 2.559".
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From: ORANGE COUNTY
Damn, I am still in the air of what to get. The smaller HKS or the larger RMR. I know if I go for a bigger turbo, the larger DP is recommended. I will probably go for the RMR.
Does anyone know if you need to put spacers for the lower brace on the HKS?
Does anyone know if you need to put spacers for the lower brace on the HKS?
Maybe we are measuring different. Are you going from inside to inside or from outside to outside. I have no idea where the 2.75 is going from this is just what I was told. I would think 2.75" is from outside to outside, so you would be correct if this is the case my bad.
Just get the RMR since it is a true 3" and I think it's a little cheaper in price.
sophis I would agree 100%, but from everyone I have talked to in person about the best exhaust they all say depends on power so I also go by this. For example my roommate has a 380 whp talon and he tried 2 DP's one 2.5" and the other 3". He noticed just what I said about low end power and high end power. I'm not saying your wrong at all. This is just my 2 cents.
sophis I would agree 100%, but from everyone I have talked to in person about the best exhaust they all say depends on power so I also go by this. For example my roommate has a 380 whp talon and he tried 2 DP's one 2.5" and the other 3". He noticed just what I said about low end power and high end power. I'm not saying your wrong at all. This is just my 2 cents.
The RMR pipe fits fine with the stock cat and it comes with a heat shield for the oil pan. It does require a new underbrace, but you will be glad you bought a replacement for the dinky stock ones anyway. As for the stock DP, take a look on my profile pics and you can see how nasty it is. I don't care if it's 2", 3", 5" whatever - you don't want that thing on your car!
Originally posted by Chris in HB
The RMR pipe fits fine with the stock cat and it comes with a heat shield for the oil pan. It does require a new underbrace, but you will be glad you bought a replacement for the dinky stock ones anyway. As for the stock DP, take a look on my profile pics and you can see how nasty it is. I don't care if it's 2", 3", 5" whatever - you don't want that thing on your car!
The RMR pipe fits fine with the stock cat and it comes with a heat shield for the oil pan. It does require a new underbrace, but you will be glad you bought a replacement for the dinky stock ones anyway. As for the stock DP, take a look on my profile pics and you can see how nasty it is. I don't care if it's 2", 3", 5" whatever - you don't want that thing on your car!
so true this post makes the most sense.
Ultimate Racing
why not try the ultimate racing dp and high flow cat? i am very happy with it and it does not require any adjustment of underbracing. i have the Ultimate Racing 3"dp and cat along with the RMR 3" catback. this setup is under $1000 and yielded a 23hp gain and 14.9lps of torque. the Ultimate Racing is equal in price and requires no modifications. just my 2cents
I have the HKS downpipe and did measure it before I installed it. There is no way that thing is 2.75". If you want to be even more sure, Gruppe-s has the HKS part number as HKS-3306-SM002. Check out HKS's Japan site: http://www.hks-power.co.jp/products/.../sfp_data.html The EVO VIII dp and EVO VII dp are the same, the part number is the same and it lists the downpipe as 65mm.
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From: ORANGE COUNTY
It sounds like, I should go 3". Alot of debate between the HKS and RMR. Now I am thinking, between the stock DP and the HKS DP, might only be a 1/4". I will go 3"