Evil94

curious.... Whats the diff between TBE and downpipe+test+ catback exhaust? is TBE slightly better or what?

RoadSpike

iTrader: (5)

TBE: Turbo back exhaust
(means downpipe + test pipe + cat back exhaust parts) sometimes test pipe is not included or replaced with high flow cat.

So there is no difference though I will add that a TBE usually comes at a slight discount to purchasing the parts separate.

Evil94

icic..thats what i thought too haha.. thx =)

Turbodemon

iTrader: (2)

bump

EGbeater

iTrader: (35)

Not contesting your statements, but can you provide a link to these test results between a ported OEM manifold and aftermarket tubular manifolds?

Also, anyone have any direct experience with vendors/recommendations/dyno results for exhaust manifold porting?

I see PPI (http://www.paradigmperformance.net/p...manifold.html), Buschur (https://secure.buschurracing.com/cat...575ade3daf0cdc) and MIL.SPEC (https://www.evolutionm.net/forums/sh...d.php?t=330262) as the primary vendors for exhaust manifold porting.

RoadSpike

iTrader: (5)

Sure my data came from the testing done by Buschur in 2005 when he was going through manifolds and the cheap 02 housings.

https://www.evolutionm.net/forums/sh...22full-race%22

hytek369

iTrader: (81)

this is a really great guide. thanks.

can someone elaborate more on cams and cam gears?

RoadSpike

iTrader: (5)

So what do you want elaboration on besides anything obvious and not posted in the cams section I wrote?

hytek369

iTrader: (81)

i searched for your posts. can't seem to find it. can you point me in the right direction?

basically, want to know the pros and cons of each cam 264, 272, 280, idle issues, etc.

RoadSpike

iTrader: (5)

Well in this thread you wont see my post directly the OP of this thread added it in from a PM session. This question is pretty vague so prepare yourself for a rather large post .

Besides the obvious number on the cam 264 and so on you need to consider the valve lift the cams produce. It should seem pretty obvious that if you lift up the valves more then more air will rush into the chamber. Now combine that with how fast they open and how long they say open for and you'll get an idea why some cams like the JUN 272 are VERY AGGRESSIVE and why the HKS 272's are not.

What is Aggressive?:
Lets use the GSC "S" series cams as the example here for how duration and lift effects the power. With the S1 cams you have a 268/266 cam combo with just 10.5 mm lift this cam would be effective from 3000-8000rpms. The S2 cams have even larger lifts (11.2/11.1) and durations (274/272) making them quite aggressive pushing the power band to the right 4000-9000rpms. S3 cams have what i consider insane lift (11.5mm) and large durations (290 or 280) making their application strictly geared towards all out power, don't expect these to idle with no effort.

As you make the cam more and more aggressive what happens is at very low engine speed ,IE idle, you start to loose running vacuum. This is because of valve overlap which means simply the duration of time when the exhaust valve is still open and the intake is opening. Some where in the 20's or 30's some genius figured out if you open the valves when the exhaust is being pulled out it improves performance however if you do this too much then your idle suffers since the charge of air will be diminished if you leave the exhaust valve open for too long air escapes out into the exhaust. However on the flip side at higher rpm overlap helps improve the air charge into the combustion chamber making more power.

Now you may believe that HKS 272's are aggressive based on the S2 specs but really they aren't because the lifts they produce are much less than a S2 cam. The lift of HKS is 10.8mm intake and 10.2mm exhaust, this shows it has higher lift than a s1 on the intake making the intake more aggressive and lower lift on the exhaust making it less aggressive there. This kind of combination would make less midrange power but come into range at slightly higher rpm ranges than the S1 cams. Now as a curve ball the JUN 272's are very aggressive with lifts around or maybe even higher then the S2 cams making their power band along the lines of the s2 cams. If your purchasing cams from a shop and your confused as to how aggressive they are I suggest just calling them and asking them questions.

Cam Selection:
If you plan on sticking with a turbo from stock up to gt30r series then the kind of cam selection that would benefit you the most would be a moderate to very light cam in terms of aggressiveness. There are many cams out there anything along the lines of hks 272/264, S1, or some other lower lift 272's out there would be fine.

If you plan on stepping up the turbo to a gt35r and beyond then larger cams will certainly add power in those turbo's effective ranges 4k+ rpms. If you plan on trying to beat the current HP records then maybe the S3 cams are right for you :P

The only other notes i can give is that the larger the duration of the cam then the larger the overlap will be and thus your idle will need more adjusting. If your going for aggressive cams your going to need to get a tuner to help you dial them in .

Cam Gears:

The idea behind cam gears is very simple, basically what your doing with cam gears is changing either the center location of the cams, the overlap, or both. So with the gears you can fine tune your cams shifting the power band from left to right but usually at the cost of performance somewhere else .

apeximprt2nr

iTrader: (7)

Gsc S2 cams are great cams witth a gt35r or larger turbo!

chaotichoax

iTrader: (149)

updated with more info

thanks RoadSpike

LakerRaider

iTrader: (12)

why does it seem like every mod has a problem? i am completely stock,and would like to start modding, but i dont have enough money to keep payin for repairs and i do not know much on working on my car. i know ill be voiding my warranty if i mod (duh), which makes it worse because ill lose out on warranty work if anything goes wrong. Im guessing everyone who mods thier car has a lot of money because they have the money to make an experiment out of thier car?

my car is a dd so if anyone can point me in the right direction to getting reputable parts and installation methods (to reduce spending money on problems of any mod i get) it would be greatly appreciated. say i had $500 to blow, what would you guys get? how about $1000 to blow?Thanks

chaotichoax

iTrader: (149)

you have to pay to play that's the bottom line

$1,000 - tbe, mbc, boost gauge, licp, tune, open intake if you want some noise

**if you have a viii get a walbro fuel pump also

Chemwarrior

iTrader: (14)

If you are also concerned about voiding out your warranty then keep your stock parts that you replaced with aftermarket ones and if you need to take your car to the dealership then just switch them back. You will hear a lot of grumblers out there saying this is illegal and unethical but if Mitsubishi was more warranty friendly we wouldn't have to do this or if you could find a dealership that is mod friendly is another recourse.