migueralliart

iTrader: (10)

Here is the link CUTOUT

I think I will go with the 2.5 or 2.25 cutout not sure why ... so my downpipe is gonna be 2.5 and then the cutout and then it reduces to stock cat ..
I am thinking once the cutout opens it will be FREE flowing so 2.5 might be too much ...

DangerousDan

iTrader: (8)

talk about sleeper. I just put a 3" magnaflow high flow muffler at the axleback section, and the car is super tame now. I am also adding a second 3" muffler inline (round body muffler) to quell the noise, and since I am going turbo plus keeping a high flow cat inline I should be damn near silent.

if you are that concerned I wouldn't install any resonator, but another muffler instead. I am serious when I tell you the 3" muffler is that much quieter than the ebay muffler I had before. the noise comes from the engine bay now, like it should, instead of the muffler

DangerousDan

iTrader: (8)

I mentioned this in my pm to you, but I will post it here for everyone to see!

If your cutout isn't open at all times you aren't losing torque. If it opens ONLY under WOT, and not at a preset point, you should tune it using the size of the piping and cutout. If it opens AFTER a certain RPM and ONLY IF you are at WOT you should tune it on the dyno. You can find the best RPM for it to open for max HP while retaining all your low end torque while it's closed.

remember, this is a variable in your tuning that you can use to make the car that much better. we know that for a NA engine you have to have some backpressure to help create torque, and we also know that backpressure is bad once you get up in the RPM's because the engine is having to work to move the exhaust while you lose HP. If your max torque is at 4k, and then starts to taper off, but your HP is starting to really climb, you can have the valve open at 4k helping your HP since the torque won't build anymore anyway.

there is no certain point that will create more power AND torque, so you have to find the happy medium while on the dyno. Realistically, the best way to tune this would be distance over time, or a 1/4 mile run on the dyno, because you can't be sure which is more important for actually propelling the car forward with a variable such as this. since it affects both HP and TQ at the same time, in what we can assume would be opposite directions (up in HP and down in TQ) there will be a good deal of trial and error to find the correct sweet spot.

my $.02

migueralliart

iTrader: (10)

I really think you are absolutely right about this , the main reason I am going to do this is not the low end torque(it is a bonus), you see the cops in PR see that you have a chrome exhaust tip and they stop you... then start looking at your tint and give you tickets almost for everything , they don't give chances , I agree with speeding tickets(that why I am getting a laser jammer) but exhaust tickets I think they aren't fair ... I mean 150 .00 for just a muffler..... that is nonsense....
I will install the piggy first then the cyl head with the IM then the header with cutout .... and then tune ....
I will try to open the valve @ 4k and WOT and see what happens with the HP peak... with headers I really think there will be a GOOD gain. I was gonna do a full 2.5 exhaust costing me sort of 400 $ now I will only use the cutout retain low end torque and have bigger gains with less noise .... for daily driving

EDIT ; I think I will put a resonator in the cutout exit just to quiet it down a bit.. DAN do you have any thoughts about the cut out 2.25 or 2.5 ? the downpipe is 2.5 and CAT is 2.25 , I believe 2.25 will be more than ok , whats the normally open header diameter in drag?

DangerousDan

iTrader: (8)

yep sounds like you got a plan man, let me know how the tuning of that valve comes out, I am very interested to see where on the tach the biggest gains would be on something like this

MITVRX

^ agree. Everything is spot on!

Backpressure is good for low-end but is not good for top-end - yikes. Thats why 2.5" would be good in that sense.

But with this exhaust, it sounds interesting. In fact, its probably the first time I've encountered it. Sounds good. Like to hear it on low end and WOT. Would it sound vtecish if it opens up at 4k rpm + ?

hee hee

DangerousDan

iTrader: (8)

much much louder than vtech. we are talking about switching from a basically stock system to open headers. super loud.

migueralliart

iTrader: (10)

I am just curious about how the torque band will react , I think that it will be extremely powerful in low end but as it opens there will be a small decline in the torque curve and then will keep rising some more and eventually decrease.... anyway it seems to be the best compromise between both worlds but it needs to be tuned and tested for its best activation point.....

DangerousDan

iTrader: (8)

you are probably right, but I would imagine you will see a point where you can get it pretty stable. Like I said before, keep a safe AFR and see what it does to your TIMES, not your CURVES. With a valve like this you really have to pay attention to what the car is really doing. your HP and TQ are already going to be pretty high, regardless of the valve, so you want to be sure if you need HP or TQ to make it lower your acceleration TIMES. you get what I am saying?

migueralliart

iTrader: (10)

Yes I understand... I don't know if someone has actually done this before I think we are wondering in strange territories here ..... BTW I really like your signature now, helps a lot with the noob's hehehe...

migueralliart

iTrader: (10)

screw the cutout , people we should organize a group buy for this , PLEASE MITVRX GATHER MORE INFO ON THIS THE COMPANY IS IN AUSTRALIA..

Variflow

DangerousDan

iTrader: (8)

that's pretty cool man, and looks exactly like what you need. great find.

KreepaEvoX

What a FAVOR you've done to us, 1000 thanx...Test my exhaust now PIG!!!

DangerousDan

iTrader: (8)

watcha gonna do now sucka!

migueralliart

iTrader: (10)

We just need MITVRX to give em a call sinve they are in AU hes the man in charge !!!! I am waiting for him to go online !!! I belive its a 7hr difference from WA so I will just wait until he goes online

I think this thing is a nice piece of engineering I mean it even has a controller , **** Ferrari variable headers this is better !! your RA with a killer torque curve and always flowing as best as it can. This will even make my tuning even easier.