Confused about next mod!

[SpeedKnight]

So i recently installed new intake. Really smooths out accelleration at higher RPMs and keeps pulling a little closer to redline than before. And digging sound!

On to the next mod. The way I see it from reading these threads is:

1. Downpipe
2. Turboinlet
3. Cobb AP

Now the confusion is first, what order? Second, a few folks have mentioned that a downpipe is a waste if you don't redo the whole exhaust ie. race pipe and subtract cat/s? From reading manufacturers of DPs they say the restriction is in the tight bend of stock DP rather than the exhaust. Third, again a few folks have mentioned intakes are a waste if you don't do turbo inlet also? Most of the reviews on intakes, Roadandtracks of Mazdas CAI and K&Ns got 25-27 gain without turbo inlet. Does the turbo inlet make that much more of a difference? Any one dyno with intake - inlet, then intake + inlet to see the diff?

 

[MSMS3]

Congratulations. You are doing your homework. I can see you have been checking out the threads with a pretty sharp eye.

Your intake was a great mod, and yes, you get great gains without the turbo inlet pipe. The numbers you quote may be a bit high. Expect more like 20 hp and 20 pounds of torque. But this is a serious gain.

You do need to address the exhaust side now. But before you do anything more, you need to be able to monitor what you are doing to keep your engine safe. So, your next mod should be some type of engine monitoring device, at least a good boost gauge. It will tell you if you are getting boost creep or boost spike (latter pretty harmless within limits, former very dangerous if above stock levels on this engine, IMHO). Next stage up from the boost gauge would be a Dash Hawk, or the AP which has a lot of monitoring functions.

Once you are monitoring boost pressure with something, then you can go with exhaust mods. You have already learned that the restrictions are upstream of the CBE, so no need to change that unless you just want to spend a lot of money to change the sound of your exhaust.

You need to decide if you want to stay emissions legal and whether you need to pass testing in your state. That will dictate whether you can save some money and pick up a little more power by going catless, or whether you need a catted DP. Either way you get great gains in combination with your new intake.

The downpipe may produce some boost creep that could trigger your ECU's boost cut or fuel cut. That's o.k. by me, as this is there to safe the engine. Fuel cut is abrupt when it happens. Some tunes raise the level of the boost cut and the level of fuel cut. That's a decision you will have to make. I'm not prepared to give up the safety features just to try build a little more hp on a small turbo.

If you want a more modest but still real gain on the exhaust side, just get a race pipe to replace the second cat section of your exhaust and keep the stock DP for the time being. You'll still have the first cat, and if done right you'll pass tests.

Some would say to replace your stock BPV with an aftermarket one. BPV's or BOV's do not produce any power gains, unless your stock unit is leaking. That's another reason to have a boost gauge or other monitoring system. If you are holding boost at nice stock levels up to 5,500-6,000 rpm on the stock unit, no reason to spend the money on a BPV.

Others will certainly have other ideas of where to go with your mods. This is just my view of what makes sense to me.

 

[SpeedKnight]

Thanks MSMS3. Great stuff. So boost gauge and Dashhawk or Cobbs AP, then DP.

I was wanting to keep stock sound. MS3 sounds great for a 4cylinder, nice deep growl as apposed to the filling rattling screech some tuners have. To each their own I guess.

I have been leaning towards Cobbs DP. Comes with a highflow first cat I believe. Any thoughts out there as to which brand is better? Why?

 

[ncspeed21]

Thanks MSMS3. Great stuff. So boost gauge and Dashhawk or Cobbs AP, then DP.

I was wanting to keep stock sound. MS3 sounds great for a 4cylinder, nice deep growl as apposed to the filling rattling screech some tuners have. To each their own I guess.

I have been leaning towards Cobbs DP. Comes with a highflow first cat I believe. Any thoughts out there as to which brand is better? Why?

If you like the exhaust note now, you will love it with the Dp on!!
i heard nothing but good stuff about cobbs and cp-e's, but i went with a cp-e with a cat!! cant complain either. the sound is much more deeper and still has that growl!! loooovee it

 

[coyfish]

I would start simpler than work your way up. Just how I see it though. No mod is a waste. Each serves a purpose. Inlet will free up a few more horses but not as much as an intake alone.


The inlet doesn't matter but I would get the tune before you get the downpipe. With a DP you might get some scary boost spikes that a tune might help alleviate. Not to mention the AP can measure boost if you don't already have a gauge.

 

[CWPspeed3]

I thought the turbo inlet made a nice change. It totally changes the sound of the intake & bpv though. I do think the stock plastic bpv's will all leak, its not much but after I got my dashhawk I could see it was peaking 15psi and would bleed off to 11psi rather quickly, the forge peaks to 18psi and holds 14-15psi. Before going all power mods I'd suggest a rear motor mount and shifter bushings if not a short shifter as well. Sounds like you've got a good idea where you want to go with the car, good luck.

 

[8.5MS3]

from what ive seen the turbo inlet doesnt improve power much at all. if anything, i spool maybe 100rpm earlier, but again its not a power mod, just allows air to flow more freely into the turbo.

I would definetly get the ap before you start modding the exhaust.

As others have said get a rear mount before you start modding. cpe or SU are both good choices. Shifter bushings and a lighter shifter weight will help as well.