420A Hood exit vs full exhaust

[Inkdlyfe]

So I'm debating on going back to full exhaust, but only if imma really gain from it. I know a N.A. with a cut off exhaust looses alot of power, will I gain power going a 3.5 pipe all the way back ? Or will it not be any difference?

 

[Sjd6795]

Before anyone could give you any sort of answer we kind of need a list of your current mods. But typically if your car is turbo a larger more free flowing exhaust will free up some horse power. However exhaust isn't the only variable in the mix. You also need to be bringing more air into your car as well, the larger exhaust really only gets rid of restrictions from the stock exhaust and allows you to efficiently run larger turbos. If your car is NA no way in hell a 3.5" is going to benefit you in any way. You need back pressure.

 

[Inkdlyfe]

Its fully built nothing is stock really ...
Its a 70mm turbo with anout 2 ft of exhaust 3.5inch the whole way

 

[Sniffbooger]

I'm under the impression that turbos don't really need back pressure....just get it out fast and efficiently as you can...I don't think a full exhaust would improve the power over a hood exhaust. For a turbo engine...but a full exhaust would sound a little quieter!

 

[jed344]

As long as the exhaust is not smaller then the ID of the turbine housing exit there wont be any benefit or draw backs power wise compared to free flowing full exhaust VS hood exit that I have ever seen.

 

[Inkdlyfe]

I'm under the impression that turbos don't really need back pressure....just get it out fast and efficiently as you can...I don't think a full exhaust would improve the power over a hood exhaust. For a turbo engine...but a full exhaust would sound a little quieter!

But I love being obnoxious

 

[Inkdlyfe]

As long as the exhaust is not smaller then the ID of the turbine housing exit there wont be any benefit or draw backs power wise compared to free flowing full exhaust VS hood exit that I have ever seen.

The exducer is 3.5 and my exhast hood dump is exactly the same soze at 3.5 so pretty much I'm just going thought major boost lag

 

[Sniffbooger]

Yeah I hear ya! It's just not right if your exhaust, wastegate and BOV are quiet! I mean, people gotta hear ya coming...and GOING

 

[jed344]

I wish my car was not as loud but wanted full exhaust and free flowing. I have full 3in with zero resonators and just a HKS muffler and it is loud when it comes up on boost. Wastegate isn't that loud now with the MVS 44. The tial 50mm is still loud.

 

[I Y G Josh]

So I'm debating on going back to full exhaust, but only if imma really gain from it. I know a N.A. with a cut off exhaust looses alot of power, will I gain power going a 3.5 pipe all the way back ? Or will it not be any difference?

From what I know of, if the inner diameter on the turbine exit side of the turbo is the same as or lager than the inner diameter of the exhaust system, I believe the only difference to be made by going with a full exhaust is reduced sound but, if you include a muffler on your exhaust system then I believe you may lose some performance due to the added back pressure. Hope this helps. Also, if what I said is inaccurate hopefully someone can correct what I said.

 

[Inkdlyfe]

I mean for the most part over all question has been answered. Idk just feel like I'm lagging hard asf but I guess upping my boost to 28 from 12 lbs of boost is my issue. I gotta say if my BOV isn't loud I know damn sure you hear me spooling loud i just don't have that tuuutuuuu sound and I want that sound . Guess its ether loud obnoxious spool or bov ....

 

[punk3rz]

Going to a full exhaust isn’t going to cause gains. It sounds to me like you don’t know much about the car but if the turbo is as big as you say it is, 12psi is barely enough to spin the turbo so of course it’s going to be laggy. Fully built is a very vague term that’s different from person to person. Update your mod list if you want accurate help. Unless you’re just wanting to quiet down your exhaust, I would stick with what you have.

 

[Inkdlyfe]

I stated on a 70mm im pushing 28 psi just a fyi..
Not 12

 

[punk3rz]

I stated on a 70mm im pushing 28 psi just a fyi..
Not 12

And I’m running an hx35 on 30psi and don’t get full boost til almost 5k. You’re going to have lag with a turbo that big. If you want it to be more responsive, switch to a twin scroll setup or get a smaller turbo.

 

[Inkdlyfe]

I was thinking about putting another one thats smaller to help feed it but then I gotta custom fab a mani and all that I might just deal with this lag just get a giant "boost loading" sticker

 

[JeffGS-T97]

I'm under the impression that turbos don't really need back pressure....just get it out fast and efficiently as you can...I don't think a full exhaust would improve the power over a hood exhaust. For a turbo engine...but a full exhaust would sound a little quieter!

So I'm debating on going back to full exhaust, but only if imma really gain from it. I know a N.A. with a cut off exhaust looses alot of power, will I gain power going a 3.5 pipe all the way back ? Or will it not be any difference?

I've never had a hood exhaust. I'd be very worried about water getting in it while outside. It may not even matter. If I were going to have a short exhaust I would do a side exit just to be safe.

 

[Inkdlyfe]

If parked out side yes that could be a problem. But Its covered where I park

 

[JeffGS-T97]

Then i would go for it. Do you know anyone who has done it? I'm very curious what a 4g63 sounds like with one.

 

[JeffGS-T97]

I just realized you have a 420a w/ turbo sorry for the mistake.

 

[Inkdlyfe]

Its ok but the 420a sounds mean and I'm cammed so its even more aggressive

 

[JeffGS-T97]

I had a 97 burgandy rs 5spd when i was in high school and i loved it! I put a full exhaust short throw long air intake an msd ignition never put a turbo on but i had my eye on the Hahn's Racecraft full set up they had at the time. I think the 420a exhaust sounds better than the 4g63t.

 

[I Y G Josh]

I mean for the most part over all question has been answered. Idk just feel like I'm lagging hard asf but I guess upping my boost to 28 from 12 lbs of boost is my issue. I gotta say if my BOV isn't loud I know damn sure you hear me spooling loud i just don't have that tuuutuuuu sound and I want that sound . Guess its ether loud obnoxious spool or bov ....

Are you referring to compressor surge/turbo flutter, because if you are I know you can achieve that TUTUTUTU sound (depending on the turbo) by not running a bov at all or by trying to increase the spring force on the piston in your bov. Although, by doing this you put a lot of stress on turbo bearings (especially on a journal bearing turbo) and the compressor wheel. I have read that you can cut the life of a turbo in half when doing this.

 

[Inkdlyfe]

Are you referring to compressor surge/turbo flutter, because if you are I know you can achieve that TUTUTUTU sound (depending on the turbo) by not running a bov at all or by trying to increase the spring force on the piston in your bov. Although, by doing this you put a lot of stress on turbo bearings (especially on a journal bearing turbo) and the compressor wheel. I have read that you can cut the life of a turbo in half when doing this.

I run cheap ebay turbos for the most part only about 160$ each so it wouldn't be much of a issue on damaging aspect I just wanna have that more aggressive sound when I left off the pedal

 

[I Y G Josh]

I run cheap ebay turbos for the most part only about 160$ each so it wouldn't be much of a issue on damaging aspect I just wanna have that more aggressive sound when I left off the pedal

Oh okay, then boost at your own risk .

 

[Inkdlyfe]

So I've been running a hood dump directly off the turbo for a good while now but now thinking about changing it up. Getting too hot to not be able to have both windows down. Having a hood dump the pass window gotta stay up sadly unless u like the smell of exhaust.. I was also thinking about just doing a lower front bumper exit but figured it would just do the same exact thing.. Besides the obvious about the fumes is there like a gain so to say from a full exhaust then a hood exit ? Been so long since I had a full exhaust I don't member how it's like ..