Built vs. BT

Forged internals first or big snail first?

  • Total voters
    5
Slow6_pl

Slow6_pl

Greenie N00B Member
Allow me paint a picture in your mind. You have this Mazdaspeed 6 that's you've made what it is today. It's your daily, but you like to get a bit rowdy every now and again for shits and giggles. You get all your bolt ons, tuned, misc. items, etc. You save up about $2-$3k. What do you do with it?

My question is, at this point, would it be more worthwhile to buy a turbo kits and supporting components on a stock block, or forge the engine and save for later turbo endeavors? Looking for pros/cons, as well as discussion for one or the other, as I definitely don't have $2-$3k right now. Turbo/build options are appreciated, though I do have a good idea of what all is needed and which turbo I'd like.
 
First off I would have been really thankful if my built engine was only 2-3k! A built engine will more than likely be around the 5k range from my little bit of experience.


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OCD said:
First off I would have been really thankful if my built engine was only 2-3k! A built engine will more than likely be around the 5k range from my little bit of experience.


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In that case, forget the money figures. Essentially, which should come first in your opinion?
 
Im currently going BT first but only because I've got low mileage and fairly healthy motor. Figured i could spend money on a good flowing setup with a good tune on stock block and crack 350. Get used to the power and save for a rebuild/aux fuelling knowing Ive given myself headroom with the current turbo (5858). Should i feel the need for more power once built, its just an easy turbo swap and retune away!


Tapatorque steering
 
TRBLSM said:
Im currently going BT first but only because I've got low mileage and fairly healthy motor. Figured i could spend money on a good flowing setup with a good tune on stock block and crack 350. Get used to the power and save for a rebuild/aux fuelling knowing Ive given myself headroom with the current turbo (5858). Should i feel the need for more power once built, its just an easy turbo swap and retune away!


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That makes good sense. On my end of the spectrum, I have a 10 year old motor with 118k on it. Not sure of turbo replacement prior to my ownership, so it's almost a question of which will give first, and which will I save first!
 
I would go BT first depending on how Big your BT is, but have a compression and leakdown test done.

PS. This thread feels like dungeons and dragons.
 
Big SC said:
I would go BT first depending on how Big your BT is, but have a compression and leakdown test done.

PS. This thread feels like dungeons and dragons.
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I'm the dungeon master, you didn't know? :wink: as far as turbo choice, I am in a constant circle. My choices have varied from a GTX28 to GTX30 to HTA30 to Corksport to S4 to 5558 to EFR kit. I'm a mess man.
 
Slow6_pl said:
I'm the dungeon master, you didn't know? :wink: as far as turbo choice, I am in a constant circle. My choices have varied from a GTX28 to GTX30 to HTA30 to Corksport to S4 to 5558 to EFR kit. I'm a mess man.
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The CS/S4 kit would come almost everything you need to install it.

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Engine health/current power level you're running at would be the deciding combination for me. Is your VVT done? (didn't see it mentioned, but may have missed it)
 
Redline said:
Engine health/current power level you're running at would be the deciding combination for me. Is your VVT done? (didn't see it mentioned, but may have missed it)
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VVT done at about 108k miles. So practically brand new. I'm fully bol tr ed with a shitty OTS tune right now, so with a good tune maybe around 300hp/320tq ish. Haven't cleaned intake valves or done a compression test.
 
Slow6_pl said:
VVT done at about 108k miles. So practically brand new. I'm fully bol tr ed with a shitty OTS tune right now, so with a good tune maybe around 300hp/320tq ish. Haven't cleaned intake valves or done a compression test.
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Clean valves and do a compression/leakdown. Then, if things are good, go BT and stay ~350-360awhp as long as you can. Should be pretty reliable at that level for a long time. I've seen lots of folks go BT at >100k miles with no issues. Just get a good tune.
 
Redline said:
Clean valves and do a compression/leakdown. Then, if things are good, go BT and stay ~350-360awhp as long as you can. Should be pretty reliable at that level for a long time. I've seen lots of folks go BT at >100k miles with no issues. Just get a good tune.
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Thanks for the input! I have a new clutch and flywheel just waiting for my current ones to go, but obviously the motor is of bigger concern.
 
I would take care of the motor first.
So at least there is no unexpected surprise, 10 miles, 100 miles, 1000 miles, etc... down the road, then your left scrapping money and taking short cuts on a new/used engine or built engine.


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cshunter said:
I would take care of the motor first.
So at least there is no unexpected surprise, 10 miles, 100 miles, 1000 miles, etc... down the road, then your left scrapping money and taking short cuts on a new/used engine or built engine.


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Very valid points, can you see why I'm torn?
 
Not to play devil's advocate, but folks have gone BT at 100k+ and tuned for the 350-375whp range, staying there to 200k or so without catastrophic failure. Gotta pay to play, for sure, but these motors are stout and known to go many miles when properly tuned.

It's really mostly conjecture until you have some empirical data; compression, leakdown, etc. If you're super paranoid, you could even pull the oil pan to get eyes on the rods and ensure they're still full-hetero.
 
Slow6_pl said:
Very valid points, can you see why I'm torn?
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I do.

I was debating this at one point in time. Though it did help I wasn't 100% sure on which turbo and setup I wanted.
I did know I wanted at a 3067/76, 5858, or larger.


Though since you're unsure I'd do what redline mentioned, do a compression and leakdown test.

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I blew my stock motor on a k04.....so did both at the same time.....talk about an adventure!
[doublepost=1460475421][/doublepost]I blew my stock motor on a k04.....so did both at the same time.....talk about an adventure!
 
I have just a few minor fix ups to take care of, then I'll have the tests done. Have to know what my penny jar is going to go towards!

Now, excuse me while I strangle myself at the thought of cleaning my intake valves.
 
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