chokeasphyxia

iTrader: (8)

godzillar32

I agree but the volume doesnt destroy engines, its the level of boost pressure you run that causes the reliability issues with stock internals (In relation to comp ratio), again, working on the car having no det issues tune-wise..............???

Braineack

iTrader: (62)

still doesn't mean you are educated in the subject matter, because you've proven you aren't.

not a bad thing, but you are wrong on this.

Clos561

iTrader: (3)

this is best comparasion that you might understand.

10 psi t2 turbo(small) vs 10 psi t4(large)

the smaller one will produce less volume at 10psi because of the size. the bigger one will have MORE volume at 10 psi since its larger.

compare it to this.....

a miata traveling 50mph hitting a parked car vs a 20 ton semi truck hitting the parked at 50 mph. both traveling the same speed (producing the same psi) but will give different outputs.

which one will cause more damage? ( produce more volume/horsepower )

godzillar32

OK, can we just get back to the original question...at what BHP level do the stock internals tend to let go at?? The stock compression ratio must be a factor in dictating the level of boost and power the stock internals can take before going bang? That is all I was trying to establish in the first place???

2ndGearRubber

It isn't so much the internals, as it is the transmission and rear end. 5spds are in a danger zone at about 250whp. 6spds have proven to be stronger. 1.6 diffs can be blown up under stock power. I don't remember any recent posts about a blown 1.8 diff.

IMO, most blown motors are results of poor tuning. Detonation is the ultimate killer of motors. If you are running a stock head, valve float is another concern. 250whp has been done frequently with stock internals. And 250whp makes a miata pretty quick.

If I were you, I'd buy a smaller, more responsive turbo, shoot for 200whp, but with a nice wide torque curve. That'll make the car more usable in day-to-day driving than shooting for an arbitrary peak number.

godzillar32

Scott,

Thanks for the really helpful post mate. So im guessing a T28 is the way forward, offering at least 250BHP capability but still giving good spool-up rev's wise. What is the reccomendations for a budget manifold? i was going to buy one of the ebaycast jobs, then port it, skim the manifold flange and put in relief cuts to help stop cracking......or are the fabricated log type SS units any good?

Cheers

Andy

2ndGearRubber

Begi manifolds have been used with some success, although relief cuts are mandatory to prevent cracking over time. Flyin Miata manifolds appear to only be available in T2 sizes.

If I were looking for a manifold, I'd watch the "For Sale" section of the forum (as well as the other major miata forums) for a used one. Someone upgrades to a tubular manifold, ditches their cast manifold on the cheap, you win.


You could always pay a fabricator to build you a custom manifold, but that may abandon your "on a budget" plans.

EDIT: Ebay manifolds may be hit or miss. Are you willing to take the risk of having to buy a replacement manifold? Sometimes it's better to pay for the extra peace of mind. It's all about choices. Sometimes the option with a higher upfront cost will end up being cheaper in the long run.

godzillar32

So are the cast 1.6 turbo manifolds on ebay a load of crap???

2ndGearRubber

That's the thing, I don't know. Ebay sourced car parts are a bit of a gamble. You could buy one that cracks in less than a month, or get one that lasts 5+ years with no problems.

If the car needs to be daily driver reliable, go for the more expensive options, they're proven to work well and last. If it's a toy/weekend car that can afford to have some down time if a part fails, the Ebay manifold seems more reasonable.

It all comes down to time. Ebay parts ARE more risky than their tried and true counterparts. IMO the Ebay sourced part will fail sooner than more expensive/more readily used parts. On the other hand, you can pick up a manifold for what? $125? You could buy a few before you equal the cost of a custom unit. Same thing goes for turbos, you can blow up plenty of chinachargers before your cost equals that of one Garrett. If you can afford to have the miata go down due to a turbo system problem, and have the time/energy to possibly remove/replace parts, pick up an Ebay log and roll with it.

Chinachargers are becoming more and more common (as I'm sure you know). The quality of those Chinese turbos seems to be increasing. Does this mean the manifolds have gotten better? Who knows? Wanna be a guinea pig?

Braineack

iTrader: (62)

250 rwtq.

BHP. lol.

2ndGearRubber

Very true. Torque is what moves the car (and breaks ****); HP is the rate at which said torque is applied.

Braineack

iTrader: (62)

no.

2ndGearRubber

How so?

Braineack

iTrader: (62)

HP is a product.

2ndGearRubber

"Torque, moment or moment of force, is the tendency of a force to rotate an object about an axis"

"Torque is a measure of the turning force on an object such as a bolt or a flywheel"

So, torque is the force that makes the drive wheels of the car rotate, propelling it. How is torque not the force that moves the car?


Horsepower = (Torque X RPM)/5250

Horsepower is a measurement of how torque is applied throughout the rev-range. Thus, it tells us the rate at which torque is applied. Low HP means slow torque output (think Semi truck with a diesel), and high HP means quick torque output.

Faeflora

iTrader: (2)

God damn both of you shut the **** up.

Most boost on a stock block is probably 25-30psi. As for most power, people have run 400hp on the stock block. The stock rods are weak though and will bend and die as early as 250hp though.

godzillar32

Lol....go 2ndGearRubber.............im liking your style!!

Braineack

iTrader: (62)

it appears that HP is a product of a math equation...

godzillar32

FaeFlora....please read my question...Im asking what the max power/boost level is for a stock engine with stock internals that has been boosted? Back to my point......the CR will be the ultimate limiting factor and there is no way on hell a bone stock engine with stock internals will take 25-30Psi......................is there ? lol

Lets all stop scoring points....even someone who isnt a Noob and who is "Experianced" on this forum can get it totally fucked up......and gets taught a lesson (Well done Scott..**** Hot teaching dude!!)