[kern417]

A proper big turbo kit will always be better than hybrids. I just wish I saw them offered with Garret or BW turbos.

[neonnblack]

Doc race is working on a full upgrade. Top mount at that i believe.

[Cpatel]

Do you guys upgrade turbos without changing internals?

If not, do you guys not worry about bent rods or blowing a piston into orbit?

[kern417]

Originally Posted by Cpatel

Do you guys upgrade turbos without changing internals?

If not, do you guys not worry about bent rods or blowing a piston into orbit?

Yes

No

[E90ROXS]

Originally Posted by Cpatel

Do you guys upgrade turbos without changing internals?

If not, do you guys not worry about bent rods or blowing a piston into orbit?

I think it's safe to keep it at mid 500 with OEM internal parts. Tranny starts slipping at 800.

[Cpatel]

Originally Posted by E90ROXS

I think it's safe to keep it at mid 500 with OEM internal parts. Tranny starts slipping at 800.

Originally Posted by kern417

Yes

No

Do you guys limit boost to 21PSI?

[kern417]

Originally Posted by Cpatel

Do you guys limit boost to 21PSI?

Why is this a question? What are you trying to ask? Boost pressure isn't the only thing that determines horsepower/torque. Why pick 21 psi?

[Nugget]

He might think it's like N54/N55s where the stock MAP sensor is only 2.5bar (so 21.7 psi of boost).

What does the B58 MAP sensor read up to?

[Cpatel]

Originally Posted by kern417

Why is this a question? What are you trying to ask? Boost pressure isn't the only thing that determines horsepower/torque. Why pick 21 psi?

I've read around that for the N26/N20, people with tunes or piggybacks, usually mention that 21PSI is the boost limit that they run otherwise engine problems could happen (bending rods and cracking pistons) with higher boost limits on stock internals. I assumed it translated to upgraded turbos.

[kern417]

Originally Posted by Cpatel

I've read around that for the N26/N20, people with tunes or piggybacks, usually mention that 21PSI is the boost limit that they run otherwise engine problems could happen (bending rods and cracking pistons) with higher boost limits on stock internals. I assumed it translated to upgraded turbos.

Ah gotcha. I wondered why people always talk about 21psi. Like Nugget mentioned, it's probably brought up as a limit because that's the limit that the OEM sensors can control. Realistically, a bigger turbo will make the same power at less boost pressure. So 21psi on stock turbo would make the same as 16/17 on a pure turbo, or 14-15 on an actual big turbo like Big Boost's kit. But keep in mind that there are other factors that affect power and torque, not just boost pressure.

I haven't seen anyone run over 22psi. I think it makes sense since there's no reason to give us a 3bar sensor when stock boost is only 10-14psi on B58s.

[OzBMR]

N54 stock sensors are 1.5 bar = 21.7 PSI

B58 stock sensors are 2.5 bar = 36.2 PSI

Edit: B58 stock TMAP sensor is part number 13-62-7-804-742 is combined pressure and IAT with a 4 bar/400 kPa/58 PSI

[kern417]

Originally Posted by OzBMR

N54 stock sensors are 1.5 bar = 21.7 PSI

B58 stock sensors are 2.5 bar = 36.2 PSI

The 2.5 bar value includes ambient. So it always measures 1 bar, and then you can measure 1.5 bar on top from forced induction pressure.

[Cpatel]

Ok so what I'm getting is that if I get a upgraded turbo while running stage 2, I'll be safe as long as I keep HP around or below 350?
If I'm using BM3, I'll need to get a custom tune and ask the tuner to keep the HP at that threshold? I've only used OTS maps so I have no idea how custom maps work.

[kern417]

Originally Posted by Cpatel

Ok so what I'm getting is that if I get a upgraded turbo while running stage 2, I'll be safe as long as I keep HP around or below 350?
If I'm using BM3, I'll need to get a custom tune and ask the tuner to keep the HP at that threshold? I've only used OTS maps so I have no idea how custom maps work.

Not sure about the N26. This is a B58 thread the limits are probably different. Check the N20/N26 forums for more reliable feedback.

[OzBMR]

Originally Posted by kern417

The 2.5 bar value includes ambient. So it always measures 1 bar, and then you can measure 1.5 bar on top from forced induction pressure.

Corrected error in above post. B48 and B58 stock TMAP sensor part number is 13-62-7-804-742 reads up to 4 bar and is combined IAT sensor

[Nugget]

Good info. I assumed the B58 must have more than a 2.5bar sensor as I have seen it show over 22psi (MP tune).

[enemigo13]

yes and in the intake manifold MAP sensor is 2.55bar absolute, same like in S55. But S55 works good with this combination (3.5bar sensor before throttle and 2.5bar after) until ~1.9bar then interesting things begin to happen, so in B58 case no need to change any sensors, as ~1.5 bar should be enough with upgraded turbo.

Originally Posted by Nugget

Good info. I assumed the B58 must have more than a 2.5bar sensor as I have seen it show over 22psi (MP tune).

[kern417]

Originally Posted by enemigo13

yes and in the intake manifold MAP sensor is 2.55bar absolute, same like in S55. But S55 works good with this combination (3.5bar sensor before throttle and 2.5bar after) until ~1.9bar then interesting things begin to happen, so in B58 case no need to change any sensors, as ~1.5 bar should be enough with upgraded turbo.

I don't understand why we have 2. I'm assuming the pre-throttle controls the wastegate and the manifold controls fueling/timing?

[enemigo13]

it's always good to know what actual pressure you have after throttle in the intake manifold. N54 used some formulas to calculate air in the intake manifold from boost pressure before throttle and throttle position, but it's always better to know actual than calculate.

Originally Posted by kern417

I don't understand why we have 2. I'm assuming the pre-throttle controls the wastegate and the manifold controls fueling/timing?

[kern417]

Originally Posted by enemigo13

it's always good to know what actual pressure you have after throttle in the intake manifold. N54 used some formulas to calculate air in the intake manifold from boost pressure before throttle and throttle position, but it's always better to know actual than calculate.

I had the same issue in my VW. They actually moved the sensor to the manifold for that reason on the next generation of the engine. But I'm struggling with the pre-throttle sensor, except that it may be needed when an electronic wastegate is used. That part I'm not familiar with. I'm used to a separate boost controller/solenoid that's plumbed to the wastegate. I'm probably answering my own question.

[enlimalima]

So seems like I'm reading mixed reviews of Pure Turbos here. Keen on getting a Pure St 2 but I saw some experienced broken/bent turbo blades with Pure St 2, and this reliability issue worries me despite the customer support cos I live outside the US and claiming warranty et al might not be easy for me...

Any take on Vargas or Steam? Also I heard Big Boost is making turbos that are on par with Pure St 2 if you dont wish to go beyond 600whp like me...I drive an N55 and not keen on upgrading internals, so a power figure of 500whp is perfect for me...

[Solid67]

Does anyone know anything about the TTE580?

https://tteglobal.co.uk/bmw/6-series...E10321.1&c=416