is it normal? fmic question

[Jimbo]

Fitted my front.mount setup this morning no problems all went together nicely, drove it fine no boost pipes blowing off etc goes well still maybe feels slightly better than it did, but I'm down on boost pressure only like maybe 2psi it's certainly no slower is it normal to drop slightly due to the longer route?
Any help appreciated
James

[declantg]

surely its bound to be down on pressure as its got further to go?

[Jimbo]

.That's what I though but the wastegate shouldn't open until it produces the set pressure which hasn't changed
I can't imagine there's any boost leaks as it's going really well

[cwspellowe]

Boost pressure will drop slightly as charge temps decrease (air is denser when cold) and the total volume of the system is much bigger than the TMIC system.

Seems normal to me sir. It's not all about absolute boost pressure. 24psi of air at 10degrees C will be a lot more combustible than 26psi of air at 40degrees C. No i haven't done the maths, but you get my drift.

---

.That's what I though but the wastegate shouldn't open until it produces the set pressure which hasn't changed
I can't imagine there's any boost leaks as it's going really well

Yes but as in my above post, the turbo may not be producing enough flow to build up the boost you had before. It's not pressurising a static chamber of air, the engine is eating up that air at the same time.

[Jimbo]

Boost pressure will drop slightly as charge temps decrease (air is denser when cold) and the total volume of the system is much bigger than the TMIC system.

Seems normal to me sir. It's not all about absolute boost pressure. 24psi of air at 10degrees C will be a lot more combustible than 26psi of air at 40degrees C. No i haven't done the maths, but you get my drift.

---

.That's what I though but the wastegate shouldn't open until it produces the set pressure which hasn't changed
I can't imagine there's any boost leaks as it's going really well

Yes but as in my above post, the turbo may not be producing enough flow to build up the boost you had before. It's not pressurising a static chamber of air, the engine is eating up that air at the same time.

Ok buddy what u said makes sense, I should probably up the pressure a bit then.

[cwspellowe]

lolfail

[Jimbo]

Remember your wastegate works on exhaust manifold pressure, not inlet manifold pressure, which wouldn't have changed. It just relates to how fast the turbine spins, which spins the compressor a set amount. This creates a set level of flow, which will build less pressure in a larger, colder intercooler system, while flowing the same amount of air, if that makes sense?

Think I got it, basically the wastegate is releasing at the same pressure, it's the inlet side where the pressure has dropped slightly due to being larger and denser

[cwspellowe]

lolfail

[darrenjlobb]

Remember your wastegate works on exhaust manifold pressure, not inlet manifold pressure,

Waattt????

[cwspellowe]

Remember your wastegate works on exhaust manifold pressure, not inlet manifold pressure,

Waattt????

LOL EPIC FAIL!

I blame working on a bank holiday

I shall sneakily edit everything i just said

[Jarrus]

was going to say as well....