m52b28 inlet manifold VE vs m50 inlet manifold

[Supafly]

I've got a m52b28 which I'm going to be turbocharging with an aim of 350-400bhp.

I've ran one of these N/A with the original and then the m50 inlet manifold which I thought was a good upgrade but I did notice the drop in mid range torque.

I would like to keep as much torque as I can down low while running a larger turbocharger for the top end, will sticking to the original inlet manifold cause a significant restriction >5k rpm and thus lead to increased exhaust back pressure?

Does anyone have data/examples of this?

[ACJJ619]

What exhaust will you be running? That's the main thing that'll effect your back pressure.

[DanThe]

A few millimetres in intake runner size isn't going to make a lot of difference when you have compressed air coming through it

[Supafly]

Thats my thinking too DanThe. I'm not chasing silly power so why not have my cake and eat it too
(even though I think > 300bhp in a light rwd is bordering silly)

I was just wondering if anyone had actually experienced the difference. If you're not going for peak bhp numbers then why not keep the midrange boosting inlet manifold, run a slightly larger hot side and pick up the 5-6.5k rpm with the forced induction?

Acjj619, the exhaust system (turbo to tailpipe) back pressure is not the issue here. If I try to overcome too much intake resistance by increasing boost pressure the turbine back pressure multiplies by > 2 times the intake resistance. This leads to reversion/charge dilution then things take a swift downwards spiral to pre-ignition and unhappy engine components.