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DISCUSSION => Swaps, Turbos, Buildups => Topic started by: 1991 E30 M42 on February 28, 2007, 09:41:45 PM

Title: Bottom mount turbo
Post by: 1991 E30 M42 on February 28, 2007, 09:41:45 PM

Has anyone thought about making a bottom mount turbo? With the A/C compressor removed there is plenty of room and you can send the down pipe straight back in between the sub frame and engine mount bracket.

Title: Bottom mount turbo
Post by: asubimmer on February 28, 2007, 10:20:18 PM

I can either use my manifold as a top or bottom, I'm thinkin about going bottom mount.  I'll decide in the next few days and go from there.

Title: Bottom mount turbo
Post by: BrandC on March 01, 2007, 12:14:36 AM

it's more sleeper bottom mount

Title: Bottom mount turbo
Post by: Shocker on March 01, 2007, 12:23:22 AM

Quote from: BrandC;20346

it's more sleeper bottom mount

But you’re limited to a smaller sized turbo bottom mount.   If you want high boost levels you want a top mount.

Title: Bottom mount turbo
Post by: 1991 E30 M42 on March 01, 2007, 07:04:17 AM

Quote from: Shocker;20347

But you’re limited to a smaller sized turbo bottom mount.   If you want high boost levels you want a top mount.

If you move the turbo further forward and have it sit lower, you can probably fit a bigger turbo with a bottom mount setup because you wont have to deal with the clearance issues that you have up top. Besides, most people that turbo the M42 aren't going to be running high boost levels, so a smaller turbo would be much more efficient at lower boost levels and with the M42 being a 4 cylinder it would spool allot quicker.

Title: Bottom mount turbo
Post by: 2002maniac on March 01, 2007, 07:45:55 PM

Front-bottom mount would make much more sense than rear-bottom mount.  Turbo access and piping would be much easier.

If my car werent my daily driver I'd do a bottom mount SC right there.

Title: Bottom mount turbo
Post by: 1991 E30 M42 on March 01, 2007, 09:32:16 PM

I have thought about doing a supercharger there but ended up not doing it. I have a crank pulley on my m42 that is setup for a flat belt for the A/C and figured that it would be perfect and I was going to have a friend weld up a bracket for it.

Title: Bottom mount turbo
Post by: asubimmer on March 11, 2007, 10:50:36 PM

bottom mount, in the rear, is a no go.  there just isn't enough room.  this manifold deal is a PITA

Title: Bottom mount turbo
Post by: vatos_p on March 12, 2007, 01:08:22 AM

the biggest problem of all , for bottom mount is that if you are not very carefull and cross a water bump , wile your turbo is hot , then the most probable thing is that you will need new turbo , because it will crack... down there , there is no protection from water... and bumps with water is not a rare sight... top mount is safer , and more efficient from alla views..

Title: Bottom mount turbo
Post by: kowalski on March 12, 2007, 02:37:22 AM

you could easily build some sort of shield tho, plus generally water would be spraying in the other direction , and it would be pretty hard to spray there in any large quantities.

Title: Bottom mount turbo
Post by: fabe on March 12, 2007, 04:16:29 AM

I have thot of attempting a bottom mount turbo set up but I have even less space to work with as my car is a RHD. Will think about it once I've run out of things to play with NA...