Mods at altitude - BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)

fu2_pal · 03-25-2008, 10:40 AM

I see that some of the the juicebox upgrades are limited to less than 1500 ft of altitude. Why is this?

I live at ~6500 feet and plan to track the car at local tracks and at Miller in SLC, all of which are at least 4500 Ft.

What other considerations for tracking a 135 at altitude?

Ren Finley

john970 · 03-25-2008, 10:53 AM

My guess is the turbo overspeeds at altitude and will probably burst. Higher altitudes make the turbo spin faster to overcome the higher pressure differential and still achieve the listed boost pressure.

The dinan mod lowers the boost pressure on the tiny n54 turbos at high rpm to prevent this, sounds like juicebox doesn't.

I'm not modding my 1er for this reason - we basically get chipped cars up here by virtue of the higher pressure differential we get. We will not see the big 50hp+ gains others are seeing at sea level.

silverbullet135i · 03-25-2008, 11:42 AM

hey lets plan a Miller Race Day!
im in slc, and you guys are in denver...
lets do it!

03-25-2008, 10:40 AM	#1
fu2_pal Registered Drives: Join Date: Mar 2008 Posts: 3 iTrader: (0)	Mods at altitude I see that some of the the juicebox upgrades are limited to less than 1500 ft of altitude. Why is this? I live at ~6500 feet and plan to track the car at local tracks and at Miller in SLC, all of which are at least 4500 Ft. What other considerations for tracking a 135 at altitude? Ren Finley
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03-25-2008, 10:53 AM	#2
john970 1er Drives: 08 135 Join Date: Feb 2008 Location: Denver Posts: 1,200 iTrader: (0)	My guess is the turbo overspeeds at altitude and will probably burst. Higher altitudes make the turbo spin faster to overcome the higher pressure differential and still achieve the listed boost pressure. The dinan mod lowers the boost pressure on the tiny n54 turbos at high rpm to prevent this, sounds like juicebox doesn't. I'm not modding my 1er for this reason - we basically get chipped cars up here by virtue of the higher pressure differential we get. We will not see the big 50hp+ gains others are seeing at sea level.

03-25-2008, 11:42 AM	#3
silverbullet135i Brigadier General Drives: AW E90 335i ///M Sport Join Date: Mar 2008 Location: SL,UT Posts: 4,280 iTrader: (1) Garage List 2010 BMW E90 335i [0.00]	hey lets plan a Miller Race Day! im in slc, and you guys are in denver... lets do it!