There are many reasons the E90 Brake Booster belongs in an E30, for the same reason a 24-valve BMW straight six belongs in them. The E9X booster is compact, powerful, abundant and affordable. Because the E9X is a much larger and heavier vehicle, this booster assembly packs a punch. They made over 3 million units of these cars, these boosters are littered in the market, making it a very cheap acquisition. Being from a newer generation, the booster and master design are also superior to the original equipment or other Porsche inspired conversions. Its compact size really frees up critical space in the BMW E30’s engine bay.
Another benefit of running a BMW alternative part is that it bolts right up through the firewall and onto the original pedal-box assembly. You just need a custom pin to match the width of the newly introduced clevis from the E90 part, as it is wider. We sell the Custom E90 Brake Booster Clevis Pin in our store. Now you can clear the intake manifold to a 24-valve BMW engine. *As long as it does not have individual throttle bodies; S54 engines require more clearance in this region and unfortunately the booster needs to be slightly relocated. Half an inch (0.5”) over to the driver’s side plus 1.25” downward is the amount that you will have success with. Results may vary due to some variables, like engine mounts used and tolerance stack-up so make sure you test fit everything to ensure all components are happy and have ample space – however these relocation values have worked for over 100 of our customers.
Brake Master Cylinder:
The outputs on the US E9X master cylinder are inconveniently on the opposite side. Easy solution, grab yourself a euro E9X master - the outputs will point towards the driver’s side. More specifically, from a RHD variant like an English market car. Although, it’s not entirely necessary, if you wish to run the US spec parts you can still make it work. The brake line fittings have effectively been changed from M10x1 thread to M12x1 relative to the original equipment. Keep that in mind when planning out your bubble fittings on your newly created brake lines. It’s also possible to add extensions to your existing lines to get them to reach. The output closer to the driver will go and T-off to meet FL and FR calipers. The other output, towards the nose of the car goes to the rear brakes.
T-Fitting Product Listing - this fitting is not necessary if you are running ABS.
Miscellaneous Parts:
Doing a remote reservoir for the braking system is also another step of the process, a clean mounting solution on the driver side’s strut tower that utilizes a factory thread is in our store: E30 Brake Reservoir Relocation Bracket. It is intended for the 2002 (E10) Brake Reservoir (#34321112399). Alongside some small fittings that are listed in the product description here: Misc. Parts for E90 Brake Booster Conversion
*S54 Specific Information:
The relocation may seem daunting but its pretty straight forward, stick to the guide and it will work out like a breeze. The pedal box bracket will need to be extended on its bottom side to accept the change in position of the holes. We are working on providing a weld-in kit that also provides a jig for the relocation effort.
It is recommended that you weld up the now useless large hole that was previously used by the booster and bellows boot specifically, on both the pedal box bracket and firewall.
Now that the booster is relocated, the attachment point of the booster to the pedal must be relocated as well to compensate. A small steel cylinder can be welded on the brake pedal to suit the new geometry of the E90 booster clevis.
The Blue arrow shows where the E30 booster originally mounted, the Orange arrow shows the newly welded feature that will now connect the E90 booster.
If you are running an S54 engine in your E30, we also provide a Plug-and-Play mounting solution for the OEM Fuel Pressure Regulator:
If you have any questions or concerns, please Contact Me. Thanks for the visit!
-Pasha
www.pasha-parts.com
Another benefit of running a BMW alternative part is that it bolts right up through the firewall and onto the original pedal-box assembly. You just need a custom pin to match the width of the newly introduced clevis from the E90 part, as it is wider. We sell the Custom E90 Brake Booster Clevis Pin in our store. Now you can clear the intake manifold to a 24-valve BMW engine. *As long as it does not have individual throttle bodies; S54 engines require more clearance in this region and unfortunately the booster needs to be slightly relocated. Half an inch (0.5”) over to the driver’s side plus 1.25” downward is the amount that you will have success with. Results may vary due to some variables, like engine mounts used and tolerance stack-up so make sure you test fit everything to ensure all components are happy and have ample space – however these relocation values have worked for over 100 of our customers.
Brake Master Cylinder:
The outputs on the US E9X master cylinder are inconveniently on the opposite side. Easy solution, grab yourself a euro E9X master - the outputs will point towards the driver’s side. More specifically, from a RHD variant like an English market car. Although, it’s not entirely necessary, if you wish to run the US spec parts you can still make it work. The brake line fittings have effectively been changed from M10x1 thread to M12x1 relative to the original equipment. Keep that in mind when planning out your bubble fittings on your newly created brake lines. It’s also possible to add extensions to your existing lines to get them to reach. The output closer to the driver will go and T-off to meet FL and FR calipers. The other output, towards the nose of the car goes to the rear brakes.
T-Fitting Product Listing - this fitting is not necessary if you are running ABS.
Miscellaneous Parts:
Doing a remote reservoir for the braking system is also another step of the process, a clean mounting solution on the driver side’s strut tower that utilizes a factory thread is in our store: E30 Brake Reservoir Relocation Bracket. It is intended for the 2002 (E10) Brake Reservoir (#34321112399). Alongside some small fittings that are listed in the product description here: Misc. Parts for E90 Brake Booster Conversion
*S54 Specific Information:
The relocation may seem daunting but its pretty straight forward, stick to the guide and it will work out like a breeze. The pedal box bracket will need to be extended on its bottom side to accept the change in position of the holes. We are working on providing a weld-in kit that also provides a jig for the relocation effort.
It is recommended that you weld up the now useless large hole that was previously used by the booster and bellows boot specifically, on both the pedal box bracket and firewall.
Now that the booster is relocated, the attachment point of the booster to the pedal must be relocated as well to compensate. A small steel cylinder can be welded on the brake pedal to suit the new geometry of the E90 booster clevis.
The Blue arrow shows where the E30 booster originally mounted, the Orange arrow shows the newly welded feature that will now connect the E90 booster.
If you are running an S54 engine in your E30, we also provide a Plug-and-Play mounting solution for the OEM Fuel Pressure Regulator:
If you have any questions or concerns, please Contact Me. Thanks for the visit!
-Pasha
www.pasha-parts.com