Ok i just wanna know if using an s5 tubo on an s4 motor is better....would you feel a difference in power....easy upgrade maybe? cheap maybe? maybe you have went over this before but i have searched..so please dont flame.. what would i need besides turbo and manifold...thanks

 

Quote from BNRTURBOS.com please read:

BNR Supercars specializes in perfecting a flawed design of the 87-88 Turbo II turbocharger. Although the rotating assemblies are the same for all the 87-91 turbochargers, there is a big difference in the turbine housings on each of the turbochargers. The 87-88 (series 4) differs from the 89-91 (Series 5) in just a few ways. The biggest difference is the turbine housing (exhaust housing). The S4 turbine housing has a very inefficient internal wastegate design. This is why most every S4 car owner changes over to a series 5 turbo and manifold. The manifold design for the internal wastegate on the S5 was improved for better boost control, thus helping eliminate boost spike.

The internal wastegate port on a stock S4 turbocharger is a puny 12 mm in diameter. Comparing the S4 to the S5, there is no comparison. The dual wastegate port on the S5 has 2 holes that are both considerably larger than the S4, therefore making it the elite housing to have with a hybrid upgrade. But now things have changed. BNR has designed a custom internal wastegate set up for the S4 that will out perform the S5 wastegate any day of the week.

 

but would it be better for me any hp gains from this??...i just got my hands on an s5 turbo for free..so i wanted to know if i should go ahead and put it on the car...

 

stock S4 turbo < stock S5 turbo

its a good upgrade, but you need the manifold too. Also, i think the oil feed/return and coolant lines to the turbo need to be changed also. Also, you can usually sell your S4 turbo on ebay and then get an S5 one for about the same price.

 

Yes if we are talking stock to stock it is better i terms of the wastegate as bnr states.

 

The compressor sections are identical, therefore, their potential power output is equal.
NO THERE ARE NO POWER GAINS FROM CHANGING OVER.

And if you haven't figured it out yet, YOU CANNOT SWAP THE TURBOS OVER UNLESS YOU HAVE THE PROPER TURBO EXHAUST MANIFOLD.
So, you're free S5 turbo is basically useless for your S4 car unless you get the S5 turbo exhaust manifold.


-Ted

 

YAY Ted!! can count on 20,000 posts of other peoples information but in a more ******* type of way.

 

The manifold is very easy to come by and there is one on ebay right now, or you can usually get one from mrmazda7 on ebay and mazdarecycling.com oh and this forum!

 

i said before that i know i needed the manifold...so i have figured that out..(CAPS LOCKS) lol...thanks..but i guess i wont be using the turbo being that there are no real gains..