So I am looking to upgrade the motor in my GSL-SE. I have a series 5 motor I will be streetporting and rebuilding. I am after the higher compression, and higher RPM the series fives have due to thier lighter rotors, however, I really like the awesome low end torque the S3 motor has due to its way heavier rotors.
I am wondering if I could use the GSL-SE (S3) rotors in a 91 NA 13B (S5)? If so would I lose the higher RPM and higher compression the S5 puts out?

I plan on building a Franenstien after this that includes;
Bridgeported 12A plates
GSL-SE housings
S5 or Renesis rotating assembly
All oil mods
hardened internals
Webber 48IDA
and so on..

Please let me know what you think. If you know of anyone who has done this in the past I would be curious to know.

 

This is the first time I heard anyone claim heavier internals gives you better torque...


-Ted

 

I think part of that has to do with the restrictive GSL-SE intake and TB compared to the S5 with its VDI. I drove a car with a Series 4 block and GSL-SE intake though and it didnt seem to have that off the line thrust of the GSL-SE.

 

I could be wrong but arent the S3's 1.2L and the S5's 1.3L?

Wouldn't that mean the housing/rotor are different sizes?

I could be wrong, but I don't think thats going to work...

 

Thier are 2 different series 2 motors, The 13B wich I am refering to , and the 12A, wich is 1.2 and ya totally different. I have been refering to the GSL-SE wich is the model of series 3 that came with the 13B.

 

You can put S3 rotors into an S5 engine, but you would also have to swap counterweight, flywheel, and clutch. Also by doing so, you would be going down in compression ratio a bit.

 

Well, expensive as it is, why not get some brand new RX8 rotors instead, with their redesigned side seal technology ( I swear I watched a video about how the RX8 side seals are different than the FC ones) EVEN lighter weight, and higher compression? IF you have the $$$ then that would be awesome!

 

So would I be down to the GSL-SE compression ratio, or still on the higher side? I know I have to swap the WHOLE rotating assembley.

 

I plan on using RX-8 (Renesis) rotating assembley in my Frankenstein motor build.

 

So has anyone done this? If so what were the results?

 

Yes, you would then be running the GSL-SE compression ratio.