It has been interesting reading this thread. I recently picked up a turbine for my OBS. I am now considering which compressor wheel to pair with the turbine for optimal performance. In looking at the normal SXE turbos, they seem to run a 7 blade wheel. I am looking at the 7 blade from spturbo. I would post a link, but they are closed for the holidays and have pulled down the website. Why did you choose a 9 over a 7?

I dont plan to change housing, as I think the 1.15 will be fine for my needs, and keep me from fighting EGTs.

Any help down this path would be greatly appreciated

I will explain my choice the best I can. Go back in time a little bit when SX-E was the SX-3. They came with cast wheels before FMW compressors. The cast wheels were almost identical to the cast 7+7 wheels minus some small features. 7+7 is pretty moderate in sound levels and claims to have a good split on low end and top. I was on the fence between the 7+7 and 9+0 as they cost the same. Simple math will tell you the 7+7 has 14 blades total and the 9+0 has 9. Although the 7+7 has different length blades the lower blades are still about 3/4 the total height of the main blades. 9+0 has equal length blades and 5 less blades than the 7+7. 5 less blades is quite a bit of material in regards of weight of the compressor wheel. Have to dig around for some specs but I believe the 9+0 is lightest next to the RR 4+4 billet. The next reason I chose the 9+0 is because of the noise. The stock SD turbo is noted for being a pretty quiet with the stock cast 9+0 wheel. So in similar sequence of how the SX-E kept the same profile wheel as the SX-3, I did the same. Back to the noise factor. The turbo I am running has the ATS ported housing. These housings have Map Enhancement Grooves/ aka bleed off ring around the compressor inlet. Staggered compressor wheels like 5+5, 6+6, 7+7 are often much louder. This is because the lower blades on staggered wheels comes right up to the edge of the bleed off ring. This creates more of a cutting force of the air making more noise. The 9+0 equal length blades come up over the MEG (map enhancement groove) instead of below the edge of it. This eliminates the aggressive cutting force of the blades in relation to the MEG. Resulting in a much quieter turbo. Stock 3" inlet turbo (non ported) does not make the same noise with a 5+5, 6+6, 7+7 as ported housing do. Although they still make more noise than a 9+0 or 11+0. 11+0 is a heavier wheel than the 9+0 but is claimed to be quieter. A lot of BIG turbos, even SX-E come with an 11+0 and a MEG housing. I have ran an S366 with a MEG housing, 6+6 wheel, and it was a pretty loud combination. Personally I like the a more mellow tone instead of a screamer.

Example here, 5+5 and ported housing.

Correct. I looked at the SXE as it seems to a very efficient unit. Then I started looking for wheels that were similar in design, but would work in a stock turbo. That is how I found the 7 blade for the TP38 at spturbo.

Intersting info on what drove you to a 9+0