16t compressor wheel to 18t compressor wheel?

Bondo1 · Post by **Bondo1** » 01 Jun 2012, 19:34

Is it possible to change the 16t compressor wheel to a 18t compressor wheel without having to modify the 16t compressor housing ? I recently acquired a 16t turbo of an s70. I have the rebuild kit ordered and want to know if I can just upgrade the wheel while I have it apart?

rapollon · Post by **rapollon** » 03 Jun 2012, 13:11

Thread Jacking Part2: Will this upgrade now make the 16t an 18t?

Post by **jtp** » 04 Jun 2012, 08:11

My guess would be that spool time would be increased since you have less air being pushed around with the smaller wheel, so it wouldn't really be an 18t but would still be "better"/more boost than the 16t wheel in the 16t compressor housing.

Probably depends on how much boost you want to run, I would ask your tuner what they think. If you don't have a tuner be careful about changing the mechanisms that effect boost pressure without a corresponding tune, don't want to destroy your engine internals.

Bondo1 · Post by **Bondo1** » 09 Jun 2012, 17:22

Update.....Rebuilt the CHRA .. Not to hard. Bad news. The 18t wheel does not fit inside the 16t housing. It will fit if you bore out the housing a bit. That's what I'm gonna do. I will update once I finish and try to post pics...... Although I'm horrible with a computer. I was told on this site that the 18t would fit. Soooo ....lesson learned. Don't believe everything you hear on here. Just man up and try it.

Bondo1 · Post by **Bondo1** » 20 Jun 2012, 20:54

Update: bored out the compressor housing to fit the bigger 18t wheel. Very time consuming and requires some patience. It took me two days to get it just right with the 2mm gap between the housing and the wheel. I used a die grinder and some sanding paddles.

After I took out the 15g out of my car I found that it had a lot of shaft play and was definitely ready to be replaced. So I installed the 18t with no problems and it started fine. What a relief! When I went to take it for a drive to make sure everything was working right I noticed I was only boosting to around 8-9 psi with my boost controller turned all the way up. Needless to say I was not happy and headed back to the garage.

After checking for leaks(coolant/oil) and finding none I moved on to troubleshoot the boost problem. Low and behold I had found that I missed putting the cbv hose back on the nipple. I love simple fixes. Slapped it back on and took it for another test drive. Whoa!!!!!! Holy $&@? I was boosting really hard, around 19-20 on my boost gauge. Which is weird because I thought there was a fuel cutoff at 15.5? I had no fuel cut, although I let off early when I saw the boost get that high. So I adjusted my mbc to a reasonable 13-14. It boosts right to 14 and holds it to redline with no boost fade. My other turbo was getting boost fade bad because of a cracked and deteriorating cbv diaphragm. I love it. All in all this turbo cost me $155. A $65 junkyard 16t out of an s70 a $55 eBay rebuild kit and a $35 18t compressor wheel. Oh and you can't forget the your time, but for me I love wrenching on my car so that's fine with me. I need to get a tune so I can use the turbo to it's potential but right now it's a nice upgrade. I did notice a little more lag off the line but nothing to noticeable. Now to rebuild my old turbo, see some mpg figures and see what I run at the strip now!

I will update when I get some numbers.

Post by **boosted5cyl** » 03 May 2013, 10:49

Did you attempt to balance the 18t wheel on the assembly at all?

Post by **Auburn T5** » 03 May 2013, 12:45

I know this thread is old but it popped up on the front page and I figured I would post that Lucky is selling modified 18T and 19T compressor wheels that (I think) are slightly smaller diameter so no grinding of the housing is needed. Just need the

http://www.ardideas.com/Billet-compress ... c_115.html