I just spoke with Vortech and they said they haven't heard of many people doing this but also think the results wouldn't be good. Said the ti blower would probably surge a lot on the S2000 due to the high revving or something since it would be past it's efficiency range.

Only option they said was really available is the si trim which would give me a 15% increase in flow. It would have the same max impeller speed etc. So don't think that would really be a big difference all together.

My stock V2 unit seems to be pretty maxed out running the 3.6" pulley. Only making 14.5 psi I believe but I am also running a 70mm exhaust and test pipe which usually lower the boost a little compared to a 60mm.

3.6" on an AP1 is usually at or above max rpm limit for that blower.

I really want to go for more power but not sure if it is worth it going with the si trim upgrade from Vortech or not. Might give me a 2 psi bump or so I guess.

Who has done the si upgrade on their vortech kit? How were your results?

I am making 422whp right now but also using an AEM meth injection kit. Didn't seem like it did much if anything as my previous tune at 12.5 psi I made 406whp with a 4" pulley though. But meth kit would help if the boost was increased more I bet.

 

I have the Si trim upgrade at 18 psi. Haven't had a chance to dyno. The night before I was going to go, I found a leak in my aftercooler so now BEGI is building me a larger custom upgrade unit. I'm slightly overspinning the blower, but I can tell you it's not blowing hot. My intake temps were no more than 25F over ambient in boost, but take that with a grain of salt. I was trying to get some road datalogs before getting the aftercooler upgrade but the car would spin 275s at the top of 3rd so it was difficult to get accurate road AFs, intake temps.

 

A custom aftercooler? What is the estimated costs and what size core are they trying to use?

 

Nice. What rpm do you rev to? Are you running a larger crank pulley from the 6"? I would think a 6.5" or so would help out a bit get to the higher boost like that. Maybe the si trim would be enough of an upgrade for now. I would think 18 psi would be overspinning it big time no? On the 3.6" pulley making 14.5 (should be around 15.5) I am already over spinning it I believe at 9k rpms.

 

Chitoki,
I'm still waiting on final cost. It's not cheap but I was stuck. There are no more vortech s2k aftercooler made and I couldn't wait around until one popped up used for sale. I'm in a graduate program and my car time has been cut to pretty much zero. It was just easier to pay BEGI to fix my problem. I like Corky. Just tell him the results you want and leave the solution to him. I've forgotten the size of the core, but it's over 50% larger volume IIRC. Cost for the core was somewhere in the 300 range. I still need the endtanks though.

Mod,
I calculated most of this from looking at the SOS E85 guys using the N1200 since it's the same blower. I was originally spinning the blower to 54k, 2k over max at 9k on the motor. I took inspiration from 99SH and increased my crank pulley to 7" so my blower pulley could stay above 4". I used a 4.2" pulley to get me to 18 lbs. When I initially got dyno tuned (and had valve float) my timing was set at 20 degrees up top and not a hint of detonation (meth/water injection). I upgraded to supertech valvtrain and 9500 redline so I should be close to 470-500 whp. You can go as big as 6.75" on the crank without hitting the water pump pulley. I just got a custom water pulley cause I wanted that extra 0.25" AND it's nice slightly over driving the water pump in Southern US heat. Coolant temps are outstanding.

You already have the meth setup. I say go for the blower upgrade and spin it to 18-19 psi!

 

Yeah I think I probably should go for it. Go big and see what happens. I really want upper 400-500whp range. If I keep the S I will be doing a stroker build over the winter most likely which should definitely get me there with some more boost!
I think a 6.5 or 6.75" crank pulley should be more than enough. I don't get any slip now with the 3.6" pulley. So running the larger crank pulley the same 3.6" pulley should get me some good amount of boost. Not sure how to calculate it but I would of course look into it.

What size pulley and stock crank pulley or larger when you were overspinning it by 2k?

 

7" crank pulley and 4.2" blower pulley (may be 4.3"-I forget) spun the blower to 53"-54". Pretty much everyone pushing 18psi or more are over spinning. I had a leak in the after cooler so I may see more now. Since you're keeping the 3.6", you're already at 54k blower rpm with the 6" crank pulley. Soulicious got 19 psi with a 3" blower pulley and 5.45" crank pulley=little under 54k impeller rpm. Double check my math, but this is how I calculated my projected boost. IIRC There may be two more folks boosting this high on the N1200. I don't have the links though. Sorry.

 

So being that I am at 54k already can these really handle more rpm's than that? If I got the si upgrade wouldn't it still be overspinning the same amount regardless? Wouldn't think I could go down to a 3.2" for maybe 18-19 psi and have the blower stay in tact?

 

I run a 1200 maxed out at 52,000rpm. That works out to my redline of 8350rpm and 3.2"/5.45 pulley combo if that helps anyone out. Im on a lower comp motor, but I average 16.5psi in the hotter months and have seen as high as 19psi in winder. No belt slip issues.

 

The concern with overspinning is with the bearings' service life. The blower itself will be fine. Sideways? upgraded his T trim bearings I believe and he's been spinning over 20 psi on a lower comp motor for YEARS IIRC. I haven't seen him post in a while so I'm not sure. As long as your underneath your knock threshold over spin it. All you end up doing is shortening the service interval. How much? That's really dependent on you? I haven't seen to many threads about N1200 bearing rebuilds, but then again, not to many are out in this territory.

HTH