s2000Junky

I ran my 1200 blower/3.2" pulley with the standard Comptech set up 5.45 crank, and aftercooler seeing 17-19psi depending on ambient temps. Ran the stock diverter valve off the old 3/4" aftercooler nipple that used to be for the OEM air injection, and then a simple 25mm pnp Turbo smart BOV at the normal location. Never had belt slip and never had any kinds of issues being reported here with compressor surge. My 2 25mm BOV were also plenty able to evac with no flutter and operated under the standard light 1-3lb opening, to allow max boost at 0 vac throttle for max performance. Vtec set at 3500rpms and comes in at 0 vac/30ish% throttle opening. Rock solid consistency and got all available performance out of the blower. Only thing I can think of why some guys are having these out of the norm issues, is because they have added variables and complications to their set ups, deciding to depart from the standard kit layout which proved so reliable.

s2k manic

its just colder air and a big blower with air to water my iat's where almost double in some instances especially after stopping the car for 20 minutes in 100f weather those high iat's made it a dog now the car is crisp as a cold start.

s2k manic

Here are some pics of my setup . I was able to stop the surge with lowering vtec using cast 90 degree elbows welded to the 3 inch pipe this gave me great flow along with a very efficient intercooler that and dual staggered bov's and poof surge gone i did have to tune it myself and study thermodynamics. like i said cold air + less compressive charge with restriction at the valves = surge

rmerchant3

That setup is actually quite efficient at for that pulley combination. My setup info is all in the OP. It is very similar to yours except I am air to water. I am leaning heavily towards surge.

I had dual bosch units on my old 1220 setup. At 11.2psi max, I would get fluttering if I let out at anything above 7000 rpms. That is why I switched to the Tial. I feel like I have eliminated all of my variables with my different troubleshooting methods with no results. The only thing left is the supercharger. Paxton states it either works (creates boost) or it doesn't.....not very helpful.

s2k manic

when i was air water i had some surge up high and on throttle chop with a godzilla bov and vm 25mm bov and it wasn't enough to keep the novi 1000 happy so i went full retard when i did this setup if i was running your pulleys i would be seeing 20-22 psi at 8500 rpm

rmerchant3

Another interesting mix to throw into the equation. So I introduced a boost leak by removing the plug in the air injection nipple on the aftercooler. The fluttering of boost was reduced, and it still made the same psi at 5000rpms. That goes to show that the blower is producing more air than the engine is able to consume.

s2000Junky

Maybe yes depending on your pulley size choice, but only at 5k rpm and probably not in the way your thinking about it. Our engine flows a lot of cfm at peak rpm, about as much as a standard v8 and any common sized turbo for an s2k application produces significantly more boost at 5k rpm then any supercharger does. The 1200 I think is a perfect match. It produces more power over the 1220 through the entire rpm range given the same pulley size. The 1500 is arguably to big, because its parasitic loss doesn't overcome a 1200 until its over spun to the hilt, and its only seen at peak at much more boost, so from an efficiency standpoint its inferior, and thats how you have to look at sizing a blower to an engine, then comes pulley sizing. I just feel like you guys are treading into complications ive never heard of running this blower until now, the vast majority of us have never had compressor surge issues with it. So that makes me think you have added variables that are creating a problem which isn't the blowers fault. With the standard 5.45 crank pulley and 3.2" blower pulley, the 1200 redlines at 8350 engine rpm. If your math is off or simply ignoring this and over spinning the blower, then expect to have mixed results.

rmerchant3

Maybe yes depending on your pulley size choice, but only at 5k rpm and probably not in the way your thinking about it. Our engine flows a lot of cfm at peak rpm, about as much as a standard v8 and any common sized turbo for an s2k application produces significantly more boost at 5k rpm then any supercharger does. The 1200 I think is a perfect match. It produces more power over the 1220 through the entire rpm range given the same pulley size. The 1500 is arguably to big, because its parasitic loss doesn't overcome a 1200 until its over spun to the hilt, and its only seen at peak at much more boost, so from an efficiency standpoint its inferior, and thats how you have to look at sizing a blower to an engine, then comes pulley sizing. I just feel like you guys are treading into complications ive never heard of running this blower until now, the vast majority of us have never had compressor surge issues with it. So that makes me think you have added variables that are creating a problem which isn't the blowers fault. With the standard 5.45 crank pulley and 3.2" blower pulley, the 1200 redlines at 8350 engine rpm. If your math is off or simply ignoring this and over spinning the blower, then expect to have mixed results.
[/quote]

I know others have had success with this blower, but my setup is not far off from anyone else who has used it. The compressor map shows that the s2000 engine is right on the surge line. I have ran a 3.2 pulley and it still fluctuates. I believe what is overlooked is the amount of CFM that this thing moves. I'm not vast with turbos, but I believe the 1200 has a higher cfm rating at lower psi numbers as compared to a similar sized turbo.

The only great departure I have added is the Tial QRJ, and that should not have affected it unless it was leaking...which after numerous test I have found that it is not. I'm still completely open to ideas.

s2000Junky

Maybe yes depending on your pulley size choice, but only at 5k rpm and probably not in the way your thinking about it. Our engine flows a lot of cfm at peak rpm, about as much as a standard v8 and any common sized turbo for an s2k application produces significantly more boost at 5k rpm then any supercharger does. The 1200 I think is a perfect match. It produces more power over the 1220 through the entire rpm range given the same pulley size. The 1500 is arguably to big, because its parasitic loss doesn't overcome a 1200 until its over spun to the hilt, and its only seen at peak at much more boost, so from an efficiency standpoint its inferior, and thats how you have to look at sizing a blower to an engine, then comes pulley sizing. I just feel like you guys are treading into complications ive never heard of running this blower until now, the vast majority of us have never had compressor surge issues with it. So that makes me think you have added variables that are creating a problem which isn't the blowers fault. With the standard 5.45 crank pulley and 3.2" blower pulley, the 1200 redlines at 8350 engine rpm. If your math is off or simply ignoring this and over spinning the blower, then expect to have mixed results.
[/quote]

I know others have had success with this blower, but my setup is not far off from anyone else who has used it. The compressor map shows that the s2000 engine is right on the surge line. I have ran a 3.2 pulley and it still fluctuates. I believe what is overlooked is the amount of CFM that this thing moves. I'm not vast with turbos, but I believe the 1200 has a higher cfm rating at lower psi numbers as compared to a similar sized turbo.

The only great departure I have added is the Tial QRJ, and that should not have affected it unless it was leaking...which after numerous test I have found that it is not. I'm still completely open to ideas.
[/quote]

The little old NV1000 we ran on our old Comptech kits for the last 10 years was 900cfm. The 1200 upgrade is rated at 1150cfm offered later when the 1220 series came out to replace the NV1000 just for fyi and any turbo cfm cross reference.

I would bet some small cookies that your chosen BOV and spring/adjustment opening/closing timing may not be calibrated appropriately, influencing the symptoms experienced. That is a Turbo BOV which do have different operating parameters over a centrifugal sc valve. I would get your hands on a original Bosch diverter valve, and run that inline and make sure your Tial is timed in sync with the Bosch unit, only then would I feel comfortable moving on to troubleshooting in a different area. You can simply do this by verifying the valves are venting at idle as they are blowing on your hand, and then close at same time when you turn the TB by hand to induce throttle. Making sure the BOV is holding to redline at max boost is important to, but shouldn't influence your problem I wouldn't think, cant do that under the hood anyway.

Another thing to check, make sure air cleaner or related intake piping are not collapsing or creating obstruction under higher pressures.

rmerchant3

Maybe yes depending on your pulley size choice, but only at 5k rpm and probably not in the way your thinking about it. Our engine flows a lot of cfm at peak rpm, about as much as a standard v8 and any common sized turbo for an s2k application produces significantly more boost at 5k rpm then any supercharger does. The 1200 I think is a perfect match. It produces more power over the 1220 through the entire rpm range given the same pulley size. The 1500 is arguably to big, because its parasitic loss doesn't overcome a 1200 until its over spun to the hilt, and its only seen at peak at much more boost, so from an efficiency standpoint its inferior, and thats how you have to look at sizing a blower to an engine, then comes pulley sizing. I just feel like you guys are treading into complications ive never heard of running this blower until now, the vast majority of us have never had compressor surge issues with it. So that makes me think you have added variables that are creating a problem which isn't the blowers fault. With the standard 5.45 crank pulley and 3.2" blower pulley, the 1200 redlines at 8350 engine rpm. If your math is off or simply ignoring this and over spinning the blower, then expect to have mixed results.
[/quote]

I know others have had success with this blower, but my setup is not far off from anyone else who has used it. The compressor map shows that the s2000 engine is right on the surge line. I have ran a 3.2 pulley and it still fluctuates. I believe what is overlooked is the amount of CFM that this thing moves. I'm not vast with turbos, but I believe the 1200 has a higher cfm rating at lower psi numbers as compared to a similar sized turbo.

The only great departure I have added is the Tial QRJ, and that should not have affected it unless it was leaking...which after numerous test I have found that it is not. I'm still completely open to ideas.
[/quote]

The little old NV1000 we ran on our old Comptech kits for the last 10 years was 900cfm. The 1200 upgrade is rated at 1150cfm offered later when the 1220 series came out to replace the NV1000 just for fyi and any turbo cfm cross reference.

I would bet some small cookies that your chosen BOV and spring/adjustment opening/closing timing may not be calibrated appropriately, influencing the symptoms experienced. That is a Turbo BOV which do have different operating parameters over a centrifugal sc valve. I would get your hands on a original Bosch diverter valve, and run that inline and make sure your Tial is timed in sync with the Bosch unit, only then would I feel comfortable moving on to troubleshooting in a different area. You can simply do this by verifying the valves are venting at idle as they are blowing on your hand, and then close at same time when you turn the TB by hand to induce throttle. Making sure the BOV is holding to redline at max boost is important to, but shouldn't influence your problem I wouldn't think, cant do that under the hood anyway.

Another thing to check, make sure air cleaner or related intake piping are not collapsing or creating obstruction under higher pressures.
[/quote]

The QRJ was developed for superchargers. I have the -1.5psi spring in it. Even still, this was my first point of diagnostics. I capped off the Tial and ran my old Bosch off the air injection nipple. I knew this was asking a lot from the Bosch, but it didn't change the fluctuation at all. I then went back to just the Tial and mounted a gopro under the hood to watch the valve while driving. It is completely sealing under full throttle and seems to be venting appropriately according to vacuum/load. My fluctuation in boost occurs at anything above 60% throttle, including WOT.

I have also tried three different air filters. One of them was a shorty style to get rid of the supplied SOS tube. Fluctuations stay the same with any air filter.

This is the video of the QRJ in action. 1:50 and 3:35 are good spots You can actually hear the flutter right before I let off. Especially 3:35.

https://youtu.be/qR4qwNdc4lE