When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Anyone running the 928Motorsports supercharger kit.?
I have bought and installed a second hand 928Motorsports supercharger kit, and I was just wondering if anyone else also has this supercharger kit on their car and what your experiences are.? It seems like after the installation there are more vibrations at idle. I can feel it through the car itself and the steering wheel will vibrate slightly, as I would imagine the car would feel with worn out engine mounts or if something hard is touching the engine. Its just at idle though, and if I just take the revs up to 1000 rpms or above, the vibrations pretty much dissapears.
Other than those low revs vibrations I am pretty happy with the kit. The power comes in nice and progressive and the car feels much more alive now. No noise or supercharger whine at all and temp leves are just the same as before. I have an A/F gauge installed to monitor lambda values, but no boost gauge. According to 928Motorsports it should make 5-6 psi with the standard pulley. Powerwise it feels very much like my old '89 944 Turbo S with M-tune, MBC, bigger injectors and a stage 3 turbo that made a bit over 300 bhp at 1 bar boost, just more progressive and with more power low down before boost.
So if anyone else is running the same supercharger kit I would love to hear your impressions and experiences...
There are some big threads on it. I have that supercharger kit. I could not cure the belt slip until I switched to a double-sided belt and a grooved blower pulley. I do not have an idle vibration problem (or maybe it's very very subtle) so maybe you are seeing some engine mount deterioration or something.
I also had to move the MAF farther away from the blower to solve a problem with CELs (for the MAF) and the car dying if lifting the throttle from a decent RPM while coming to a stop. The system makes great power, tons of midrange. Feels like a V8. The blower whine is a bit distracting on my car (Cabriolet).
My biggest concern for the system is tip-in detonation and I would like to fit an electronic boost control and try to delay the boost for a few microseconds when you hit full throttle. I believe I can feel the tip-in on hot days where I feel a bog and suspect I am getting boost while still in closed-loop cruise. I'd like to fit an electronic recirculation valve and make it dependent on a water injection line pressure signal. That way I cannot get boost until I get water pressure and make that water injection dependent on WOT so I know I am on the WOT timing maps when I get boost. And/or fit some sort of ignition timing management that is boost-aware, or fit a standalone which would be the sensible thing IMO which could run the water injection. The high compression and lack of a boost aware ECU in the 968 coupled with IMO short piston skirts (easier to scuff) make it kinda spooky to run boost on. Great power though.
I haven't had any issues with the kit itself, expcept I had to replace the two rubber gaskets in the FMU unit as they had started to perish. No problem with belt slip or having to move the MAF. It idles and runs just as fine as before, and I have no SC whine or noise what so ever.. I can't even hear its there. I did move the K&N air filter further down so its sitting down behind the left side bumper and not right in front of the air intake slots where its exposed to rain and dirt as well as blocking some of the airflow.
Its only that slight vibration that I would like to get rid off, and first thing is to find out if thats a general thing or just my car. It would make sense if its worn engine mounts, but before the SC installation my car was running very smooth at all rpms with hardly any vibrations, and my car has only done a tad over 70K miles, so that makes me think the vibrations is caused by something else. The vibrations also seems to be less pronounced when the engine is warm and as mentioned, as soon as I increase the revs the vibrations go away. Its not a big issue or really bad, but if its something they can be fixed I would like to do so.. Is there a way to test the condition of the engine mounts with the engine in the car.?
Other then that I am really pleased with the SC kit, and my impression is very similar to Joel's. Very smooth and progressive power with no lag with a big midrange boost. The car just feels eager and ready all the time with power on tap as soon as you touch the throttle.. Its so much fun to drive now and the power on top is quite impressive as well considering its only boosting 5 psi. I don't know if there is a reason to be worried about tip in detonation here in DK, where the weather generally is cooler, and I am also running Shell V-power 99 octane which helps.
Interesting. Can you post some pics of your kit installed?
I can recall some supercharged cars that IMO got scuffed bores, I think one was in the Vancouver Canada area and a 944S2 in the UK so it's not just warm climates. Different SC kits.
I used to have to turn down the boost on my modded Saab 9000 turbo on hot summer days so I have seen how the weather impacts boost sensitivity firsthand.
Here is a pic of how the SC kit looks in my car.. It doesn't really show the location of the K&N filter, but I just extended the 3" tubing so it runs along the bottom inside the front bumper to the left corner behind the fog light, where it sits nice and protected sucking cool fresh air.
My kit did come with the knurled SC pulley, so perhaps thats why I don't have any issues with belt slip.. I am considering upgrading to the stage 2 kit, not so much for the extra power but more for the stand alone engine management and the safety and tuneability that comes with it, But first I'll take my car to a well respected tuning shop nearby for some dyno pulls to see A/F numbers, boost and general performance. So it will be interesting to see if the FMU tip in fuelling can keep up with boost, and if not I will definitely consider upgrading to Stage 2.
Have you had your car on a dyno with the SC installed.? And if so, how did it go.?
I do not see a pic. I tried the knurled pulley but it just ate my belt backing. My car was actually the test mule and I bought it from Carl, belt slip was an issue from day 1 even just driving on the highway, it smelled like a vacuum cleaner and left belt dust on the front of the motor. Carl sent me a couple knurled pulleys but neither worked. Maybe there is a belt that has a different backing that worked with the knurling.
Hmm, thats strange you can't see a pic.. Its there when I look.?!? I don't really know how to fix this when it shows up on my screen but not on others.??
Hmm, thats strange you can't see a pic.. Its there when I look.?!? I don't really know how to fix this when it shows up on my screen but not on others.??
Alex.
This pic. Probably it was too big. I resized it a bit, so it should work now.
Interesting, looks like the recirculation was redesigned to feed back straight towards the blower. That probably cured the CELs from the MAF that I got until I moved my MAF upstream into the nose of the car.
I had also been messing with longer double-sided belts and another pulley to take up the belt when someone in Wales figured out you could take a double sided 7 rib Phaeton V6 (not available in the USA) accessory belt and slice one of the ribs off, then use a grooved pulley on the blower and it all worked out.
I also had to move the MAF farther away from the blower to solve a problem with CELs (for the MAF) and the car dying if lifting the throttle from a decent RPM while coming to a stop.
Hi Joel,
I have the 928Motorsports SC kit as well. I'm believe that I'm experiencing the same issue with the car dying while coming to a stop and have been at a complete loss as to what's causing it.
Please excuse my ignorance but can you elaborate on what CELs is? and would you be able to post a picture of your setup? I'm curious to see how you've re-positioned the MAF.
Sorry I do not check this forum often. CEL = "Check Engine Light", I was getting that light and codes for the MAF. The car would also die if I hit a red light and just let the RPMs drop to idle. I recall it used to have a wavering high idle or something like that also, there are notes on one of the forums somewhere, but that might have been addressed by a redesign of the elbow with the recirculated air return.
I put the MAF down by the air filter and put in a chunk of aluminum J tube from a Honda Civic cold air kit where you have the MAF. There are a lot of intake tubing options that are probably better, I just had this tube laying around from a turbo experiment. The MAF just needs to be far enough away from the blower such that the airflow over the MAF element is more consistent. Those problems went away after the MAF move.
Hey Joel, thanks for the information! I'll look into relocating the MAF. I actually purchased the car with the kit already installed and am in the process of returning it to original spec due to the random cutting out when coming to a stop (caused by the MAF's proximity to the pump). Now that I know what's been causing the issue maybe I won't be in such a rush to remove it
Hey Joel, thanks for the information! I'll look into relocating the MAF. I actually purchased the car with the kit already installed and am in the process of returning it to original spec due to the random cutting out when coming to a stop (caused by the MAF's proximity to the pump). Now that I know what's been causing the issue maybe I won't be in such a rush to remove it
Hi, I know this is an old thread but i'm interested if you did scrap the supercharger kit or if you're having many happy miles of supercharger fun. Thinking about the kit myself for my 968.
They are a rare pick up 2nd hand indeed.
I recently purchased Joel's (jfrahm) unit and am having idle and steady idle return from cruise probs with the turbulence of the return from BOV.
I have only just got the kit fitted up but did have belt alignment issues and had to machine the original pulley on the blower down to get belt alignment.
Its been a bitch and I still haven't been able to drive the car to date. I will play with it again this weekend and try and sort out the issues.
Good luck with your quest.
Peter
04-10-2018, 01:03 PM
Anyone running the 928Motorsports supercharger kit.?
