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.
Hello folks.
Because some have asked I decided to provide a part list of items I used to create a custom supercharger upgrade for my GS400.
I will add/edit more parts as I look through my notes and try to provide pics as well.
Vortech V2 S Trim centrifugal supercharger with added 90 degree elbow
T-6061 aluminum supercharger bracket (hand made)
T-6061 aluminum supercharger tensioner bracket (hand made)
928 Motorsports 2.87 supercharger pulley
Mishimoto front mounted intercooler
T-6061 3 inch diameter aluminum supercharger/intercooler piping
Denso (Mazda RX7) 440cc Injectors
2 OEM GS400 (double stacked) power steering pulleys
Reconfigured Ford Ranger air intake tube
K&N intake filter RP-5105 (Camaro/Firebird) Thermostat housing adapter (hand made)
RKX aluminum diverter valve
928 Motorsports mega boost limiter valve.
1 Metric socket cap screw, Class 12.9 steel black oxide finish, 10mm x 1.25mm x 120mm
Performance Motor Research MAP-ECU3 Piggyback
Handmade ECU Jumper harness (No cut up stock ECU wiring)
PLX Devices Wideband Multi-Display
Good parts list! I would however opt for a custom double-stacked oversized crank pulley and run the SC off that instead of off the steering pump pulley. You should be able to get more power per PSI out of your unit due to the ratio change of pulleys using the oversized crank pulley. That’s what I have on my SRT stage 3 setup.
I would also use a Gates freighliner/green strip HD belt. I know, it’s green and a bit ugly but works really well against belt stretching and belt slip on the SC.
Good parts list! I would however opt for a custom double-stacked oversized crank pulley and run the SC off that instead of off the steering pump pulley. You should be able to get more power per PSI out of your unit due to the ratio change of pulleys using the oversized crank pulley. That’s what I have on my SRT stage 3 setup.
I would also use a Gates freighliner/green strip HD belt. I know, it’s green and a bit ugly but works really well against belt stretching and belt slip on the SC.
Kool, but parts list is not finished. I'm posting parts I used as I go allong switching everything over to a different engine.
Can you explain? I know you got an SRT kit. What "PSI" are you supposedly putting out? What size supercharger pulley are you using? Where did you get the crank pulley? Or did that come with the kit? You mind posting some pics?
Thanks for the tips but I'm all ready finished with everything. Perhaps if I find it beneficial I will concider reconfiguring the pulley system.
For the curious I have an IG account and I post stuff up there regularly (easier than CL to be honest). Got some vids up of the finished upgrade.
7-8psi. I think it’s a 3.2” pulley. The crank pulley is a custom, double-stacked oversized billet pulley. Has a separate serpentine belt and separate SC belt. It came with the kit. Pics from a few years ago.
Uhhh, I dont see it but ok.
(Approx 8psi) Thats pretty much what I'm putting out at the moment. Its a smaller pulley to bring in the boost earlier but governed down to avoid overboost. As of now I dont have belt slippage. I reconfigured the original pulley layout and I am using a tungsten coated s/c pulley. Working well so far but needs some more "field" testing wich is gonna have to wait cause I'm currently rebuilding another GS4.
I could use that green belt though. Just in case. Hopefully they make it in the size I would need.
Thanks for the info.
Not exactly, i have an FIC 8 piggyback computer managing the tune. I got it working perfectly with the stock ECU. Passed NYS inspection for the past 5yrs with it. I do have 440cc injectors, a Walbro fuel pump and of course colder, copper plugs to also help manage fuel and spark.
Not exactly, i have an FIC 8 piggyback computer managing the tune. I got it working perfectly with the stock ECU. Passed NYS inspection for the past 5yrs with it. I do have 440cc injectors, a Walbro fuel pump and of course colder, copper plugs to also help manage fuel and spark.
Kool, can you share your info? what did you do or have been doing to pass inpections with the piggyback? how are you battling open loop enrichment, avoid triping a P-code in closed loop etc.
Thanks. appreciate it.
Hey Tank. I just replied to your PM but figured I’d also post the response here for others to read.
First, I have an AEM FIC8 piggyback. I wired everything up but without the O2 sensors, I kept them as a pass-thru so the stock ECU still manages them. Obviously, by doing this, I cannot skew/adjust the O2 signals...which is fine because I don’t need it.
Tuning for Closed loop:
I did a lot of research as to how to tune with a piggyback. It’s the opposite of how you might think. For example, you might see your WB showing 12/13AFR and might think shoot, that’s really rich, let me take fuel away. Wrong. The stock ECU may be detecting a serious deficiency in fuel (lean) and throw a ton of fuel at it therefore making the car run crazy rich. You need to work with fuel trims; both STFTs and LTFTs.
First, reset your ECU, start up and let idle. Hook up a live data scantool to your OBD2 port. The goal is to get both short term fuel trims and long term fuel trims as close to zero as possible by adjusting your fuel map accordingly in the load ranges that your car typically operates in Closed Loop (aka normal driving, normal acceleration)...no boost. Once you get dialed in, keep testing and tweaking to ensure it captures almost all scenarios, highway driving, around town, stop and go etc. Now, the stock ECU is working in HARMONY with the piggyback.
Tuning for Open Loop:
Now that Closed Loop tuning is all set you can jump to Open Loop (hard acceleration) tuning; in boost. I only utilized my Fuel Map and Ignition Map. No O2 adjustment as mentioned before and didn’t have to mess with the MAF Map (but you do need to set a MAF clamp in the setup of your tuner). Read up on.
Take your laptop, hook up to your car and start datalogging. You only need to tune now from say 15-24 PSIA if you’re running around 8lbs of boost. (14.7 PSIA is stoich, anything above that is boost). Leave everything (all rpms) alone under 15PSIA as that’s your Closed Loop tuning that’s good to go. Start driving with the datalogger recording. Do a few quick WOT pulls and pay attention to the WB while looking at computer, while looking at the road. Lol. It helps if you have someone with you. The sweet spot for SCd cars is around 12AFR, but can push to 12.5AFR to eek out a little more power, but now you’re starting to get more lean. Anything above that and you start to risk detonation (too lean). You want it to hover around these values while in boost...all the way up to your max.
When you get home, export your datalogging info to Excel if you can, and analyze. You will see how much fuel you'll need to add/subtract and/or add/retard timing at given boost/load (PSIA). From here it’s simply trial and error, constantly going out for runs and datalogging - repeat. You will get it to a good enough tune where you will never have CELs, starts up all the time, pulls cleanly and runs smooth. All while passing inspection. Note, I’ve been meaning to bring my car to a professional tuner as I feel there’s more power to be had in my setup. Example, I’m pulling almost 1 degree of timing out for every lbs of boost; which may be too much for all I know. But, I’m being safe. Also, 1-2 step colder spark plugs are a MUST and will help protect your engine.
You may know most, if not all of this but I figured I’d tell you all I know...and what works for me. I am in no way indicating I know how to tune perfectly but I must have done something right. Lol. Again, I am far from a precessional but I read countless hours on the topic.
Hey Tank. I just replied to your PM but figured I’d also post the response here for others to read.
First, I have an AEM FIC8 piggyback. I wired everything up but without the O2 sensors, I kept them as a pass-thru so the stock ECU still manages them. Obviously, by doing this, I cannot skew/adjust the O2 signals...which is fine because I don’t need it.
Tuning for Closed loop:
I did a lot of research as to how to tune with a piggyback. It’s the opposite of how you might think. For example, you might see your WB showing 12/13AFR and might think shoot, that’s really rich, let me take fuel away. Wrong. The stock ECU may be detecting a serious deficiency in fuel (lean) and throw a ton of fuel at it therefore making the car run crazy rich. You need to work with fuel trims; both STFTs and LTFTs.
First, reset your ECU, start up and let idle. Hook up a live data scantool to your OBD2 port. The goal is to get both short term fuel trims and long term fuel trims as close to zero as possible by adjusting your fuel map accordingly in the load ranges that your car typically operates in Closed Loop (aka normal driving, normal acceleration)...no boost. Once you get dialed in, keep testing and tweaking to ensure it captures almost all scenarios, highway driving, around town, stop and go etc. Now, the stock ECU is working in HARMONY with the piggyback.
Tuning for Open Loop:
Now that Closed Loop tuning is all set you can jump to Open Loop (hard acceleration) tuning; in boost. I only utilized my Fuel Map and Ignition Map. No O2 adjustment as mentioned before and didn’t have to mess with the MAF Map (but you do need to set a MAF clamp in the setup of your tuner). Read up on.
Take your laptop, hook up to your car and start datalogging. You only need to tune now from say 15-24 PSIA if you’re running around 8lbs of boost. (14.7 PSIA is stoich, anything above that is boost). Leave everything (all rpms) alone under 15PSIA as that’s your Closed Loop tuning that’s good to go. Start driving with the datalogger recording. Do a few quick WOT pulls and pay attention to the WB while looking at computer, while looking at the road. Lol. It helps if you have someone with you. The sweet spot for SCd cars is around 12AFR, but can push to 12.5AFR to eek out a little more power, but now you’re starting to get more lean. Anything above that and you start to risk detonation (too lean). You want it to hover around these values while in boost...all the way up to your max.
When you get home, export your datalogging info to Excel if you can, and analyze. You will see how much fuel you'll need to add/subtract and/or add/retard timing at given boost/load (PSIA). From here it’s simply trial and error, constantly going out for runs and datalogging - repeat. You will get it to a good enough tune where you will never have CELs, starts up all the time, pulls cleanly and runs smooth. All while passing inspection. Note, I’ve been meaning to bring my car to a professional tuner as I feel there’s more power to be had in my setup. Example, I’m pulling almost 1 degree of timing out for every lbs of boost; which may be too much for all I know. But, I’m being safe. Also, 1-2 step colder spark plugs are a MUST and will help protect your engine.
You may know most, if not all of this but I figured I’d tell you all I know...and what works for me. I am in no way indicating I know how to tune perfectly but I must have done something right. Lol. Again, I am far from a precessional but I read countless hours on the topic.
02-10-19, 09:32 PM
GS400 Custom centrifugal Supercharger Part List
