Tuesday, April 01, 2008 - 02:38 pm, by: Khris Cox(Kc95sc400)
Hey Soarer Central! I have a supercharged Lexus SC 400 and thought you all would be interested in seeing it. I won't go into 100% full detail here unless asked, but I'll post links and such.
Mods..........
Vortech V-9 supercharger CCW F-trim mounted using Lextreme's "The Fish". Large front mount intercooler. Bypass valve being vented to atmosphere. Blowing 8-10 lbs of boost.
Running in speed density via the MAFTPro fuel computer, GM 3 bar MAP sensor, and a GM IAT sensor. http://www.maftpro.com/tproinfo.shtml The MAF sensor is sitting on a shelf in my garage.
Supra 315's and a Walbro HP pump.
Dragon torque convertor with 2800rpm stall.
Stock gears with a Supra Torsen LSD.
EGR blocked. Coolant bypassed for the IAC valve and throttle body.
Center cat deleted, dual 2.5 inch exhaust with H-pipe. Still waiting on headers form EKtuning.
Probably forgetting a few things, but that's the bulk.
Performance..........
My best dyno number is 318rwhp and 288rwtq with 7.5psi. For some reason, I have trouble making full boost on the dyno. I see 9+psi on the street so I'm probably making more power than the dyno results. The graph pictured is not the best numbers wise but it's the best run starting at a lowish RPM.
On street tires (OEM size) I can consistently run 0-60mph times in less than 5 seconds. I've timed a few 0-60mph runs in the 4.5 to 4.6 range. This is with stock tire size, I can't actually lunch at my stall speed because of tire spin.
Here's an example...
If you go to youtube and search kc95sc400, you'll see all my vids.
Haven't been to a track yet. I may be going to an eigth mile track this Thursday. I may eventually make the trip to the nearest quarter mile track, about an hour and a half away.
Recent pic of my setup. The intercooler is not installed in this pic but you can see it in the "show and tell" vid if you search my username on youtube.
Well, I think that's about it for my first post. Second post coming right up.
KC
Edit, forgot something.
Build threads, if you want to be bored by all the trials, errors, problems and triumphs you can go to one of these.
Club Lexus - http://www.clublexus.com/forums/showthread.php?t=312268
Tuesday, April 01, 2008 - 02:45 pm, by: Khris Cox(Kc95sc400)
Something I'd like to share. I think this could help ALL the supercharged guys, roots and centrifugal alike.
On some of my dyno runs, my boost curve is really funky, wavy is a good word. The dyno operator suggested that my belt may be silently slipping a little. So I made this....
It's an L-bracket bought from the hardware store, cut to size. I drilled and tapped a hole for a 12mm bolt. I bolted the bracket to the engine using one of the existing tensioner bolts. I then put a 12mm bolt into the drilled and tapped hole, tightening the bolt onto the little "nub" that sticks out on the OEM tensioner. Used a 12mm nut to lock the bolt into place. The difference in belt tension is like night and day!
I don't know if my boost curve is any better, but the car does seem a bit more responsive on the road!
Wednesday, April 02, 2008 - 08:38 am, by: Khris Cox(Kc95sc400)
Paul Drane wrote on Tuesday, April 01, 2008 - 05:23 pm:
Hi Khris, good to see you posting up what you have achieved, and that you have sorted you problems out.
Just need more boost now
Hey, thanks. I will make a list of the problems I've had a bit later. I have had some interesting ones.
As far as more boost, I'm using a 12psi pulley (14psi with a 6.5 inch crank pulley) and I'm getting 9ish psi on the street. I'm not sure why I can't get it on the dyno. Next dyno I'll go to one that can actually load the car a bit more. As far as on the street, the intercooler must be eating up some of the 12psi.
I don't think I could use a smaller pulley (2.4 inch now) so I think my best bet for more power would be a bigger blower. No plans to upgrade for now.
Thursday, April 03, 2008 - 01:02 am, by: Khris Cox(Kc95sc400)
Neil Griffiths wrote on Wednesday, April 02, 2008 - 07:30 pm:
Put your car on the dyno.
Remove your invention.
Then watch the belt, that will give you the answer.
It ain't called a * Tensioner * cause they run out of words,,
Thanks for all the kind words Neil!
I think it's fine.
If my pulleys fly off and start passing me...or...the crank and or power steering pump seals leak so bad that the belt flings oil everywhere and the car starts on fire...or...if the blower starts turning backwards because the belt is too tight...I'll let you know and you can say "I told you so".
Thursday, April 03, 2008 - 11:24 am, by: Khris Cox(Kc95sc400)
This is what I did for the oil drain..
I removed the lower pan and the baffle, drilled a hole in the upper pan from the inside.
I was VERY carefull about where I drilled the hole, took me about 20 minutes to remove the pan and about 45 minutes to decide where to drill. I was very nervous.
I don't remeber which size I used, but I tapped the hole for NPT and intalled an NPT pipe nipple with sealer.
I then threaded a NPT bushing on the inside with some more sealer. I know, it's ugly. I've never been good at making sealer look pretty.
I THEN installed an NPT elbow. I angled the elbow slightly upwards for better drainage.
In the picture, I had installed a plug. Later when I put in the supercharger, I took the plug out and installed a hose barb fitting.
I did this 5-6 months ago and am having no problems with it. Every time I get my car on the lift, I double check for leaks and never find any.
KC
Neil Griffiths Goo Roo NSW I have a Cadillac and a Supercharged Manual V8
Friday, April 04, 2008 - 08:02 am, by: Rich O'neil(Kiwiinaus)
Everybody [ except Neil ] tries to eliminate belt slip to the max and yes excessive belt slip is not good . BUT a little bit of belt slip is not such a bad thing , just think about why the belt is slipping a little bit and where all that load would go and the damage it could do if the belt didn't slip a little bit . It kind of act's like a clutch , eliminating load spikes = being kind to mechanical things . Also Neil is right on the money with NOT restricting the movement of the tensioner , get someone to turn your air con on while you look at what the tensioner does....that's why it's there and with the tensioner working as it should you will probably have less belt slip as the movement of the tensioner absorbs some of the load shock that causes belt slip . Also get someone to rev up the car to about 4000 RPM and then back off the throttle , see what happens to the tensioner in that situation , with the tensioner effectively locked off where is all that load going !!!
Neil Griffiths Goo Roo NSW I have a Cadillac and a Supercharged Manual V8
Sunday, April 06, 2008 - 01:13 am, by: Khris Cox(Kc95sc400)
That's nice! I assume the motor is built for 18+ psi? You have a seperate belt for the blower? Is that the ?Opcon? blower?
I'm kind of worried about you upper radiator hose being kinked like that. If you don't already have a plan for fixing it, I would suggest getting a plastic 90 degree that is made for coolant.
KC
Neil Griffiths wrote on Saturday, April 05, 2008 - 06:55 pm:
Khris, I have a Pre-Tensioner on this 8 Rib setup.
It WILL soon be pulling this Twin Screw up to 18-20psi.
Sunday, April 06, 2008 - 01:20 am, by: Khris Cox(Kc95sc400)
Here's a couple more pics of my current pipe routing. Except, I have the intercooler in place of the two pipes in the front and the MAF is no longer in the pipe.
Amazingly, the 2.5inch pipes does fit under the headlight with little mod and very little interference.
Here's a pic of where the intercooler sits.
KC
Neil Griffiths Goo Roo NSW I have a Cadillac and a Supercharged Manual V8
Sunday, April 06, 2008 - 01:10 pm, by: Khris Cox(Kc95sc400)
Ok, list of problems I've had, some very interesting ones.
For a month after getting everything together, I wasn't able to build any boost. Turned out to be the EGR valve, was leaking all my boost. I blocked it off and then had boost.
I have blown the tops off of 2 MAF sensors! I did attempt to put the MAF on the inlet side of the supercharger but, it turns out there's not really enough room. Now I am finally running MAP, thank God.
The OEM FPR diaphram busted, leaking vac / boost.
I have replaced just about every vac line on the car due to leaks. I would fix one leak and then another would start.
The fuel injector O-rings, where they seal into the manifold, were leaking boost pressure. This is when I decided to put in the 315's, along with all new o-rings and isolators of course.
I didn't know about the passenger side valve cover to throttle body vent hose, opps.
I didn't know that, even being an OBD1 car, that the ECU controls both banks of the engine seperately. This caused me a ton of problems due to the fact that my wideband is currently installed into the drivers side pre cat o2 sensor spot. I figured out a fix for until I get my headers.
I know there's a few more but those are the main problems I've had. Mostly stuff that should be expected when putting boost on an NA car with 130k+ miles on the odometer.
Tuesday, April 08, 2008 - 10:05 am, by: Khris Cox(Kc95sc400)
I don't know if I mentioned it here earlier, but I will be going to an 1/8 mile track on Thursday. I expect a good time. I'm hoping for 8.5 seconds or better.
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Khris! 
and a Supercharged Manual V8 
