1/4 mile time for the SC 14.94 at 91.13mph

[SuperRunner]

Was really hoping for a 14.5, but traction issues on launch and SLOW shifts made it so I wasn't even close. Even with those fixed, my best time probably would have only been about about a 14.6 or 14.7. And the track is at 4400 feet.

Not really thrilled about the time, but I really think the elevation really hurts the roots superchargers.

Will post a vid tomorrow.

 

[kc95sc400]

Was really hoping for a 14.5, but traction issues on launch and SLOW shifts made it so I wasn't even close. Even with those fixed, my best time probably would have only been about about a 14.6 or 14.7. And the track is at 4400 feet.

Not really thrilled about the time, but I really think the elevation really hurts the roots superchargers.

Will post a vid tomorrow.

How much boost you running? How much RWHP?

My best time so far is a 13.498 at 102.14 mph. I'm ok with traction unless I try to launch at anything over 1000 rpm or so on my 2800 rpm converter. I imagine I could shave a couple of tenths with some slicks. This run was at Rockingham dragway in North Carolina. Not sure the elevation but it was 90+ degrees outside.

Mine shifts ok most of the time, bounces of the rev limiter sometimes. Try tightening you kick down cable.

KC

 

[SuperRunner]

line pressure cable is pulled tight, and I cut the wire to #4 solenoid. I didn't hit the rev limiter anymore, but the shifts are still just too slow. Accumlators need to be shimmed.

I am at 6psi intercooled. According to calculators I would be around 230rwhp...but those calculators don't account for elevation.

What psi are you running to get into the 13's like that, and what type of forced induction?

 

[kc95sc400]

I cut the wire to #4 solenoid

What does this do? Never heard of this. I've thought about shimming my accumulators but haven't decided I want to do it yet.

...but those calculators don't account for elevation.

I hear you. Elevation and heat are power robbers for sure. Every time I've been to the track lately it's like 90 degrees outside and my intake temps are around 120-130, even with the intercooler. Can't wait to make a few passes once it cools back down some.

What psi are you running to get into the 13's like that, and what type of forced induction?

Intercooled Vortech V-9, running 10 psi + at the moment. Dynoed at 310 rwhp and 268 rwtq @ 7.39 psi with the intercooler, back when it was 70 degrees outside. Since the dyno, I've put on a smaller pulley and made a few other changes which should up the numbers a little.

http://www.lextreme.com/forums/showthread.php?t=8757

http://clublexus.com/forums/showthread.php?t=312268

You'll find quite a few videos if you go to youtube and search kc95sc400.

I will finally be getting my headers next week, super excited about them. Will be back to the track soon after I install them. I think with headers and slicks (I have no intention of buying slicks right now) I could likely dip into the 12's.

KC

 

[ihiryu]

what does cutting the #4 solenoid do? I've been wanting to shim my accumlators too, but that thread on supraforums is kinda confusing.

 

[SuperRunner]

Yeah, the centrifugal is much better. Wonder how much HP they take to run. The roots witha 2.5" pully is like 50hp.

#4 solenoid helps lower line pressure during shifts to make a smoother shift. I really didn't notice too much of a difference. Shimming the accumulators and upping the base pressure is pretty much required if you want to shift better. Just by doing that alone, you can probably shave 2 10ths of second off.

 

[kc95sc400]

Hey SuperRunner, sorry to dig up this old thread.

But, I'm curious...you said that cutting the no 4 trans solenoid wire stopped you from bouncing on the rev limiter?

I just cut the wire tonight but have yet to drive the car. I shimmed the accumulators last week and I'm not really impressed. I intend to add a couple more shims later this week. Used 7.62mm's BTW.

Also, if you're interested to know, I'm down to an 8.443 (1/8 mile) since putting on my headers and going full 2.5 inch exhaust. My 1/8 time on the run I did 13.49 was 8.68 so it's quite a drop.....might be in the high 12's on street tires.

Also, have you sold your car yet? If not, interested in parting out the nitrous kit?

KC

 

[SuperRunner]

I am not sure cutting the wire to that soleniod did too much on WOT. It may have just firmed up the shifts on part throttle.

Shimming the accumulators and upping the line pressure would help more. BTW, did you also up the line pressure?

Don't think I would be interested in selling the nitrous stuff though.

Oh BTW, I ran a 14.0@100mph with a 75 shot at 5600ft elevation on bald street tires. Couldn't hit the nitrous until I was fully engage into 2nd gear, and couldn't leave off the torque converter ether. 60ft was 2.2 when I know it could do like 1.8.

 

[kc95sc400]

Cutting the wire definately did make a difference for me although it still bounces off the limiter. To me, the most notable difference is from a stop or while down shifting. The car squats noticably more. I actually found on TIS (Toyota Information System) where it says that the ECM uses solenoid 4 to control shift smoothness and to prevent vehicle squat. I can feel the difference and I noticed the difference BEFORE I found that info on TIS. Document attatched.

I did shim the accumulator, went with .3 inch or 7.62mm. Today, I'm going to throw a couple more washers in. The line pressure adjustment screw on my valve body looks different than the one shown on SupraForums but yes, I did turn it so that it pushed the regulator valve in more. And, I'm pretty sure this did indeed up the pressure.

You are selling your car right? If you decide to part out the juice, let me know.

Last night I went back to the track and ran a 8.431 @ 85.224 with a 1.88 60ft! I'm pretty sure I could have done even better but it was busy and I only got three runs in. The MPH on your run is pretty good despite the low et. I do think that bald street tires are better than new street tires, more rubber on the road. Slicks would be best of course for either of us.

I think a tenth or more could be saved if the trans would shift 1-2 before bouncing on the limiter.

KC

 

[cjsupra90]

The MPH on your run is pretty good despite the low et. I do think that bald street tires are better than new street tires, more rubber on the road. Slicks would be best of course for either of us.KC

Good MPH with a low ET is usually a sign of excessive wheel spin at the launch. This is probably due to the bald street tires which are not better then new street tires. This is because the bald tire unless shaved has had a lot of use and heat cycling to get to that point. The heat cycling causes the rubber compound to get harder over time. So even though there tends to be more rubber on the ground, the rubber is much harder and therefore has less traction ability. Now if the tires where shaved from a new tire then its a different story. This is a common trick that is used in road racing classes that requier you to run a DOT street tire and not a DOT aproved compitition race tire like say the Yokohama ADVAN AO48 which is DOT approved compitition tire, but some classes in SCCA will not allow them so the trick is to use the softest compound tire that has the least amount of tread grooves in it that is legal for the class and then have it shaved down to roughly 2/32 to 3/32 tread depth....

 

[White ls400]

This #4 solenoid is that the cause behind slow take off's and slow pick up after gear changes. Would this be detrimental to gearbox life or driveability (not concerned with shift harshness or squatting) Havnt looked yet but where is tis wire to cut off the solenoid and what colour is it?

 

[White ls400]

also would that wire being cut constantly bring up code 65 i think it was,

 

[SuperRunner]

dunno. I could definatly bring up a tranny code.

BTW, I dynoed on saturday.

On the 50 shot, I hit just over 300hp and 354ft/lbs of toque. I think my torque would have been even higher, but due to the shift points, I couldn't mash it until 4,000 RPM.

 

[White ls400]

can anyone point out the whereabouts of this wire?