floyd

ok..where are the track time slips for the GS 430's!???????????

JBrady

GREAT question...

When do you hope to go?

Here are my big fat slow 1999 LS400 slips

anks106

those are amazing times for an LS! With a 400 nonetheless, how the heck did you do that?

redgs4

jbrady, you are setting him up for disappointment posting those.

GS400_PUSHER

JBrady quick question?????? On your sig you say Deleted mufflers ( what exactly do you mean) I might have to try that mod out next month at the track

JBrady

I could tell you... but then I would have to kill you

Combination of things. Practice to get the maximum launch. The airbox mod. The muffler delete mod. 1/4 tank of fuel. Remove spare and jack and extra weight junk from the trunk. Air was PERFECT at 43 degrees and 30.4 inches mercury. Track is basically at sea level. Practice.

It is kind of fun as most people underestimate the LS400s. Lexus quotes 0-60 of 6.3 seconds and 14.8 seconds for the quarter. The LS is only 200 pounds heavier than a GS400 and has an identical engine/tranny/differential to the GS400 with the exception of a slightly more restrictive exhaust giving it a 290hp/300tq rating.

JBrady

Pusher... the muffler delete is exactly that... unbolt the mufflers. On the LS the remaining exhaust is so restrictive that removing the rear mufflers does not make it loud and probably doesn't give any real measureable power but it does save 30-40 pounds.

BTW, look at my slips, the 60ft time were 2.2 seconds. Without a limited slip diffferential it is very hard to put down power out of the hole. With a LSD and sticky tires I should be able to cut 2.0 second 60fts and on all 3 of the above slips that would have give me 13 second ETs

Here is a picture of the muffler delete mod

GS400_PUSHER

Thanks! You know I got a 2.0 60ft on my 20s last year but I only hit a 14.3 @ 97mph. This year I will try again but with the LSD. First with 20s then with 16s and see what the difference will be.


P.S. what are those muffler looking things in the pics you posted?

JBrady

Yeah, 60 foots are critical any difference is usually magnified by the end of the run. Depending on the car a tenth of a second quicker 60 foot can equate to up to 2 tenths quicker ET. This is because the launch is so critical and the relative speed is so slow vs the end of the track.

BTW, from memory, you do have the PI torque converter correct? That makes a BIG difference provided you get traction. I have been thinking about a TC for a long time. Also, a 14.3 on 20s is still very good. 20s are show... not go.

The muffler looking things are what I refere to as silencers. They are essentially mufflers with a very strange side case entrance. These do a good job muffling even without the back mufflers on. The non-CA SC400s have a similar units.

GS400_PUSHER

Yes I do have to PI TC. I know when I first tried to lauch at the track when i got my TC installed I SUCKED It took awhile to get that thing down pack! You actually can be slower if you don't know how to lauch it....my first try with it was 15.5 then 15.0 on the second try by the end of the night I was 14.6 That following Friday (test and tune) I let some psi out the tires I think it was set @ 21psi when I hit the 2.0 60ft. and ran the 1/4 @ 14.3 mph was 97

ChrisK

iTrader: (1)

jbrady,

Can you tell me in details how you lunched your car to get 2.2 in 60'?

Thanks,

JBrady

Chris,

Practice.

Turn off the VSC.

Shallow stage the car, just barely roll into the second beam to light the second stage lights.

I anticipate the start of the 3 yellows and raise RPM to about 2000 with my left foot on the brake (brake torquing).

On the last yellow I release the brake and "roll" into the throttle trying for max power without tire spin.

Again, the above takes practice. Remember to minimize the time you are loading the torque converter by brake torquing.

With the throttle by wire on the 98+ engines it is very important NOT to spin the tires as if they do the engine flashes to high rpm (while spinning) and the electronic delay is not quick enough to allow modulating the throttle under this condition. You have to lift completely, let the spinning stop, then get back into the throttle and by that time the run is shot.

ChrisK

iTrader: (1)

Thanks John,

My best two runs at about 100 degrees:

R/T____.546____.684
60'_____2.261___2.280
330____6.279___6.329
1/8_____9.589___9.621
MPH___74.04___74.49
1000___12.456__12.474
1/4____14.858__14.870
MPH___93.50___93.71

Before I thought that I was having problems with top end power, but after comparing my runs with yours I now believe that my problem is lunching the car correctly.

JBrady

Chris, 100 degrees is HOT and will cost top end power. The exhaust manifolds are one reason for this but you also make certain you have GOOD gas in the tank... and... that you have been driving aggressively on good gas for at least a day before racing... especially important in hot weather.

Here are the numbers I ran on an 82 degree day. This was my 3rd time to the track with the car and I was getting more out of it (the car just kept getting stronger the more I raced). Notice the similar numbers to your run but with higher MPH indicating power. Interestingly you were faster at each point except the 60ft and 1/4 where I just nudged you but I was moving faster at both the 1/8th and the 1/4.

RT - 0.619
60' - 2.257
330 - 6.333
1/8 - 9.629
mph - 74.79
1000 - 12.462
1/4 - 14.828
mph - 95.72

Here is my next trip with better weather, 73 degrees.

RT - 0.636
60' - 2.229
330 - 6.222
1/8 - 9.468
mph - 76.00
1000 - 12.252
1/4 - 14.577
mph - 97.29

So, keep practicing. Pray for good weather

ChrisK

iTrader: (1)

Thaks John.