IS2000

The GS430 has a redline of around 6200rpms but even with the power ECT mode on, the car refuses to rev past 5800rpms. Is this normal? All my other automatic cars kiss the redline before shifting.

bitkahuna

iTrader: (20)

It's normal - max power doesn't come at redline.

Mean Gene

Bit - I thought that the factory rated the V-8 at 300 HP at 6k? My dyno sheets also show that max power occurs ( for me ) at 6100 rpms ( snuck past the rev limiter somehow!! ). I have SRT's intake & Borlas but the power curve ( after mods ) tends to parallel the baseline ( factory ) results.
IS2 - Don't know why your 430 won't spike the redline. As I said above, I can go past my 6k redline every time ( even more often with the 3.76 gears ).:eek:

IS2000

Bitkahuna,

When you say "normal," does this mean your GS also shifts below the 6200rpm redline? Though it's true that you do not produce more power at higher rpms (after peak), it is still better to do so simply because when the car upshifts you will be a few hundred rpms higher which immediately lands you closer to the car's power band.

e.g. 4.3L does 300HP@5600 - if the car shifts to 2nd at 5800rpms, tach will drop roughly 1000 - 1500rpms. Meaning 2nd gear will effectively start at 4300 - 4800rpms. Now if the engine were to kiss the redline at 6200rpms, subtracting 1000 - 1500rpms on the 2nd gear upshift, lands you at 4700 - 5200rpms.

Obviously, between 4300 to 4800rpms vs 4700 to 5200rpms, the latter puts you much closer to the car's peak power at 5600rpms. Thus, the car should go faster.

Mean Gene,

I assume that your GS430 kisses redline on every upshift at full throttle? If it does, what could possibly be wrong with mine?

bitkahuna

iTrader: (20)

Remember guys, HP is for top speed, but TORQUE is for acceleration.

GS430 (from Edmund's)...

Horsepower: 300hp @ 5600 rpm
Torque: 325ft-lbs. @ 3400 rpm

No way it's efficient to shift at redline with max torque so low.

I can't say I try to redline the car when driving, but I don't think it EVER has at WOT.

If Gene's does, it's possibly because of his different gearing.

GlobeCLK

iTrader: (5)

I checked my REV limit on my Rev-Speed meter and my highest rev went to 6300+rpm once. Does that mean I'm over-revving? Or the redline on the tach is pretty conservative?

Mean Gene

Globe - I wouldn't worry too much about spinning the engine a few hundred rpms above redline unless U do it EVERY time!! There might be some kind of "flash-speed" reading that you're getting on the tach as well. Bit's correct about my gearing causing me to hit my rev limiter but I've learned how to use the E-shift ( which the 430 doesn't have, unfortunately ) by pressing the upshift button at 5800-5900 rpms. By the time the rather sluggish tranny actually does the shift, I'm right at 6200 which my dyno sheets show to be where my engine makes the maximium power. I bought the differential from Will Kirksena because his S/C 'ed GS was making too much power ( is there REALLY such a thing?? ) & traction became a problem for him. He warned me about the possibility of spiking the limiter but I still think it's a great mod for those who wish to stay naturally aspirated. It's been almost 2 years but I do recall my GS4 ( when totally stock ) touching a little over 6k before it upshifted ( when left in "Drive", obviously ).
IS2 - If Bit's engine power info is correct ( & it always is! ), then there's no point other than to hurt parts by buzzing the engine up way beyond the power peak. Actually, in my 25+ years of drag racing I've found that the best way to determine optimium shift points is to know your torque & horsepower peak rpms. U want to upshift at an engine speed that will drop U back close to the peak torque range ( as Bit said, torque gets ya moving & horsepower takes ya thru the timing trap ). If U need to go SLIGHTLY beyond the maximium horsepower rpm point then do so. As my GS is set up now, an upshift at 6200 drops me back to 3400 rpms which is slightly above where the T/C has locked up & slightly below where the V-8 is starting to make good torque - actual torque peak rpm is 4100. With much experimentation, this shift point seems to yield the best quartermile times. See where that 5800 shift point drops ya back to - if it's close to the 3200-3400 mark, then I'd say that Lexus has done their acceleration homework well!!

IS2000

Mean Gene,

I'll double check at what rpm 2nd gear will drop into after shifting from 5800rpms. I'm just not used to automatic cars shifting below their respective redlines. My mom's Merc, friend's M3 and even a CR-V kiss their redlines before shifting. I just don't understand why my GS430 doesn't. Oh yeah, our old LS400 which we already sold, kisses red line as well.

I know different "strokes" for different folks literally apply to engines as well but if anyone here who owns a stock GS430 that happens to shift at 5800rpms as well, please let me know. I feel more comfortable knowing that it is the norm.

ShowGSLuVv

Hey IS, I posted a reply in the other thread u had going, But I have a 02 GS430 and it does the exact same thing ur talking about, the only way I had it kissin the redline was by using the gateshift, By the way what year is ur GS?

ShOwGS