Drivetrain Power Loss.

[JDM RunX]

I was just driving around the other day and it really hit me that when shifting I'm really losing alot of time & power between gears 1-2-3. It is almost as if I HAVE to slip a little clutch to land at 6200rpm when shifting. I'm no pro but I've tried to shift as fast as I can and still I lose around 2000rpm when shifting. Is this normal? Is my drivetrain weakening? I dont smell any clutch burning and I dont hear any noise in the gearbox, I also dont feel any obvious slipping. How much of an improvement can I expect from upgrading my clutch, pressure plate and flywheel?

As I mentioned in another thread, my friend just bought a 2001 RunX and when I drove it I had not problem hitting 6300 even 6400 shifting from 1st to 2nd.

Edited July 8, 2005 by JDM RunX

[lucio_libre]

Did you lower your car recently :)

[ZEEROLLA]

Its normal mate to lose around 2000-2500rpm for 1-2, 2000rpm for 2-3 but 3-4 you loose only 1500-1700rpm. Its the gear ratios and road speed that determines your revs. Lowering your car, having larger overall diameter wheels etc all affect your revs and road speed.

My advice is don't worry too much, if you put your mates 15inch wheels on your car it will drive more like his. ;)

Z

[JDM RunX]

Thanks. I haven't lowered the car yet but by this time I'm pretty sure that my 17" Rim & Tyre combination has really affected my performance in a negative way. I shouldn't have sold my stock rims. :(

In any case, what can I expect from upgrading the drivetrain components. Will I get back some of what I lost after changing my Rim & Tyre?

Edited July 9, 2005 by JDM RunX

[ZEEROLLA]

Thanks. I haven't lowered the car yet but by this time I'm pretty sure that my 17" Rim & Tyre combination has really affected my performance in a negative way. I shouldn't have sold my stock rims.  :(

In any case, what can I expect from upgrading the drivetrain components. Will I get back some of what I lost after changing my Rim & Tyre?

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Upgrading the drivetrain will do nothing much if your original isn't worn out. Do you know how heavy your rims are and what is the overall diameter compared to stock wheels? Also what sort of tyres are you using? By reverting back to stock rims i believe your car should be at least in par with your mate's.

Also remember your driving technique is crucial too. If your mate managed to land LIFT at 6400rpm and you were at 6000rpm only or 6200rpm for that matter with your bigger wheels and different tyres etc etc.. taking into consideration all other variables.. you gonna lose for sure even with your CAI.

For myself personally i haven't been able to land LIFT1-2 without bouncing on the limiter in 1st gear but could also be due to my technique. I stand a 9/10 chance of landing LIFT if i hit limiter in 1st but maybe 3/10 chance if i don't. But some people say if you hit limiter you actually lose crucial time, but for me i feel that if i get a good 1-2 shift and land LIFT even if i touch limiter for a split second, the car is still quicker than if i don't as i have landed LIFT and the car pulls immediately. Makes any sense? sorry i am not too good at explaining myself sometimes..

Z

Edited July 9, 2005 by ZEEROLLA

[Zuban]

I have 17" rims on my corolla and i can no longer hit lift

1-2nd gear, but 2-3rd and beyond i have no problem, but it is close, I do feel that the rev counter is always slightly behind and holding it just that little bit longer in each gear will put you a little higher into the next gear, and keep you in lift, sometimes with the corolla you need some faith, otherwise you would buy a civic type r loll!

The corolla has a very tight close ratio box, figure out the difference between short and close yourself. This box has won me many races, forget 0-100kph it counts for jack on a track, or anything other than sprint. Learn to use that box and suddeny things become clearer.

[Danthuyer]

engine mounts ;)

[ZEEROLLA]

engine mounts ;)

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I heard about engine mounts affecting performance negatively, i think its on Best Motoring and they tested all JDM hi-performance cars with around 60,000kms.

[shaohaok]

engine mounts ;)

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I heard about engine mounts affecting performance negatively, i think its on Best Motoring and they tested all JDM hi-performance cars with around 60,000kms.

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how so negatively

[ZEEROLLA]

engine mounts ;)

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I heard about engine mounts affecting performance negatively, i think its on Best Motoring and they tested all JDM hi-performance cars with around 60,000kms.

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how so negatively

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Yeh Craig why? :P

I think BM said there deteriorated engine/transmission mounts affect the car's balance.. ie. much more movement in the engine and tranny, engine and tranny sagged (lower down in the engine bay)? Don't know about straight line speed but when running on a racetrack the handling balance was definitely affected. This episode of BM i have is in Jap only with no subtitles so don't take my words for it but they tested a TypeR with close to 60,000kms but on the dyno it still produced the same power as a new TypeR and 1/4mile time was quicker than a brand new by a couple of milliseconds But handling sucked, understeered too much instead of the normal slight oversteer you will see in early TypeRs.

*Read on only if you are interested in the rest of the vid andother cars they tested:

For those interested they also tested WRXs, GTRs, EVOs, Silvias, Supras, RX7s, and an NSX. Only the 2 NA hi-performance cars had no power loss and no loss in 1/4mile time :D . ALL TURBO CARS loss at least 1/4 of their claimed power output! ALL TURBO CARS needed boost up and new computer to bring output back up to NEW, except the GTR and Supra with more than expected gains after tuning.

AWD cars were the worst when it came to wear and tear (surprise surprise..) the WRX broke 2 driive shafts, needed new turbo and cost a hefty amount to REFRESH. The EVO needed new clutch, suspension componets and engine tune but a hose blew itself when they raced the car. The GTR needed new gearbox seals, suspension components, boost up and new ECU tuning but it went on to do a 12.8sec 1/4mile. The Supra they had was low kms and used for the track and only needed slight mods like new brake discs, boost up, better suspension components and was very quick. Silvia needed new suspension components and different LSD. RX7 had boost up and suspension tune, handling was exceptional on track but lacked straight line speed.

So if you have the dough go ahead and REFRESH 2nd hand Turbo cars like the GTR and Supra since you can't get them new in Oz. Otherwise better to stick with NA reliability if you are after 2nd hand hi-performance cars ;)

Edited July 14, 2005 by ZEEROLLA

[Danthuyer]

engine mounts ;)

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I heard about engine mounts affecting performance negatively, i think its on Best Motoring and they tested all JDM hi-performance cars with around 60,000kms.

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OH well

IF and when I get them done I will update you all and let you know if the car received any gains

[SILVABULLIT]

Looking into engine mount kit as well ;)

[oz_viking]

Lowering your car, having larger overall diameter wheels etc all affect your revs and road speed. 

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Zee,

I'm interested to know why you think lowering alone would affect acceleration...

[ZEEROLLA]

Lowering your car, having larger overall diameter wheels etc all affect your revs and road speed. 

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Zee,

I'm interested to know why you think lowering alone would affect acceleration...

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Lowering alters the suspension balance and traction either possitively or negatively depending on how well your suspension balance is after lowering. More traction means less wheel spin but i found that 1-2shift with a bit of wheelspin is good to keep revs above 6000rpm, but wheelspin on take-off is just a waste of time ;) But how much lowering affects accelration is up for scrutiny since it can be so marginal. But i believe in JDM RunX's case, there are way too many variables involved but from the mechanical standpoint the lowering and rims/tyres are the only modifications he did to differ from his mate's car (not to menton the CAI).

Z