New Shift Kit Developed

[SVXRide]

Originally Posted by lechnoid

That's the thing Bill, the dyno is showing a large increase in power, and Harvey is saying that it's because of the torque multiplication that his kit provides.

Anyways, I'm off for a great afternoon of work as a technician at a transmission shop with great techs and a crappy owner. Until this evening, have fun everybody.

It's a wheel dyno, so all it's showing is an increase in power at the wheels. We constantly have discussions on the % of drivetrain loss (usually bouncing between 15% for MT and 30% for AT), thus my comment about a potential improvement of the coupling efficiency. Question for you - what's about the best efficiency you can expect from a modern TC?
Thanks.
-Bill

[Nomake Wan]

Originally Posted by lechnoid

TC lock up is when the pump and turbine are physically connected, reducing any potential slippage/inefficiency though TC operation to 0%. This was widely implemented in the 70's as a way to increase fuel economy while at cruising speeds. Whether or not it applies to the SVX I don't know, but it is not uncommon for modern converters to lock up during WOT operation to maximize power output.

Yes, the SVX has a lockup torque converter. It operates based upon fluid pressure changes regulated by Solenoid B. Generally, when travelling at a constant speed with no throttle changes (say, when cruise control is engaged), you can detect it based upon a sudden drop in revs, about 300 RPM or so.

[Trevor]

Originally Posted by TomsSVX

Also thanks to Wannarace, it is important to supply evidence other than how it feels to support a product.

As I have been thinking a lot on it, it is because the engine is still spooling power (lack of torque control) between shifts. This spooled up rotating mass is then unloaded onto the t/c when the shift completes and thus the spike...

Tom

Exactly Tom. I am unable to understand why this factor is not completely obvious to all.

The issue is whether the spike of torque available only over a very short period, serves any really useful purpose. Particularly when lined up against the disadvantages you have pointed out.

The feel of firms shifts I gather is considered sporting to those not wishing to demonstrate that they own a luxury vehicle. Exactly what is achieved, not available via a pair of side cutters, is yet to be stated, much less proven.

[TomsSVX]

Originally Posted by Trevor

Exactly Tom. I am unable to understand why this factor is not completely obvious to all.

The issue is whether the spike of torque available only over a very short period, serves any really useful purpose. Particularly when lined up against the disadvantages you have pointed out.

The feel of firms shifts I gather is considered sporting to those not wishing to demonstrate that they own a luxury vehicle. Exactly what is achieved, not available via a pair of side cutters, is yet to be stated, much less proven.

There is more to it I am sure... It must increase line pressure in accordance to its draw from the torque control in order for the clutches to hold the new-found abuse... But its no longer a question of what the kit changes and has moved on to what is it going to do to the trans itself... After going through lengthy discussions on Jason's forum I was kindly asked to piss off. I guess skepticism is frowned upon when its major components at risk

Tom

[lechnoid]

Removed by me until Harvey decides his product is complete and is ready to discuss it with the open market.

[Nomake Wan]

Drag racing is not what an SVX was designed for anyway...it's not good for it. It's a grand tourer...so I would think it'd be way more at home doing a long course at high speed.

If you want a drag car...jeez, get a WRX or something?

[TomsSVX]

Originally Posted by lechnoid

I gave it some thought at work today, and came up with a very simple thought. The only way those spikes can show the way they do on the dyno is to essentially get the automatic to act as if you had a manual and held the throttle at max while shifting. That is the only way I can think of to transfer the momentum of the engine to show at the wheels enough for a 100 hp difference.

That is what is happening. But due to the t/c being a fluid coupler and not directly driven it will lurch rather than "bang"

Tom

[lechnoid]

Removed by me until Harvey decides his product is complete and is ready to discuss it with the open market.

[oab_au]

First or all, I did not start this thread, it was started prematurely. The “Quick Change” would have been announced when it was fitted, tested, and ready for release. The uninformed debate that has ensured was not my intention, or desire.

The “Quick Change” is the result of a long held desire to improve the way the SVX Auto preforms the gear changes that many others, and I have. The gear changes are controlled by the TCU to make them very smooth and unobtrusive, by reducing the engines torque output by 50%, lowering the line pressure to soften the engagement, then raising the line pressure again and turning the engines torque back on to 100%
Unfortunately takes some time to achieve, it also has the actual band/clutch engagement taking place with a reduced line pressure that allows some slipping to take place.

To achieve the results that are needed, the Torque Control has to be addressed to allow the engine to continue to preform. If it is removed the engagement of the brake band and clutches would then take place under full power, with a reduced line pressure to the determent of the linings. The lowing of the line pressure has to be addressed also, to allow them to take the normal load

These changes to the operation for the Torque Control and the line pressure, have to be preformed only at the time they are needed, they can’t be a permanent changes, as these functions are needed at other times in the operation of the gearbox. The “Quick Change” does this by looking at the throttle pressure and engaging the control to suit the load.

The Line pressure lowering is preformed by the TCU sending a signal to the ‘A’ solenoid. The “Quick Change” intercepts this signal to keep the Line pressure high, so that the Brake band and the Clutches engage under full pressure, to prevent any slippage. The overall Line pressure is still controlled by the Throttle pressure through the dropping resistor circuit that has to be as normal. You cannot use the Small Cars Shift Kit with this unit.

The following Warning is given in the fitting instructions:

Warning: This unit should only be fitted to a gear box in good working order and condition, with a well adjusted Band and a working AWD.


Harvey.

[RSVX]

I am not saying it's beyond civil, yet.

So call this a pre-emptive obey the first rule heads up to all active in this thread.

Keep it respectful.

[oab_au]

Post removed by me for the good of the Forum.

PS. I have no intention of offending anybody. But I will defend myself with vigor.
"Play with fire... prepare to get burnt."

Harvey.

[YourConfused]

Originally Posted by RSVX

I am not saying it's beyond civil, yet.

So call this a pre-emptive obey the first rule heads up to all active in this thread.

Keep it respectful.

Every side has a point. Not all are correct. Let this thread live for the education of others.

[TomsSVX]

Thank you Harvey for confirming my assumptions of the QC's function but I still hold my personal opinion as to the long-term effects that this will have on a stock box.

Tom

[lechnoid]

Removed by me until Harvey decides his product is complete and is ready to discuss it with the open market.

[oab_au]

Originally Posted by TomsSVX

Thank you Harvey for confirming my assumptions of the QC's function but I still hold my personal opinion as to the long-term effects that this will have on a stock box.

Tom

Thank you Tom, you are welcome I am sure.
Harvey.