Jump to content
SAU Community

Recommended Posts

Let us know your thoughts on the dog box after you have a drive with one Piggaz. I'm going to be in the same boat as you and am not sure about driving with one on the street.

CHeers

Edited by Chris32R

ppg straight cut dogbox would be epic.

Would be, but still being a road car I want a helical 5th for freeway use so it'll be helical

dogs.

Let us know your thoughts on the dog box after you have a drive with one Piggaz. I'm going to be in the same boat as you and am not sure about driving with one on the street.

CHeers

Will do. Either way, decision is made so ill just have to learn.

What's your setup?

They are easy on the street. To be honest, they do take a week or two to adjust to the new style of changing gear and the change in speeds you get in each gear. If i push mine to 8000rpm my speedo just nudges 100kph in first gear! Power levels, final drives and tyre size do affect this. .

Once you get the hang of no clutch, you will never want to go back a synchro box. You realise they are purely for comfort and that is it!

They are easy on the street. To be honest, they do take a week or two to adjust to the new style of changing gear and the change in speeds you get in each gear. If i push mine to 8000rpm my speedo just nudges 100kph in first gear! Power levels, final drives and tyre size do affect this. .

Once you get the hang of no clutch, you will never want to go back a synchro box. You realise they are purely for comfort and that is it!

Can you downshift easily with no clutch while braking or do you have to use the clutch? I suppose the latter because the box would be loaded up under braking?

Also, how does power level affect RPM/speed ratio in any way? - Unless of course your clutch is slipping!

Can you downshift easily with no clutch while braking or do you have to use the clutch? I suppose the latter because the box would be loaded up under braking?

Also, how does power level affect RPM/speed ratio in any way? - Unless of course your clutch is slipping!

No, you can down shift without the clutch if you heel toe correctly and match the revs. The slight blip of the throttle counteracts the deceleration force to unload the dogs to allow it come out of gear. As you go through neutral, the throttle blip will speed up the gearbox internals to the same speed to allow them to engage without clunking, banging or simply not going in.

The way a dog box work vs a synchro is very different.

Power affects it slightly. More power means more force. More force means more output. More output means more speed.

For example, at one power level i got 10kph/1000rpm in 1st gear. After adding 100awkw and changing nothing else, i get just over 12kph/1000rpm in 1st gear now. So it isnt a huge factor in terms of how it affects your speed. tyre size and final drive would make more noticeable differences.

No, you can down shift without the clutch if you heel toe correctly and match the revs. The slight blip of the throttle counteracts the deceleration force to unload the dogs to allow it come out of gear. As you go through neutral, the throttle blip will speed up the gearbox internals to the same speed to allow them to engage without clunking, banging or simply not going in.

The way a dog box work vs a synchro is very different.

Power affects it slightly. More power means more force. More force means more output. More output means more speed.

For example, at one power level i got 10kph/1000rpm in 1st gear. After adding 100awkw and changing nothing else, i get just over 12kph/1000rpm in 1st gear now. So it isnt a huge factor in terms of how it affects your speed. tyre size and final drive would make more noticeable differences.

Cool that makes sense. So to downshift without the clutch you would be braking into the corner, jab and hold the throttle with your heel and then swiftly put it into the next gear?

I understand the difference between how they work, just wondering what driving styles work and don't work.

I believe you can drive a dog box like a synchro box, ie) clutched shifts etc. but you must be affirmative with the gear changes. (See PPG how to drive a dogbox video)

However, you obviously can't drive a synchro box like a dog box, as the synchros won't let the shifter slam between gears without being rev matched.

I still disagree with your statement that more power = more speed unless you have some technical description.

Everything is meshed in a manual box, so assuming there is no slippage the crankshaft speed is locked to the wheel speed.

Wheel rotations per minute is always going to be equal to something like =

RPM x clutch slippage factor / gear ratio / final drive ratio

There is no way I can see that more power can produce a higher wheel rotational speed at a given RPM.

Additionally, you are not using any more power to maintain 10k/1000rpm now than you did before, the amount of power used would be exactly the same, but the throttle position might be different to maintain the same speed.

Edited by Jazzadub

Straight cut dog box will be annoying on a street car - unless you love the loud sound of the whining gears. Not sure how loud the whine is on the straight cut PPG, but the Trust straight cut dog box is very loud. Doesn't help if you have a quiet exhaust either. Let me know when you meet up to test drive the PPG (if you haven't already) as I would like to compare and might swap to a PPG and leave the Trust to the race car.

Straight cut dog box will be annoying on a street car - unless you love the loud sound of the whining gears. Not sure how loud the whine is on the straight cut PPG, but the Trust straight cut dog box is very loud. Doesn't help if you have a quiet exhaust either. Let me know when you meet up to test drive the PPG (if you haven't already) as I would like to compare and might swap to a PPG and leave the Trust to the race car.

Charlie, unless you want straight cut 1-5 (straight cut 5th would get annoying on the freeway), PPG only do a helical 1-4 helical dog with a synchro 5th (standard ratio if you wish).

I still haven't met up with Sime, is the helical dog something you're interested in?

Unfortunately, I don't think the helical will handle what I have to throw at it. The straight cut box will end up costing close to what an OS Giken sequential will (Well, close enough to make the OS Giken Seq. a viable option) The OS G is also helical cut and can handle 1500hp.

Unless you need dog 5th, helical dog 1st-4th is the best for the street because it doesn't make any noise.

After the first couple of months hating life that you just blew a shit load of money on something noisy you can't drive, come and talk to me once that's over and let me hear how you'll never want a synchro box again. Ever.

They are the ultimate.

Unless you need dog 5th, helical dog 1st-4th is the best for the street because it doesn't make any noise.

After the first couple of months hating life that you just blew a shit load of money on something noisy you can't drive, come and talk to me once that's over and let me hear how you'll never want a synchro box again. Ever.

They are the ultimate.

That's what I keep hearing!

What's in yours, Paul? 1-4 helical or 1-5 straight cut? I've seen a few of your vids, particularly at Coota. You're not nice to them at all!

Helical dog 1-4. I broke a selector after over 30,000k's, and replaced a few bits from it last year, that was 6 years worth of abuse that you've seen on those videos. It's the only way the car gets driven, and I might add that both the guys who work on the car had been learning to drive on it as well.

When I broke the selector it was partially my fault, but most of the wear would have been caused during the initial period of me getting it together.
It does take time to learn though, you can't just jump in one and think you're Fangio, it will bite you in the arse and if you are offered a test drive, you're wasting your time unless someone experienced is in the driver seat.

That's decent!!

What have you done for a 5th gear? Still the standard unit? How often are you up 5th? I'm a bit frightened to bust it.

It's stock, I used to worry about busting it but I did the Snowy Mountains 1000 and had 5 passes into 5th, certainly reminds you how much you hate synchros when you go to shift in 5th fast.

  • 2 months later...
  • 2 weeks later...

After months and months of research, I've decided to go the OS88. Went for a drive in one and it was awesome. Quiet in gear, bit of clunking between gears but who cares about that, 4 choices of ratios and 6 speed. It also bolts straight into a R33 GTR so no shaft/transfer case changes.

It won't happen this year, but it'll happen. :)

Won't that be a bitch to drive on the street though?

Meh, I'll live. It's just different.

It ain't a daily, when I take it out I'm giving it a hard time.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Latest Posts

    • Lucky man, who owns it in the family? Any pics? 
    • The engine stuff is Greg Autism to the Max. I contacted Tony Mamo previously from AFR who went off to make his own company to further refine AFR heads. He is a wizard in US LS world. Pretty much the best person on earth who will sell you things he's done weird wizard magic to. The cam spec is not too different. I have a 232/234 .600/603 lift, 114LSA cam currently. The new one is 227/233 .638 .634. The 1.8 ratio roller rockers will effectively push this cam into the ~.670 range. These also get Mamo'ified to be drilled out and tapped to use a 10mm bolt over an 8mm for better stability. This is what lead to the cam being specced. The plan is to run it to 6800. (6600 currently). The Johnson lifters are to maintain proper lift at heavy use which is something the LS7's supposedly fail at and lose a bit of pressure, robbing you of lift at higher RPM. Hollow stem valves for better, well everything, Valve train control. I dunno. Hollow is better. The valves are also not on a standard valve angle. Compression ratio is going from 10.6 to 11.3. The cam is smaller, but also not really... The cam was specced when I generated a chart where I counted the frames of a lap video I had and noted how much of the time in % I spent at what RPM while on track at Sandown. The current cam/heads are a bit mismatched, the standard LS1 heads are the restriction to power, which is why everyone CNC's them to get a pretty solid improvement. Most of the difference between LS1->LS2->LS3 is really just better stock heads. The current cam is falling over about 600rpm earlier than it 'should' given the rest of my current setup. CNC'ing heads closes the gap with regards to heads. Aftermarket heads eliminate the gap and go further. The MMS heads go even further than that, and the heads I have in the box could quite easily be bolted to a 7.0 427ci or 454 and not be any restriction at all. Tony Mamo previously worked with AFR, designed new heads from scratch then eventually founded his own business. There he takes the AFR items and performs further wizardry, CNC'ing them and then manually porting the result. He also ports the FAST102 composite manifold: Before and after There's also an improved racing crank scraper and windage tray. Helps to keep oil in the pan. Supposedly gains 2% power. Tony also ports Melling oil pumps, so you get more oil pressure down low at idle, and the same as what you want up top thanks to a suitable relief spring. There's also the timing chain kit with a Torrington bearing to make sure the cam doesn't have any thrust. Yes I'll post a before and after when it all eventually goes together. It'll probably make 2kw more than a setup that would be $15,000 cheaper :p
    • Because the cars wheels are on blocks, you slide under the car.   Pretty much all the bolts you touched should have been put in, but not fully torque up.   Back them off a turn or two, and then tighten them up from under the car with the wheels sitting on the blocks holding car up in the air.
    • Yes. Imagine you have the car on the ground, and you mine away all the ground under and around it, except for the area directly under each individual wheel. That's exactly how it'd look, except the ground will be what ever you make the bit under each wheel from
    • Yes, if you set the "height" right so that it's basically where it would be when sitting on the wheel. It's actually exactly how I tighten bolts that need to be done that way. However....urethane bushes do NOT need to be done that way. The bush slides on both the inner and outer. It's only rubber bushes that are bonded to the outer that need to be clamped to the crush tube in the "home" position. And my car is so full of sphericals now that I have very few that I need to do properly and I sometimes forget and have to go back and fix it afterwards!
×
×
  • Create New...