Smurfette R32 GTR build.

[Piggaz]

What kinda money are they after for an OS88?

[khezz]

2 hours ago, Piggaz said:

What kinda money are they after for an OS88?

Got the os88 with new os quad plate for 17500. 

[khezz]

2 hours ago, Piggaz said:

If you want to do it properly you need to install a gear position sensor BEFORE the box goes in. You’ll then need a strain gauge. Depending on the strain gauge used factor in around $2500 to do this.

Here are a couple photos of the sensor I used on the OS88.

The strain gauge was the “Motorsport systems” item. Same as what they use in V8 Supercars. It’s about $1500, made in Sydney.

Pardon my ignorance but what is the gear position sensor for? Is this part of the requirement for flat shifting?

[Piggaz]

1 minute ago, khezz said:

Pardon my ignorance but what is the gear position sensor for? Is this part of the requirement for flat shifting?

Gear position sensor is so you know where everything is. If you don’t have it then you can only use a set time and hope that you have completed the motion of the change before it restarts ignition. 

[khezz]

3 minutes ago, Piggaz said:

Gear position sensor is so you know where everything is. If you don’t have it then you can only use a set time and hope that you have completed the motion of the change before it restarts ignition. 

So I am not using clutch less shift and depress throttle between shifts I won't need it?

I will get one, I am just trying to learn.

[reaper]

No point having a sequential dog box if you aren't going to have flat shift enabled imo.

Better for the box if you let the ecu do the work.

Powertune have a kit to retrofit the box with everything thats needed for proper clutchless shifting.

Pair it with an electronic throttle and you get clutchless down shift and auto blip on down shift if you want.

This is how I have my Samsonas setup in my gtr and it works well.

[iruvyouskyrine]

On 4/25/2021 at 2:02 PM, Piggaz said:

Gear position sensor is so you know where everything is. If you don’t have it then you can only use a set time and hope that you have completed the motion of the change before it restarts ignition. 

lmao imagine spending 17k on a box and having to retrofit a gear pos sensor. Why did OS think that not having one was even an option.

[Piggaz]

5 minutes ago, iruvyouskyrine said:

lmao imagine spending 17k on a box and having to retrofit a gear pos sensor. Why did OS think that not having one was even an option.

Because the box was designed in 1912. It’s a very dated design and apart from the bigger sump they added, hasn’t been “updated/improved” at all. It’s hardly cheap/value for money when you have to muck around with it when you get it to set it up correctly/as a sequential gearbox should be.

[khezz]

Well the way I looked at it is ppg, samsonas 6xd are all around $24k just to buy. Plus clutch so there is another $3k. Ppg I think charge $500 to fit the internals into my case. But there is transit cost from West to East and back again so there is another $600. I have no idea what's involved in fitting a samsonas but let's say it's easy and I'm up for another $500. I am up to $28k to $29k. For $8k to $9k less I can have the OS88 installed with flatshift and it will do the job just fine. It may not be is refined as the others but it will be so much better then the original 5 speed. The change I have left can go towards a very nice interior upgrade.

[reaper]

The problem is the os88 is the weakest of the lot and it's also the harshest to drive. Sure it isn't as loud as a full straight cut box like the Samsonas but the shifts are night and day different.

That to me is worth spending the extra.

[Shoota_77]

2 hours ago, reaper said:

The problem is the os88 is the weakest of the lot and it's also the harshest to drive. Sure it isn't as loud as a full straight cut box like the Samsonas but the shifts are night and day different.

That to me is worth spending the extra.

 

$8000-$9000 difference is MASSIVE.  For me it would be the difference between doing it and not doing it and for @khezz it could well be the same.  Not everyone has a spare $30K that they can just throw at our cars.  Some of us old school GT-R owners (peasants) aren't like the "new trend" of owners that have magic money reserves...

I'm sure you'll absolutely love driving the car with a sequential regardless of what brand it is.

Look forward to seeing vids of the first few pulls at full noise!

[BK]

16 hours ago, khezz said:

$9k less I can have the OS88 installed with flatshift and it will do the job just fine.

That is the question - will it do the job just fine ? We will see I guess

22 minutes ago, Shoota_77 said:

 

$8000-$9000 difference is MASSIVE.  For me it would be the difference between doing it and not doing it and for @khezz it could well be the same.  Not everyone has a spare $30K that they can just throw at our cars.

Absolutely it's a lot of money, but remember he is shooting for 1100+HP with a 7685 or bigger which is huge power. If the OS88 goes bang in a short amount of time that $8000 - $9000 saving is gone into repairing a transmission that was not up to it in the first place.

Now this is all theoretical at this stage so we don't exactly know how it's going to play out - I hope it really does work out. As this build is essentially along the same lines as the top 20 Coota GTR cars you only need to look at what they are running to see what works and what doesn't. Are any of them at this power level using an OS88 without issue ? I don't know but at this power level the transmission is arguably the most important piece of the puzzle.

[Shoota_77]

20 minutes ago, BK said:

That is the question - will it do the job just fine ? We will see I guess

Absolutely it's a lot of money, but remember he is shooting for 1100+HP with a 7685 or bigger which is huge power. If the OS88 goes bang in a short amount of time that $8000 - $9000 saving is gone into repairing a transmission that was not up to it in the first place.

Now this is all theoretical at this stage so we don't exactly know how it's going to play out - I hope it really does work out. As this build is essentially along the same lines as the top 20 Coota GTR cars you only need to look at what they are running to see what works and what doesn't. Are any of them at this power level using an OS88 without issue ? I don't know but at this power level the transmission is arguably the most important piece of the puzzle.

Admittedly that is a big power figure which will go hand in hand with a big torque figure.  Have people been successful holding that sort of power through an OS88?  Wasn't RIPS using one in one of their cars a while back?  EDIT - Just googled and this is an OLLLLLLLDDDDDD article but they were making 1500HP and running 8's in MGAWOT through an OS so obviously it can be done- http://www.speedhunters.com/2013/05/mgawot-2-a-1500hp-gtr-street-car-that-runs-eights/

 

[khezz]

Looking at the Coota records, it seems that OS88 started falling away about 3 years ago. As with all things, better products came on the market. Some still use them and have been using them for years. Mercury R34 held the coota record for years with that box and lived a very hard life very reliably. I really appreciate all the advice. It was the right choice for me. I am not forking out 12-13k for a 20+ year old getrag and the going through the pain of the conversion which will cost thousands more. PPG dog boxes have also gone up in price alot with no real improvement in the product. OS gearsets have a very sketchy reputation and PAR don't seem to do 5 speed anymore. Plus I could not find any cars of similar power running their gears. 

[reaper]

21 hours ago, Shoota_77 said:

 

$8000-$9000 difference is MASSIVE.  For me it would be the difference between doing it and not doing it and for @khezz it could well be the same.  Not everyone has a spare $30K that they can just throw at our cars.  Some of us old school GT-R owners (peasants) aren't like the "new trend" of owners that have magic money reserves...

I'm sure you'll absolutely love driving the car with a sequential regardless of what brand it is.

Look forward to seeing vids of the first few pulls at full noise!

Personally I would save a bit more and wait until I can afford it You save more in the long run rather than doing everything 2 times or 3.

I was just trying to give my first hand experience with it as I have seen/driven all the sequential box options on the market for a gtr. Do with that information what you choose.

 

19 hours ago, khezz said:

Looking at the Coota records, it seems that OS88 started falling away about 3 years ago. As with all things, better products came on the market. Some still use them and have been using them for years. Mercury R34 held the coota record for years with that box and lived a very hard life very reliably. I really appreciate all the advice. It was the right choice for me. I am not forking out 12-13k for a 20+ year old getrag and the going through the pain of the conversion which will cost thousands more. PPG dog boxes have also gone up in price alot with no real improvement in the product. OS gearsets have a very sketchy reputation and PAR don't seem to do 5 speed anymore. Plus I could not find any cars of similar power running their gears. 

The reason you don't see them anymore is because they were breaking and new options came to market about 5 years ago and have continued to grow since.

There was a time a few years ago when there was about 10 of these boxes for sale second hand around the 10-11k mark when everyone jumped ship.

I do hope its reliable for you and does everything you want, it's your car at the end of the day.

[khezz]

Me to mate. Thank you

[khezz]

Going to be ordering a new set of camshafts. Goingbwith Tomei 280/11.5 on both sides. I am not planning on revving the car past 8500rpm so I don't need any more duration and they are the highest should help with spool mid range. Happy to take on any advice people may have.

[iruvyouskyrine]

INB4 everyone saying dont waste money on Tomei and get Kelfords

[khezz]

1 hour ago, iruvyouskyrine said:

INB4 everyone saying dont waste money on Tomei and get Kelfords

I had a look at kelford but there specs seem to be more fo high revving engines and not a huge amount of lift. To go over 11mm lift I need to go to 288 duration. If I was revving my engine to 9500+ or using it purely for racing, that would be ok. I've used 2 sets of tomei cams before and never had an issue. Jun was another consideration with 280/11.65 but can't find many reviews on them.

[WR33KD]

You also know that kelford can do a custom grind for you aswell.

you ask and they make.