Endurance R32 GTS-T build

[smart_garrett]

7 hours ago, sav man said:

I run Penske in my Gtst, but it took a bit of mucking around the get the valving right. 450lb front and 375lb rear works for me.

You can run a 4.6:1 diff out of a sentra that will mask the lag.  But keeping a small turbo and running E85 is really the only way to minimise the lag wihout opening the engine

Unfortunately can’t run e85 as fuel consumption will be way to high as ideally I need to be able to run 2 hour stints on one tank. Do you know of people with that diff ratio? I wonder what kind of speeds you can push out of that with a 20/25 5 speed as there’s some pretty mean straights on a lot of us/Canadian tracks.

[sav man]

14 hours ago, smart_garrett said:

Unfortunately can’t run e85 as fuel consumption will be way to high as ideally I need to be able to run 2 hour stints on one tank. Do you know of people with that diff ratio? I wonder what kind of speeds you can push out of that with a 20/25 5 speed as there’s some pretty mean straights on a lot of us/Canadian tracks.

I've got a 4.6:1 diff in my car.  Depending on wheel size you should be able to get 270-280kph.  With a 4.3:1 at Phillip island I was able to pull 260 kph and that's one of the biggest straights in Aus.  I havn't run with the Phillip Island with the 4.6.

[smart_garrett]

10 hours ago, sav man said:

I've got a 4.6:1 diff in my car.  Depending on wheel size you should be able to get 270-280kph.  With a 4.3:1 at Phillip island I was able to pull 260 kph and that's one of the biggest straights in Aus.  I havn't run with the Phillip Island with the 4.6.

Oh wow that’s fast, I’ve never been able to get this car that fast it really seems to start to struggling in 5th gear around 5k rpms. I’ll definitely look into that ratio then. Do you have kaaz internals or similar or a whole new case/internals?

[sav man]

The 4.6 from the Sentra is pretty much just a bolt in item.  The front bolts have big bushes like a GTR, but I just got some solid bushes turned up so it would mount as standard.  I've got a Nismo Pro 2 way, but you can use the crownwheel and pinion on the standard centre.

5th is too tall to pull, so the shorter diff will help.  E85 also wakes them up a bit (and drops 200c from the EGT), the fuel usage isn't as dramatic as people make out.  Might be worth looking into a GTR fuel tank, they are 73l and plastic, I run one in mine.

[smart_garrett]

9 hours ago, sav man said:

The 4.6 from the Sentra is pretty much just a bolt in item.  The front bolts have big bushes like a GTR, but I just got some solid bushes turned up so it would mount as standard.  I've got a Nismo Pro 2 way, but you can use the crownwheel and pinion on the standard centre.

5th is too tall to pull, so the shorter diff will help.  E85 also wakes them up a bit (and drops 200c from the EGT), the fuel usage isn't as dramatic as people make out.  Might be worth looking into a GTR fuel tank, they are 73l and plastic, I run one in mine.

Thanks for the info on the sentra diff I will definitely be looking more into this. As far as e85 goes I have to do more fuel calcs to make a decision, but I have some worries being as I will be building a sump return catch can which is a necessity for an enduro car. Since this is going in, e85 is generally a stay away when using a sump return even though I would love to use it, but I don't think its safe. I currently have the car mapped on 91 aki (93 but has same octane level due to the high altitude I live at which is about 1850 meters above sea). I have done some testing with 100aki with no ethanol, but since I'm not running very aggressive timing or boost levels, I didn't really need any more knock resistance.

[sav man]

Have a look at putting a crank breather on the car.  I drilled a hole in my block and run a -10 line to my cam cover, takes the pressure out of the sump and allows the oil to drain back through the factory drain holes.  I also did it to a mates car and it went from filling 2x 3l catch cans in a couple of laps to only putting e85 residue in the catch can.

Also worth getting RB26 cam covers (if you can find them), they separate the air/oil heaps better then 20/25

Drain from the catch can to the sump won't work unless you have a pump on the catch can.

[Komdotkom]

I run a 4.375 in mine, works pretty well and I don't have any major lag issues but it's a built motor with a few fancy bits and pieces in it.

My tyre size is 265/35/18 so I could probably go with a 4.6 like Ben but we still do a bit of circuit stuff so need the extra legs.

[smart_garrett]

57 minutes ago, sav man said:

Have a look at putting a crank breather on the car.  I drilled a hole in my block and run a -10 line to my cam cover, takes the pressure out of the sump and allows the oil to drain back through the factory drain holes.  I also did it to a mates car and it went from filling 2x 3l catch cans in a couple of laps to only putting e85 residue in the catch can.

Also worth getting RB26 cam covers (if you can find them), they separate the air/oil heaps better then 20/25

Drain from the catch can to the sump won't work unless you have a pump on the catch can.

Wow, thanks again for all this info I only come from m series bmw motors where people do sumo returns. I can’t get any help over here in the usa with circuit racing rb’s. Can I ask where that hole in the block was drilled? And I assume it just tee’d into the catch system up top from the covers?

[sav man]

I'll dig some photo's up.  But I used the height of the oil return for the RB26 but put it just infront of the cylinder 1 webbing on the hot side.  The line just runs directly to the cam cover to allow the internal baffles to separate any oil and air.  Then the breaters from the cover go to the catch can.

The root cause of most of RB oil problems is there is no external crank breather. so the oil drain holes get used instead, which stops them working as drains.  L-seriers and SR engines have external breathers, so we copied that idea

[smart_garrett]

Hello back with a bit of an update I suppose. Been to 3-4 test days at different tracks talking with all kinds of people that are in the same series as the aimed one. In the U.S, endurance racing is pretty much DOMINATED by anything bmw. e36 4 doors all the way up to brand new m235ir's. After lots of conversation with many teams, I have realized that the r32 is going to be a hard journey to get it to be where the developed e46 330i's are for example. I'm now stuck in a bit of a hole at the moment with what to do. There are several options that I have been running through my head and am maybe looking for a little motivation. 

First option is to sell the car and project outright, which would fund the purchase of an already put together and proven car such as this, and then focus on driving and team logistics.

  

The second option is to continue with the skyline project, which will take more $ and time to get it right, but will probably be a lot cooler in the end if it works out. The catch in this is that I would probably end up putting an s52 bmw engine into it. This would make life easier in the sense of way better reliability, easier drivability, and availability of parts here. If I was to keep developing the skyline, I will be in at least another 20-30k USD to get it going to where I want it to be. 

I'm stuck at the moment with the debate of developing the awesome r32, but struggle for a while to find parts that it needs such as a windshield that is even impossible to find here in the U.S. Or sell it all and move on to a more "bandwagon" car.

 

[sav man]

What mods are allowed in the class?

[smart_garrett]

6 hours ago, sav man said:

What mods are allowed in the class?

Anything. Limitations are a power to weight figure and a power to weight modifier (ie. a sequential box will add a couple decimals onto the power to weight figure). There are different ratios for the 4 classes ranging from 9.0:1 to 13.0:1 I believe. 

[Duncan]

right, so the issue is ability to get response/ area under the power curve from the engine, not peak power then?

it does sounds like some sort of engine swap for more capacity or efficiency will be required to sort that unfortunately. The easiest path with that chassis is a larger capacity bottom end from another RB, RB30 is a potential or possibly RD28 (although that is much heavier).

Bit trickier, perhaps VK45DD or DE from Q45 would be a good choice for torque and economy while still easily making the target power, it appears it can fit OK. Will need a bellhousing to suit and gearbox that ca take the torque. Or something VQ35/7xx would get you there too.

[sav man]

VQ35 make bulk power and torque easy with a turbo.  I''m guessing they are easily avaliable in the US as the 350z was sold there

[smart_garrett]

Here with a long over due update. Where do I start, well I still have the car and have decided to keep developing. I managed to get just about 52 race hours on this rb20det, and this last weekend it finally got a bit tired and found lots of metal in the oil, suspected bearing failure. The chassis is super sorted at this point and just needs a bit of undertray work. The plans have now changed and will include the following. Engine will be a rb25de neo (yes, naturally asperated). This decision was made after lots of thought. I originally wanted to put an bmw s54 in the car, but after the prices have skyrocketed to over 10k for a long block, I have decided against it and to keep the essence of the car with an rb. The plan is to have a header made for it, and I will make a wet carbon intake box, throw in some kelford cams and some springs along with a possible port (haven't thought about this too much yet). Obviously not looking to move into another turbo engine as this is not ideal for having multiple drivers who have experience with n/a cars, not to mention all the problems associated with a turbo. Looking to see if anyone has done similar with a 25de neo, as I cant find too much info on it online, but would love to hear some tips.

[Kinkstaah]

I'm that guy.

My tip would be not to use that engine, the main reason being you'd be happy to get 170whp out of it. Is that really enough for what you want to do? The BMW 3L motors or the 2.5 or the 2.8 would likely perform better and be more available. That said, there's a lot better motors than that in abundance over there in the USA.

_especially_ if you don't need to make it road legal ever.

Signed,
A LS owner.

[smart_garrett]

On 10/11/2021 at 5:22 AM, Kinkstaah said:

I'm that guy.

My tip would be not to use that engine, the main reason being you'd be happy to get 170whp out of it. Is that really enough for what you want to do? The BMW 3L motors or the 2.5 or the 2.8 would likely perform better and be more available. That said, there's a lot better motors than that in abundance over there in the USA.

_especially_ if you don't need to make it road legal ever.

Signed,
A LS owner.

I read online that the neos have just about 200whp from the factory, maybe I read some misinformation. But with some work my thoughts were to maybe get to around 220 whp with it as this would be enough for what I need to do. Again, I’d love an s54 but they’re going for almost 10k usd and that’s a bit crazy I think. Just wanted to try something different I suppose.

[Kinkstaah]

On 10/11/2021 at 11:31 PM, smart_garrett said:

I read online that the neos have just about 200whp from the factory, maybe I read some misinformation. But with some work my thoughts were to maybe get to around 220 whp with it as this would be enough for what I need to do. Again, I’d love an s54 but they’re going for almost 10k usd and that’s a bit crazy I think. Just wanted to try something different I suppose.

It'd need a lot of work. They just... aren't performance engines, not really.

I didn't mean a S54, I meant the M52 variants out there generally put out better results. I'm sure you're painfully aware of E36's with 2.8/3L Hybrid motors making a solid 160-170kw (230whp) in a chassis that is ~1100kg/2400lb in track day specialty trim.

But if you've got the creativity/means/desire to swap an engine I would rebuild the RB20DET to be completely honest, it's a much better option than RB25DE, hands down, absolutely no contest in any scenario. If Engine swaps come into it, the RB25DE of any variant is realistically like the 12th best option.

A VQ as mentioned earlier would be great! But you know what is generally better than that, and fits much better? Lord knows how effective they are on fuel given you said earlier that you're doing 2h races on one tank. This effectively limits power a lot. I wouldn't have thought a RB20DET would even come close to that kind of thriftiness on the track.

 

[smart_garrett]

On 10/11/2021 at 6:44 AM, Kinkstaah said:

It'd need a lot of work. They just... aren't performance engines, not really.

I didn't mean a S54, I meant the M52 variants out there generally put out better results. I'm sure you're painfully aware of E36's with 2.8/3L Hybrid motors making a solid 160-170kw (230whp) in a chassis that is ~1100kg/2400lb in track day specialty trim.

But if you've got the creativity/means/desire to swap an engine I would rebuild the RB20DET to be completely honest, it's a much better option than RB25DE, hands down, absolutely no contest in any scenario. If Engine swaps come into it, the RB25DE of any variant is realistically like the 12th best option.

A VQ as mentioned earlier would be great! But you know what is generally better than that, and fits much better? Lord knows how effective they are on fuel given you said earlier that you're doing 2h races on one tank. This effectively limits power a lot. I wouldn't have thought a RB20DET would even come close to that kind of thriftiness on the track.

 

M series stuff is always an option… but at that point I might as well have an e36/46. Our 46 that we race has an m54 in it, but man they really struggle to get much race hours out of them before they need full overhauls. There’s a guy local to me with a vq in his s14 that races it, it’s an option but I’ve never really been a fan of the engine to be honest. I’d love to stick with a Nissan straight 6 because if not, a k20/24 would probably be the next easiest option. Honestly, if the engine can last 50 race hours and can put out 220hp n/a then sign me up, it’s all you need to fit into the right class for what I’m doing.

[Komdotkom]

VQ37 and six speed. Cheap in the states and with a set of JWT cams will easily eclipse and S54 in power, reliability and torque. Not to mention you get rid of front axle weight and gain better ratios in the gearbox at the same time.

Add a turbo and 350kw reliably is very easy to achieve without any other supporting mods.