Precision Billet Turbos

[BakemonoRicer]

Mick, I think Brett's passion for a responsive all-rounder is long gone...that was pretty clear when he pulled off the v-cam.

let's be realistic here.... we all know Brett loves Roll Racing & once he's spent 60k on the motor & dry sump I'm sure Brett won't want to get munched by a little 450kw+ EVO.

Hence why Brett, I'm suggesting you put a ProMod 88 on, because when you keep losing at roll racing, that's what you'll end up eventually doing. Sure, the car won't be amazing on the street....but at least you'll get to enjoy some solid 'old fella' swinging at roll racing.

 

 

 

[BK]

I hate to say it Brett but I think @Mick_o is smack on here. I'll not be doing v-cam but if my 6466 with the 2.8 does 500kw+ on the 32 with full boost before 5krpm I'll be calling it a day. 

I think Lith already stated the maximum expectations from an RB 6870 above, and that's a v cam 3.2. If you're heart is set on it I say go for it, but I don't think you've really realised the potential of what you already have that's all.

[Lithium]

You know, I read threads like this and wonder why more people don't use nitrous for the special occasions.  Keep your 6466 as a good street turbo, shove a 150shot of nitrous down it's gizzard for roll races against cars which justify it.  A 6466 is more than enough for street and track playing and 6466+150hp or so from nitrous oxide will arguably make the car at least as quick as it would be with a 6870.   

[BK]

3 minutes ago, Lithium said:

You know, I read threads like this and wonder why more people don't use nitrous for the special occasions.  Keep your 6466 as a good street turbo, shove a 150shot of nitrous down it's gizzard for roll races against cars which justify it.  A 6466 is more than enough for street and track playing and 6466+150hp or so from nitrous oxide will arguably make the car at least as quick as it would be with a 6870.   

You are a thinking man for sure 🙇‍♂️

[r32-25t]

I don’t have my heart set on the 6870 at all, in fact I’m still pretty set on the 6466 with the slightly bigger rear on it, doesn’t mean we can’t try and see what else is out there and get some discussion going. 
 

The thing with the vcam is if I decided to go back to it, It is cheaper to sell the step 1 and buy the step 2 or pro then it is to buy the parts to upgrade it anyway 

[BK]

What rear do you have ? I went the 1.00 as it seemed more appropriate for a 2.8 and the smaller ones more used on a 2.6. Maybe bigger again on is preferable.

[Piggaz]

5 minutes ago, r32-25t said:

I don’t have my heart set on the 6870 at all, in fact I’m still pretty set on the 6466 with the slightly bigger rear on it, doesn’t mean we can’t try and see what else is out there and get some discussion going. 
 

The thing with the vcam is if I decided to go back to it, It is cheaper to sell the step 1 and buy the step 2 or pro then it is to buy the parts to upgrade it anyway 

Buy a new sprocket from Subaru and hopefully

kelford produce some decent grinds, not this pensioners turd Japanese junk. Just make sure you have mega piston to valve clearance. 
+1 vote for never binning vcam (emissions cam as some would call it 🙄)

[r32-25t]

2 minutes ago, BK said:

What rear do you have ? I went the 1.00 as it seemed more appropriate for a 2.8 and the smaller ones more used on a 2.6. Maybe bigger again on is preferable.

I’ve currently got the .84 on it and putting the 1.0 on it for the 2.8

[Mick_o]

2 minutes ago, r32-25t said:

I don’t have my heart set on the 6870 at all, in fact I’m still pretty set on the 6466 with the slightly bigger rear on it, doesn’t mean we can’t try and see what else is out there and get some discussion going. 
 

The thing with the vcam is if I decided to go back to it, It is cheaper to sell the step 1 and buy the step 2 or pro then it is to buy the parts to upgrade it anyway 

The thing with the step 2 and or pro is you really don't need the extra 20° of swing they give you and realistically the cams are still average for your application. 10.8mm of lift maximum is more than ample anything over that is just hammering your top end unnecessarily.

30° of swing is more than enough and a custom grind cam will far outweigh the extra swing performance wise & $$$ wise! 

A custom grind intake cam will be thousands of dollars less so I don't know what you're basing that on? 

I think you're bang on in going up a turbine size mate for the extra flow and to help keep the EMAP happy with the extra cubes.

 But f**k those Jun cams off dude lol! Or at least the intake cam 🤣

[BK]

@hattori hanzo Hey Daimian, didn't you swap to a bigger exhaust housing on your 6466 ? Like bigger than 1.00 a/r and made 600kw+ ?

[hattori hanzo]

9 hours ago, BK said:

@hattori hanzo Hey Daimian, didn't you swap to a bigger exhaust housing on your 6466 ? Like bigger than 1.00 a/r and made 600kw+ ?

We had no noticeable difference between .84 and 1.15 however thats because it was choked up on back pressure.

Now we have free flowed everything we should be able to do the same test again

[jet_r31]

12 hours ago, Lithium said:

You know, I read threads like this and wonder why more people don't use nitrous for the special occasions.  Keep your 6466 as a good street turbo, shove a 150shot of nitrous down it's gizzard for roll races against cars which justify it.  A 6466 is more than enough for street and track playing and 6466+150hp or so from nitrous oxide will arguably make the car at least as quick as it would be with a 6870.   

Yeh that one that jez tuned?  That prp put up fb page looks like fun. 

I actually blame it on motive dvd videos and coota.. I actually call it the  "hawkins effect" now... 

Im old and have f**ked up heaps of cars going to large in turbos over last 20+yrs..

Heaps of my mates are late. 20s etc

I try steer them towards keeping vct at alll times'/using long runner intakes if they can.. And midframe turbos on kill for most torque... But no... Everyone want short runner intakes, donkey dick 300 degree cams and 76mm+ turbos... To much motive dvd.. Fine on the runway... From a 60 to 160km roll... No.. Get slaughtered by midframe..but you cant tell them.. Let alone you need a sequential box.. Unless you shift a h pattern so hard you leave the seat everytime to keep it on the boil... And that breaks shit.. 😂 

[jet_r31]

I only just seen these yesterday.. Seems to cheap insurance as its only $60 ish posted ,so i grabbed one

Motion raceworks are the only other supplier i can see doing them with a bevelled edge to hold/flow more leaving the core and a o ring .. But they want more $$ to

[jet_r31]

Rb r33 head... Stock

Rb30 bottom end

256 poncams ... 36psi through a auto trans and slippery converter

6870 ..1.00 housing

Enough for a high 8sec pass

No fancy head or donkey dick cams required.. 

 

Edited May 2, 2021 by jet_r31
WRong

[r32-25t]

I would never go to a large frame turbo! I bought a ba typhoon years ago fitted with a gt42 and I passionately hated it, I ended up selling the big turbo set up and going back to a factory 3582 with the wastegate modified and it transformed the car and made just shy of 400kw on 98 and would blaze tyres in 4th while rolling on throttle. So I’ve been there, done that, bought the shirt and not going back

the only reason I’m even asking about the 6870 is it’s been suggested by a few people and still a mid frame turbo.
 

As I’ve said I’m still pretty set on the 6466 with the bigger rear but getting some decent discussion going that isn’t the usual “my car is missing” threads that have been around lately is good to see again and from the first posts that came after mine I’m far from the only person asking this question 

[ido09s]

Interesting. I have been looking at upgrading the 6766 with 1.0 rear end on the S14. I was thinking of going a 6870 but kinda looks like i should go back to a 6466....

 

[reaper]

I'll just chime in and say don't get too carried away with wanting 900-1000whp with full boost in the 4's or you'll find out the hard way the block can't handle it, billet or not.

Ask me how I know...

[Lithium]

9 minutes ago, reaper said:

I'll just chime in and say don't get too carried away with wanting 900-1000whp with full boost in the 4's or you'll find out the hard way the block can't handle it, billet or not.

Ask me how I know...

Kinda want to know the story behind this, kinda understand why you maybe wouldn't want to tell it.

Do you reckon the cylinder pressures associated with huge boost at those rpm become a general liability - or are you talking about the general power level?   Something I've not seen talked about much, but kinda have discussed with mates on projects we've done (not specifically just for block strength, but usability etc etc) is that the whole "full boost by x..." 

I feel becomes increasingly meaningless as bigger power levels come along, start thinking more about "usable boost"... like how hard it is to get meaningful acceleration to happen.  For quite a while I've been into the idea of tuning the target boost curve to suit the capability of the setup and what its going to be used for - like the MAX power delivery potential of a setup all the way may be less beneficial after a point, but what is cool is if the setup is capable of supporting useful power before 5000rpm while also being able to provide off its nut power >6000rpm is the dream imho.   Not necessarily meaning that if you can hit 40psi by 4500rpm that you should.

 

 

Edited May 2, 2021 by Lithium

[r32-25t]

1 hour ago, Lithium said:

Kinda want to know the story behind this, kinda understand why you maybe wouldn't want to tell it.

Do you reckon the cylinder pressures associated with huge boost at those rpm become a general liability - or are you talking about the general power level?   Something I've not seen talked about much, but kinda have discussed with mates on projects we've done (not specifically just for block strength, but usability etc etc) is that the whole "full boost by x..." 

I feel becomes increasingly meaningless as bigger power levels come along, start thinking more about "usable boost"... like how hard it is to get meaningful acceleration to happen.  For quite a while I've been into the idea of tuning the target boost curve to suit the capability of the setup and what its going to be used for - like the MAX power delivery potential of a setup all the way may be less beneficial after a point, but what is cool is if the setup is capable of supporting useful power before 5000rpm while also being able to provide off its nut power >6000rpm is the dream imho.   Not necessarily meaning that if you can hit 40psi by 4500rpm that you should.

 

 

You know how you all said the ultimate set up would be the 3.2 with the 6870 and vcam that Jez Tuned. That was reapers car and I’ll let him tell the rest of the story if he wants to

[r32-25t]

I also think what happened to his car Might be what happened to mine and part of the reason I removed the vcam