Precision Billet Turbos

[Robzilla32]

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[ohno1]

17 hours ago, r32-25t said:

A .82 rear housing is an open scroll turbine housing you need the .84 twin scroll one on a twin scroll manifold. i have a 6466 .84ts on my stock bottom end 2.6 and mine is all in at 4,100rpm

Nope, thats got nothing to do with it.. ive got an open .82 and im making 30psi at 4500rpm, running 272 10.2mm HKS cams

 

If the setup is only making 18psi @ 5500rpm, I would be looking at dialling in the cams better

 

Edit: 

2860-5s are way shitter in every way compared to the 6466, do not consider buying them, fix the issue with your setup

Edited April 13, 2020 by ohno1

[KiwiRS4T]

Scroll back a few pages to the posts from "feedmyfast" who has a similar setup.

Maybe the problem is your tuner - try turning the boost up to something like 30psi.

[meX]

hey,
thank you for your quick replys. I have to check the rear A/R but if i remember right it was the .84 but I will ask again for that Info. But at least, im not sure if this would change so much on the topic of the spool?

At least the topic from feedmyfast is helpful yes, but he was also running on E85 and i think there is a huge difference between 100 octan and E85 setups? Thats also why I as here for some experiences with 100 Octan. To put a smaller Turbine on the System until it's modified with the 2.8 stroker seems the only possible way i think, but i wont take another turbo which causes that much frustration after investing those amount of money like before.

Further i have to add that my head is also stock, except the head studs and the head gasket. There is also an N1 oil pump installed and a baffle plate in the sump.

Maybe the 6466 is even too big for the actual stock bottom end RB26 but afterwards it may fit with the stroker. In the meantime i want to get out the best what i can, like those twin setups some mates are driving with a very toxic responsivness on the street.
I know the vids from MotiveDVD pretty well and this analysis was also a reason, why i've chosen the single setup instead of a twin before the tuning shop was building the car.

If there are some experiences please let me know. Would be great

So far, have a good time guys!

[Dorifudo]

1 hour ago, meX said:

hey,
thank you for your quick replys. I have to check the rear A/R but if i remember right it was the .84 but I will ask again for that Info. But at least, im not sure if this would change so much on the topic of the spool?

At least the topic from feedmyfast is helpful yes, but he was also running on E85 and i think there is a huge difference between 100 octan and E85 setups? Thats also why I as here for some experiences with 100 Octan. To put a smaller Turbine on the System until it's modified with the 2.8 stroker seems the only possible way i think, but i wont take another turbo which causes that much frustration after investing those amount of money like before.

Further i have to add that my head is also stock, except the head studs and the head gasket. There is also an N1 oil pump installed and a baffle plate in the sump.

Maybe the 6466 is even too big for the actual stock bottom end RB26 but afterwards it may fit with the stroker. In the meantime i want to get out the best what i can, like those twin setups some mates are driving with a very toxic responsivness on the street.
I know the vids from MotiveDVD pretty well and this analysis was also a reason, why i've chosen the single setup instead of a twin before the tuning shop was building the car.

If there are some experiences please let me know. Would be great

So far, have a good time guys!

There is a guy that lives in NZ running a 6466 with a .84ar on a stock bottom end and 4.3 diffs. The response is amazing. Im running at 6466 with a 1.0AR with stock diff ratios and definitely feels "lazier" than his car.

[GTRNUR]

My RB34 with the 6466 Gen1 1.0 opens the gates at 18lb (boost controller off) at 3400 rpm.  I've still got a 1.3 housing here... One day I'll get around to fitting it, with the hopes of stopping the kw drop off around 7500 rpm.

[Dale FZ1]

On 4/12/2020 at 7:48 PM, meX said:

Engine is a Stock RB26 with metal head gasket and stuff (stock bottom end) except HKS 272 degrees camshafts and on that is sitting a PT 6466 CEA Gen2 TwinScroll with a VBand 0.82 A/R outlet (1 Wastegate).

In sum, im actually pretty unhappy with the spool and the driving style. I've got at around 612 HP @18 PSI but the spool at ca. 5,5K rpm is horrible for street drives. The car runs on petrol with 100 octan 

The problem i got is the bad spool and responsivness of the car. It is generally driven on the streets and in the hills, where i need a fast spool and good power band more than everything else and after driving in corners, with this kind of spool, it's feeling like that you shift everytime in a big nowhere.

The first option would be to get another Single from Precision which may fits on the actual Manifold etc. 

I think that it's maybe also possible to just switch the turbo, until the Stroker is done and the head ported. But im still struggling, if this brings the final aim, that i have with the responsivness

The Aim is to get >600 horses at the engine on 100 octans, but the most important is a good responsivness with a good power band.

Friends of mine are driving those 2860-5 and HKS GT-SS Turbos in their r32 gtr's, on the same base and compared to their quick spool, they are completely different cars, but in the street and for some open time track days, it makes even more fun to drive with them.

Welcome to SAU - first time posting!

Firstly - RB26 are not known for strong low-mid range torque.  Your combination of 272 cams and a 6466 that's barely working at 18psi/600hp can't be expected to "wake up" much before 5000rpm. Referring to on-off throttle driving, not what's seen on a dyno sheet.

Secondly - quality of design/fabrication can vary wildly.  Shapes, sizes, angles, merges all play a part in how things work.  Your manifold design, 2 into 1 wastegate pipe merge etc is an unknown.  Was the wastegate pipe divided right up to the valve?  Maybe create a build thread for your car and post up a few pictures to help people see what your car is like.

Thirdly - tuning outcomes can vary wildly.  The engine hardware creates limitations, but so does the tuner's knowledge of how to make something work on the road, as opposed to the dyno.  Something to consider. 

Running 100 octane petrol is no bad thing - your tuner should have capitalised on its knock resistance with an ignition map approaching what might be seen with E85.

Fourthly - final drive gearing definitely alters the way a car feels on road, as per previous comments.  If you can source a set of 4.375 diff gears for your car, the extra rpm in any gear for a given road speed is going to accentuate responsiveness.

Suggestions - install some stock RB26 cams, and spend some dyno time dialling them to what you think you want.  Retain the 6466, talk with your tuner about boost control and what they can do to achieve best spool.  And run another 5psi boost to get an idea of what its capabilities are like.

 

[ohno1]

Some of these responses are inaccurate and misleading.. I feel people are just repeating theories they've read

Once again -- The cams are unlikely to be dialled in correctly

Work from "easy / cheap" to "hard / expensive".. and preferably not go backwards

 

Open inlet 6466 Gen2, 2.6 crank, 272 cams will work together

Might need a couple more pounds boost to get it working more efficiently, but if its coming on @ 5500rpm then there is another issue

I've driven my setup on 21psi before (gate pressure) and it basically comes on the same

Edited April 14, 2020 by ohno1
Extra info

[Dose Pipe Sutututu]

Super lazy way, just +10 advance the intake cam, will wake up the motor in no time.

*** edit, make sure you use all the available tools to accurate dial in the cam within limits, i.e. could be less than 10 degrees of advance before things kiss.

[Mick_o]

On 15/04/2020 at 8:53 AM, ohno1 said:

Open inlet 6466 Gen2, 2.6 crank, 272 cams will work together

Dale is 100% correct its a well proven fact that smaller cams in RB's aid in response. Even going from a stock cam to a type b pon cam will cost you response. Been many track guys that have thrown their poncams in the bin after driving their car, even when the dynosheet looks better it's actually not as good to drive.

My tuner reckons most RB's are over cammed.  (He is no dummy) 272 if you wanna spin it to the moon sure. 272 if you want brapp brapp sic boii idles. But expect it to be soggier in the middle. 

 

[Mick_o]

Skip to 12.05 to further prove my point. 1200hp car that spins to 10500rpm with 264 cams. I wonder why these guys are making their cams smaller??? ?

[BK]

Shhhhh ! I've got 272 Camtech 9.7mm lift cams for sale right now on here, as we have changed back to stock cams in current 2.6 high mount build for the above mentioned reasons.

I won't be able to sell them if you let the secret out ! ?

[Dose Pipe Sutututu]

Dirty plug, I can get Kelford cams at a good price now ?

[KiwiRS4T]

18 hours ago, Mick_o said:

Skip to 12.05 to further prove my point. 1200hp car that spins to 10500rpm with 264 cams. I wonder why these guys are making their cams smaller??? ?

And that's with 30+psi ...so running a biggish turbo at low boost (18 psi) with biggish cams (272) - its going to take a while to get  going.

[Mick_o]

On 18/04/2020 at 8:32 AM, KiwiRS4T said:

And that's with 30+psi ...so running a biggish turbo at low boost (18 psi) with biggish cams (272) - its going to take a while to get  going.

2 biggish turbos actually ?

[Mick_o]

On 12/04/2020 at 8:40 PM, r32-25t said:

A .82 rear housing is an open scroll turbine housing you need the .84 twin scroll one on a twin scroll manifold. i have a 6466 .84ts on my stock bottom end 2.6 and mine is all in at 4,100rpm

I dare say V cam plays the biggest part in that comparison especially when compared to oversized cams lol! 

[KiwiRS4T]

6 minutes ago, Mick_o said:

2 biggish turbos actually ?

No this is a reference to meX who started this particular discussion about his lack of pickup with a single 6466

 

[Mick_o]

Just now, KiwiRS4T said:

No this is a reference to meX who started this particular discussion about his lack of pickup with a single 6466

 

Ahhh yep! 

My apologies ?

[r32-25t]

13 minutes ago, Mick_o said:

I dare say V cam plays the biggest part in that comparison especially when compared to oversized cams lol! 

Still shouldn’t be a 1,400rpm difference 

[Mick_o]

2 hours ago, r32-25t said:

Still shouldn’t be a 1,400rpm difference 

Well between V cam, twin scroll vs open scroll & shitty cam choice I think the writing is on the wall & again proves that big cams hurt response? ?‍♂️