Precision Billet Turbos

[PJ.]

The 6466 is a fair wack bigger (195hp rated), I doubt you would be getting that for nothing

Exactly.

[donut_kng]

Pretty much my dilemma as I was saying on the last page, going off the dyno sheet on the 3.4L there isn't much in it and the top end gains are great.

From going by there website the 6262 was the first of that sort of series then they did the 6266 which is a touch bigger, then the 6766 which is bigger then a To4z then recently the 6466 which sits midway between 6266 and 6766.

And yeah I highly doubt you would notice the 600-700rpm difference (as quoted by a precision rep i spoke to) between a 6262 and a 6466. You literally wouldn't pick it by driving it I think you would only notice on a dyno graph as above considering how long it takes to jump 500rpm at the 4000rpmk mark on even a stock RB

[SimonR32]

And yeah I highly doubt you would notice the 600-700rpm difference (as quoted by a precision rep i spoke to) between a 6262 and a 6466. You literally wouldn't pick it by driving it I think you would only notice on a dyno graph as above considering how long it takes to jump 500rpm at the 4000rpmk mark on even a stock RB

Are you joking? 600-700rpm is a huge difference. That's about the difference between the T88 that was on my car and the 6262 I now have.

The T88 was horrible and I mean horrible on the street and even worse at the track while the 6262 is a great little zippy thing.

[Lithium]

Well my 6262 is better than my old T04Z but not the miracle that some would lead you to believe. The 6466 is a fair wack bigger (195hp rated), I doubt you would be getting that for nothing

That's why I thought I'd ask, people have claimed that the PT6262 spools better than the GT3582R which sounds unlikely but who knows. The PT6466 is not far different in measurements to the T04Z and there is no lb/min rating for them - though Precision rate them at 900hp. Does that mean they can be used in place of a T51R Kai on a pump gas setup for someone looking for a bit more power with the same or less lag? It seems unlikely to me.... there isn't even any reason for me to have confidence that they'd make more on pump gas than a T04Z.

I'm trying to determine the place of the larger Precision turbos when huge boost and E85 isn't involved.

[Frosty]

From what i've read i'd say the 6466 would be about 500-800rpm later than the 6262?

thats alot of RPM to be wasted

[Frosty]

Are you joking? 600-700rpm is a huge difference. That's about the difference between the T88 that was on my car and the 6262 I now have.

The T88 was horrible and I mean horrible on the street and even worse at the track while the 6262 is a great little zippy thing.

the wheel sizes im camparison are a huge difference between the too aswell which is why i find it hard to believe that they are rating it that much laggier between the 62 and 64mm turbines

[PJ.]

That's why I thought I'd ask, people have claimed that the PT6262 spools better than the GT3582R which sounds unlikely but who knows. The PT6466 is not far different in measurements to the T04Z and there is no lb/min rating for them - though Precision rate them at 900hp. Does that mean they can be used in place of a T51R Kai on a pump gas setup for someone looking for a bit more power with the same or less lag? It seems unlikely to me.... there isn't even any reason for me to have confidence that they'd make more on pump gas than a T04Z.

I'm trying to determine the place of the larger Precision turbos when huge boost and E85 isn't involved.

From my experience with my own engine, a certain boost pressure = very similar power level provided the turbo is still within its capabilities. When a turbo start to roll over of course the power gains decrease per psi. As you'd know pump fuel and 900hp are a mismatch (on a small engine anyway), as you will never be able to put the boost in that is required to get it in the zone.

I would certainly place my bets in saying that a 6466 will outspool a T51 donkey (sorry to all my friends who I have offended in saying that )

The test that Sound performance is a good example how different the 3 Precisions react even though they have identical exhaust wheels.

[Lithium]

From my experience with my own engine, a certain boost pressure = very similar power level provided the turbo is still within its capabilities. When a turbo start to roll over of course the power gains decrease per psi. As you'd know pump fuel and 900hp are a mismatch (on a small engine anyway), as you will never be able to put the boost in that is required to get it in the zone.

Yep, same findings here too - well except for 900hp on pump fuel, I know a few mad men who have managed 900hp (flywheel estimated at least) on pump gas on RBs. Big turbos, lots of rpm and head porting involved of course.

I would certainly place my bets in saying that a 6466 will outspool a T51 donkey (sorry to all my friends who I have offended in saying that )

Hahahaha yeah you would REALLY hope it would outspool a T51R, though I would be extremely surprised if you could squeeze the same pump gas numbers out of an engine capable of it from a 6466 as a T51R.... and to be fair, would be interesting to see if the peak power numbers on race fuel would be comparable too. I wonder how those power ratings were determined...

The test that Sound performance is a good example how different the 3 Precisions react even though they have identical exhaust wheels.

Some of these tests make me really wish I had a dyno. A lot of these tests people refuse to touch timing etc to keep things equal, and I honestly haven't done enough first hand dyno tuning with like setups to ascertain whether this is a fair way of comparing or not. Will optimal timing be the same at the same load and rpm for every different turbo setup?

[GTScotT]

Some of these tests make me really wish I had a dyno. A lot of these tests people refuse to touch timing etc to keep things equal, and I honestly haven't done enough first hand dyno tuning with like setups to ascertain whether this is a fair way of comparing or not. Will optimal timing be the same at the same load and rpm for every different turbo setup?

Ive also always been wary of bolt on bolt off tests that crop up. Surely charge temp and turbine efficiency alone would leave a few degrees in the lurch between models.. Otherwise what is the point of spending an absolute packet on tuning? Time to jet up our cabys and change the chip in our MSD.

Get yourself a dyno Lith Once you have a place to sit and tune which belongs to you the customers will start lining up.

[PJ.]

Here are some more results from this Saturday on the dyno. We were aiming for 35psi on the next hit, unfortunately the idle speed control screw of all things decided to unwind itself. It was already 9pm when we sorted it out so had to cut it short, but I am very confident in saying that we would have seen 1150whp.

Pretty amazing how linear the power curve is since it is making drag engine power. Rev limit is set to 9500rpm.

[jet_r31]

Very nice, sounds awesome to

cheers

darren

[SimonR32]

Went for a drive yesterday (to get it licenced) and did some 4th gear flat road pulls from around 3000rpm, getting 1 bar at 3700-3800rpm which is probably a few hundred rpm better than my old GTR with a T04Z with similar top end power capability. Makes for a savage car on the road, pulls long and hard through the gears and is an absolute bullet.

Going to go back on the dyno after I sort out a second 044 and run it up again holding 1.6bar through the revs, should go 650hp (485kw) fairly easily by the looks

[Frosty]

Here are some more results from this Saturday on the dyno. We were aiming for 35psi on the next hit, unfortunately the idle speed control screw of all things decided to unwind itself. It was already 9pm when we sorted it out so had to cut it short, but I am very confident in saying that we would have seen 1150whp.

Pretty amazing how linear the power curve is since it is making drag engine power. Rev limit is set to 9500rpm.

nice...

can you post a sheet? couldnt really see the figures prop.

where was it coming on boost?

[rbjunkie]

SimonR32, keen as to see your results!!

[jet_r31]

Thats a nice looking R32 GTR simon!, i love those rims on 32's

cheers

darren

[eXquiSit]

guys, i seem to be blowing out a bit of blue smoke on hard acceleration and shortly after

just wondering what could cause this

i am running -4 feed as per precision's recommendations and a hardline drain to -12 hose to the block

i thought precisions had in built restrictors or do i need to put one in??

[GTScotT]

Is yours BB or JB? And are you certain its oil smoke?

Check cooler plumbing and plugs for signs of oil leaking from the compressor side. Most leaky PT threads I have seen are comp side and the leak can be seen on idle with the pipes off.

[eXquiSit]

it is BB unit

i will check the pipes in the arvo

=)

[GTScotT]

For a BB I had read in the past they want a -3 line. I may be wrong though, bloody delicate things.

[SiR_RB]

Where's the best and quickest place I can get a precision 6266cea journal From?

Powertune only have the ball bearing in stock