Twin 61mm, A/R .63 too small on a 408?
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Unfortunately Precision doesn't make this model w/ a larger A/R so it's either make em bigger somehow or choose something else altogether. I know it'll come on faster than what I have now but will it be a lightswitch and more important, would it cause too much exhaust backpressure at that A/R?
Any info is appreciated..
Any info is appreciated..
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what type of housings are these?
v-band, 5 or 4 bolt?
on center or tang?
divided or open scroll?
you should have no problem sourcing a couple of .81 a/r housings or larger if you like.
they're out there all over the place, just gotta look around...
v-band, 5 or 4 bolt?
on center or tang?
divided or open scroll?
you should have no problem sourcing a couple of .81 a/r housings or larger if you like.
they're out there all over the place, just gotta look around...
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Unfortunately Precision doesn't make this model w/ a larger A/R so it's either make em bigger somehow or choose something else altogether. I know it'll come on faster than what I have now but will it be a lightswitch and more important, would it cause too much exhaust backpressure at that A/R?
Any info is appreciated..
Any info is appreciated..
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Unfortunately Precision doesn't make this model w/ a larger A/R so it's either make em bigger somehow or choose something else altogether. I know it'll come on faster than what I have now but will it be a lightswitch and more important, would it cause too much exhaust backpressure at that A/R?
Any info is appreciated..
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probaly sort of kinda agree....
i had twin 61mm with .82 a/r single entry on 355 cubes
power started about 4000 rpm.....
dynoed out around 1000 ft /lbs and 770 hp @ 24 psi... at 4000 rpm on stukta dyno
6500 rpm was more ....hehe
so
you got a rocket ship with 408 cubes...
either put some real big gates on it , or get some larger a/r housings
my turbo's where twin gtk 550 's turbonetics ( 61mm )
made max power around 6500 rpm to 7000 ish
std iron heads,
sbc 23 deg
reverse split cam , 256 / 245 @ 114 sep
it had a 10 inch converter ,
and it got pulled to 5700 rpm @ 35 psi boost
keep us updated
cheers
Unfortunately Precision doesn't make this model w/ a larger A/R so it's either make em bigger somehow or choose something else altogether. I know it'll come on faster than what I have now but will it be a lightswitch and more important, would it cause too much exhaust backpressure at that A/R?
Any info is appreciated..
__________________
probaly sort of kinda agree....
i had twin 61mm with .82 a/r single entry on 355 cubes
power started about 4000 rpm.....
dynoed out around 1000 ft /lbs and 770 hp @ 24 psi... at 4000 rpm on stukta dyno
6500 rpm was more ....hehe
so
you got a rocket ship with 408 cubes...
either put some real big gates on it , or get some larger a/r housings
my turbo's where twin gtk 550 's turbonetics ( 61mm )
made max power around 6500 rpm to 7000 ish
std iron heads,
sbc 23 deg
reverse split cam , 256 / 245 @ 114 sep
it had a 10 inch converter ,
and it got pulled to 5700 rpm @ 35 psi boost
keep us updated
cheers
Last edited by crashly; 08-29-2008 at 12:42 AM.
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are you running internally gated turbos?? cause it looks like it from your pic.
this company may have the housings you're looking for.
http://www.atpturbo.com/Merchant2/me...egory_Code=HSG
I'm not a big fan of them, but if you give them a call I'm sure George can find what you're looking for.
these used to be all over the place, if you look around I'm sure you can find them used. Heck, I have two sitting on the shelf in my garage except they are .63 a/r.
depending on the power you're looking to make, and you budget, you might want to consider the less restrictive 4-bolt off center design... see below for comparison.
this company may have the housings you're looking for.
http://www.atpturbo.com/Merchant2/me...egory_Code=HSG
I'm not a big fan of them, but if you give them a call I'm sure George can find what you're looking for.
these used to be all over the place, if you look around I'm sure you can find them used. Heck, I have two sitting on the shelf in my garage except they are .63 a/r.
depending on the power you're looking to make, and you budget, you might want to consider the less restrictive 4-bolt off center design... see below for comparison.
![](http://i9.photobucket.com/albums/a93/4kinboost/turbo_compare.jpg)
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It's actually externally wastegated. I've sent ATP an email so we'll see what they can do. Hopefully, they can do something since it looks like they cater to the Garrett stuff and the unit I'm referring to is a Precision unit.
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Unfortunately Precision doesn't make this model w/ a larger A/R so it's either make em bigger somehow or choose something else altogether. I know it'll come on faster than what I have now but will it be a lightswitch and more important, would it cause too much exhaust backpressure at that A/R?
Any info is appreciated..
Any info is appreciated..
#10
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I dunno if your turbos will go all the way up to 6500 rpms with your motor. but what i do know is twin 61mm is overkill on the street
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#12
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AVB 61mm is the same as what the GT35R turbos are. now i know the APS gusy are running those on LS7s and not having any problems., but they are running a 1.06 housing i think.
could you not go for a 0.83??
Chris.
could you not go for a 0.83??
Chris.
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Precision has confirmed that the T3 5bolt flange only comes in a .63. That's good to know it's similar to the GT35 though.
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Anyone know what the possiblity of boring that .65 housing out to a .8x would be, or has it been done?
Last edited by AVB; 09-01-2008 at 04:11 PM.
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I currently run 66mm T4's on the PTK...
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This is for a setup that'll keep the engine bay cooler on my extreme days I play on roadcourses. Along with lowering and moving weight closer to center, it should be a nice improvement. The goal is to find a setup which has the power come on similarly without losing anything I don't already have now. I didn't think it was going to be too difficult but there isn't an existing kit on the market that keeps brake cooling ducts that I could just bolt on.
Last edited by AVB; 09-02-2008 at 06:43 PM.
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AVB how about having a word with Nick Yoskin. is there nothing you two could come up with??
also thinking about the heat thing, wouldn't smaller turbos cause more heat?? im thinking there will be more backpresure and the turbos will be heating the charge air more than the 66mm will be.
how about running E85?? just thinking you amy beable to run more power and lower boost. This should help reduce under hood temps a little and put less stress on the cooling system....
Could you not get Nick Y to make you some heat shields??
Cheers
Chris.
also thinking about the heat thing, wouldn't smaller turbos cause more heat?? im thinking there will be more backpresure and the turbos will be heating the charge air more than the 66mm will be.
how about running E85?? just thinking you amy beable to run more power and lower boost. This should help reduce under hood temps a little and put less stress on the cooling system....
Could you not get Nick Y to make you some heat shields??
Cheers
Chris.
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AVB how about having a word with Nick Yoskin. is there nothing you two could come up with??
also thinking about the heat thing, wouldn't smaller turbos cause more heat?? im thinking there will be more backpresure and the turbos will be heating the charge air more than the 66mm will be.
how about running E85?? just thinking you amy beable to run more power and lower boost. This should help reduce under hood temps a little and put less stress on the cooling system....
Could you not get Nick Y to make you some heat shields??
Cheers
Chris.
also thinking about the heat thing, wouldn't smaller turbos cause more heat?? im thinking there will be more backpresure and the turbos will be heating the charge air more than the 66mm will be.
how about running E85?? just thinking you amy beable to run more power and lower boost. This should help reduce under hood temps a little and put less stress on the cooling system....
Could you not get Nick Y to make you some heat shields??
Cheers
Chris.
As for E85... since I do DD this thing, doesn't it get crappy gas mileage?
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Nick and I are talking about some ideas and some of his many new options
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Last edited by AVB; 09-03-2008 at 12:55 PM.