DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Precision Turbos?

Thread Tools
 
Search this Thread
 
Old 01-10-2012, 12:03 PM
  #21  
Junior Member
iTrader: (1)
 
1slowna's Avatar
 
Join Date: Oct 2008
Location: Palm Harbor FL
Posts: 328
Total Cats: 4
Default

One of our customers has the world record 2v mod motor mustang, it had an 88mm non ball bearing precision on it and it ran 8.85. He went to an 88mm ball bearing and it went a 8.66. But more importantly he has a back pressure sensor in the collector which showed a huge drop in back pressure even with the same size A/R just going from journal to ball bearing, with billet wheel and he was able to give it more timing without detonation as a result.
400whp i can imagine would be extremely difficult to reach with a t2 frame turbo <Edit> Without e85.
1slowna is offline  
Old 01-11-2012, 01:26 PM
  #22  
Elite Member
iTrader: (2)
 
Faeflora's Avatar
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,682
Total Cats: 130
Default

Originally Posted by 1slowna
One of our customers has the world record 2v mod motor mustang, it had an 88mm non ball bearing precision on it and it ran 8.85. He went to an 88mm ball bearing and it went a 8.66. But more importantly he has a back pressure sensor in the collector which showed a huge drop in back pressure even with the same size A/R just going from journal to ball bearing, with billet wheel and he was able to give it more timing without detonation as a result.
400whp i can imagine would be extremely difficult to reach with a t2 frame turbo <Edit> Without e85.
Interesting. Thanks for the info!
Faeflora is offline  
Old 01-11-2012, 01:50 PM
  #23  
Elite Member
iTrader: (9)
 
TurboTim's Avatar
 
Join Date: Jun 2006
Location: Chesterfield, NJ
Posts: 6,892
Total Cats: 399
Default

I noticed that between yesterday (when Precision got back to me recommending the PT5858 CEA for my 2.5) and last week, they went thru and deleted quite a few turbos from their website's listing, especially in the "450-600" category. I am looking forward to seeing what they come out with in the T2 size range and their "3-4 months out" stainless vband housings (their current vband housings are not stainless).
TurboTim is offline  
Old 01-11-2012, 04:12 PM
  #24  
I'm Miserable!
 
SupraTim's Avatar
 
Join Date: Jan 2012
Posts: 16
Total Cats: 0
Default

Originally Posted by Faeflora
I'm not sure that your idea about the turbine speed affecting backpressure that much is correct. A/R makes sense.

Data point- it was very hard for me to hit 400hp with my GT30 and log manifold.
Your going to need a tubular manifold to go further. a GT30 ( 57mm compressor wheel) can easily reach 400 horsepower. What size backhousing are you using? I assume 0.63 AR? You can try jumping to the .81 to bump the top end power, but the money is better spent on a new manifold id think. Last turbine housing I bought by itself was almost 400 bucks lol. Alot of money for a small change.

I made 374 WHP on my honda (1.8) @ only 11.5 psi using my GT3076 with a 0.63 backhousing on a tubular manifold.

Last edited by SupraTim; 01-11-2012 at 04:32 PM.
SupraTim is offline  
Old 01-11-2012, 04:27 PM
  #25  
Elite Member
iTrader: (9)
 
TurboTim's Avatar
 
Join Date: Jun 2006
Location: Chesterfield, NJ
Posts: 6,892
Total Cats: 399
Default

Originally Posted by SupraTim
Your going to need a tubular manifold to go further. a GT30 ( 57mm compressor wheel) can easily reach 400 horsepower. What size backhousing are you using? I assume 0.63 AR? You can try jumping to the .81 to bump the top end power, but the money is better spent on a new manifold id think. Last turbine housing I bought by itself was almost 400 bucks lol. Alot of money for a small change.
Search for Failfloral's current 100 page build thread. He dumped that old setup a while ago; he's currently running one of the slickest equal length manifolds and a gigantic twinscroll Borg with a quickspool valve. And he knocks while cruising.

Your information however is still valid, don't get me wrong.
TurboTim is offline  
Old 01-11-2012, 05:24 PM
  #26  
Elite Member
iTrader: (2)
 
Faeflora's Avatar
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,682
Total Cats: 130
Default

Originally Posted by SupraTim
I made 374 WHP on my honda (1.8) @ only 11.5 psi using my GT3076 with a 0.63 backhousing on a tubular manifold.
Honda 1.8 =/= Mazda 1.8 :( :( :(

Originally Posted by TurboTim
And he knocks while cruising.
Cheap shot!
Faeflora is offline  
Old 01-11-2012, 05:39 PM
  #27  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

yes Honda 1.8 =/////////////////////////////////////=mazda 1.8
18psi is offline  
Old 01-11-2012, 05:59 PM
  #28  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

Supratim, what 's your hold?
hustler is offline  
Old 01-11-2012, 11:15 PM
  #29  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

Originally Posted by 1slowna
At least this is my understanding, correct if incorrect.
Consider this your correction - it's completely wrong. When you hydrolock, it is absolutely a massive downward force - it is the force of the (essentially) incompressible water acting against the inertia of the piston. Decreasing the backpressure in the exhaust manifold by a few PSI (even 10+psi in extreme cases) is like rearranging the deck chairs on the Titanic when you compare it to the hundreds of PSI the engine experiences during the combustion phase.

There is nothing magical about the people making huge power on factory motors - they are either lucky, not running the motor very hard, or not telling us about it when it finally explodes.
Savington is offline  
Old 01-12-2012, 12:59 AM
  #30  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

Originally Posted by 1slowna
Its a concept the honda guys got figured out but big turbos do not work well on road courses so most people building a setup for their miata will go with the tiny turbo and cast manifold which greatly limits the power capabilities of the stock motor IMO. Just think about how a rod bends when you hydrolock, the rod bends on its way up, not on its way down due to a massive thrust downward. At least this is my understanding, correct if incorrect.
Okay dude, thanks. We have absolutely nothing in common with Honda engines...nothing.
hustler is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
04-12-2021 04:21 PM
Rick02R
WTB
3
01-03-2016 07:18 PM
tazswing
Race Prep
20
10-03-2015 11:04 AM
cale saurage
DIY Turbo Discussion
16
10-01-2015 11:25 AM



Quick Reply: Precision Turbos?



All times are GMT -4. The time now is 06:41 AM.