DIY Turbo Discussion greddy on a 1.8? homebrew kit?

LOWERING boost pressure

Thread Tools
 
Search this Thread
 
Old 01-07-2016, 05:29 PM
  #21  
Elite Member
iTrader: (6)
 
ryansmoneypit's Avatar
 
Join Date: Feb 2013
Location: A cave in Va
Posts: 3,395
Total Cats: 456
Default

Wanting only 3 or 4 psi, you should just put together a good NA package. Enjoy 145-165hp and sweet torque. Your wallet will thank you.

The funny thing about turbo, is that not only does it ingest air, but also copious amounts of hundred dollar bills. Hundreds of them. A good NA set up is less likely to do so.
ryansmoneypit is offline  
Old 01-07-2016, 05:32 PM
  #22  
Moderator
iTrader: (1)
 
Girz0r's Avatar
 
Join Date: Jun 2014
Location: Austin, TX
Posts: 3,033
Total Cats: 324
Default

Originally Posted by acedeuce802
Save up, do it right from the get go.
MKTRUBO.COM From our very own shuiend. He'll set you up for EVERYTHING, you just tune. Or give no phucs and run a doodoo II box with the 7ish psi you're seeking.
Girz0r is offline  
Old 01-07-2016, 06:20 PM
  #23  
Junior Member
Thread Starter
iTrader: (1)
 
squeegee's Avatar
 
Join Date: Aug 2011
Posts: 88
Total Cats: 7
Default

Originally Posted by ryansmoneypit
Wanting only 3 or 4 psi, you should just put together a good NA package. Enjoy 145-165hp and sweet torque. Your wallet will thank you.

The funny thing about turbo, is that not only does it ingest air, but also copious amounts of hundred dollar bills. Hundreds of them. A good NA set up is less likely to do so.
I may be happy with 3-4 psi, but I'd be REALLY happy with 220 hp. 10lbs/hp seems like an attainable goal. I want to make enough power to spin the wheels from mashing the gas in first for sure.

Part of the reason I want to rush things is that I have access to a really nice TIG welder through college. I have a crazy manifold design I'm itching to build
squeegee is offline  
Old 01-07-2016, 06:36 PM
  #24  
Elite Member
iTrader: (6)
 
ryansmoneypit's Avatar
 
Join Date: Feb 2013
Location: A cave in Va
Posts: 3,395
Total Cats: 456
Default

Then get out your wallet, 2 grand is about 3 away from your idea. I promise.

I just realized that you want to do this with a 1.6, and no intercooler. You have no idea what you're getting into.
ryansmoneypit is offline  
Old 01-07-2016, 06:56 PM
  #25  
Senior Member
iTrader: (1)
 
acedeuce802's Avatar
 
Join Date: Dec 2010
Location: Farmington Hills, MI
Posts: 1,218
Total Cats: 175
Default

Originally Posted by squeegee
I may be happy with 3-4 psi, but I'd be REALLY happy with 220 hp. 10lbs/hp seems like an attainable goal. I want to make enough power to spin the wheels from mashing the gas in first for sure.

Part of the reason I want to rush things is that I have access to a really nice TIG welder through college. I have a crazy manifold design I'm itching to build
Pull header -> Hold turbo -> Make fixture -> Reinstall header -> Make awesome manifold -> graduate and make monies -> Piece together awesome parts -> Win

Or do what I do, keep in touch with people back at college so you can use their machines.
acedeuce802 is offline  
Old 01-07-2016, 07:09 PM
  #26  
Junior Member
Thread Starter
iTrader: (1)
 
squeegee's Avatar
 
Join Date: Aug 2011
Posts: 88
Total Cats: 7
Default

5k for the 220hp Miata or for 4psi? I'm not afraid to spend that much in the end. That's a lot up front, which is why I'm trying so hard to do baby steps. I've been following your build thread a while, and I'm not going THAT hardcore. At least not yet. I'm fine with putting an autizone breather on my PCV for now.
squeegee is offline  
Old 01-07-2016, 07:13 PM
  #27  
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
Default

5k is the general noobie basic turbo build*. You can do it for less. But it requires knowledge and time.

*that isn't a piece of ebay junk.

It adds up quick

aidandj is offline  
Old 01-07-2016, 07:18 PM
  #28  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

if you can't afford to modify a miata correctly, then you should get a job.
if you have a job, well then you should go back to school so you can get a job better than mcdonalds.

very few cars are cheaper to modify than miata's
/serious
18psi is offline  
Old 01-07-2016, 07:31 PM
  #29  
Junior Member
Thread Starter
iTrader: (1)
 
squeegee's Avatar
 
Join Date: Aug 2011
Posts: 88
Total Cats: 7
Default

Originally Posted by acedeuce802
Pull header -> Hold turbo -> Make fixture -> Reinstall header -> Make awesome manifold -> graduate and make monies -> Piece together awesome parts -> Win

Or do what I do, keep in touch with people back at college so you can use their machines.
For sure. One guy on the formula electric team says he's going to save up and buy a CNC mill. If he buys tools half as cool as that, he'll still be a good guy to know. We need a student ID to use the equipment so I may have to seduce someone to keep that going.

That's basically the plan though, except accounting for some extra cash from internships.
I'll be pulling off the headers to replace them soon anyway. I'll see if I can get my hands on a T25 and find a future home for it
squeegee is offline  
Old 01-07-2016, 07:39 PM
  #30  
mkturbo.com
iTrader: (24)
 
shuiend's Avatar
 
Join Date: May 2006
Location: Charleston SC
Posts: 15,177
Total Cats: 1,681
Default

Originally Posted by squeegee
For sure. One guy on the formula electric team says he's going to save up and buy a CNC mill. If he buys tools half as cool as that, he'll still be a good guy to know. We need a student ID to use the equipment so I may have to seduce someone to keep that going.

That's basically the plan though, except accounting for some extra cash from internships.
I'll be pulling off the headers to replace them soon anyway. I'll see if I can get my hands on a T25 and find a future home for it
Wait why on earth are you replacing your header if you want to go turbo. The proper way to boost your car is as follows. Anything besides this route and we will all ridicule you.

1. Install a MS and a wideband. Learn to tune your car stock.
2. Install a 1.8 motor, install stronger clutch at the same time. FM1 or ACT are the only ones you should consider.
3. Install a 1.8 rear end.
4. Install larger injectors and retune fuel.
5. Install turbo setup.
6. Boost happily ever after.
shuiend is offline  
Old 01-07-2016, 07:42 PM
  #31  
Senior Member
iTrader: (1)
 
acedeuce802's Avatar
 
Join Date: Dec 2010
Location: Farmington Hills, MI
Posts: 1,218
Total Cats: 175
Default

Originally Posted by squeegee
formula electric team
What school do you go to?
acedeuce802 is offline  
Old 01-07-2016, 07:52 PM
  #32  
Junior Member
Thread Starter
iTrader: (1)
 
squeegee's Avatar
 
Join Date: Aug 2011
Posts: 88
Total Cats: 7
Default

Originally Posted by shuiend
Wait why on earth are you replacing your header if you want to go turbo. The proper way to boost your car is as follows. Anything besides this route and we will all ridicule you.

1. Install a MS and a wideband. Learn to tune your car stock.
2. Install a 1.8 motor, install stronger clutch at the same time. FM1 or ACT are the only ones you should consider.
3. Install a 1.8 rear end.
4. Install larger injectors and retune fuel.
5. Install turbo setup.
6. Boost happily ever after.
I have a crack in my headers down in the collector, so I don't trust my wideband. I found some stock pipes for much cheaper than eBay.

I'm already getting a lot of heat for trying to turbo too soon, I'll get banned for starting a flamrear if I start advocating why I'm staying 1.6 lol
squeegee is offline  
Old 01-07-2016, 07:57 PM
  #33  
mkturbo.com
iTrader: (24)
 
shuiend's Avatar
 
Join Date: May 2006
Location: Charleston SC
Posts: 15,177
Total Cats: 1,681
Default

Originally Posted by squeegee
I have a crack in my headers down in the collector, so I don't trust my wideband. I found some stock pipes for much cheaper than eBay.

I'm already getting a lot of heat for trying to turbo too soon, I'll get banned for starting a flamrear if I start advocating why I'm staying 1.6 lol
I am almost sure you could post a WTB add on here and get a stock 1.6 header for probably not more then the cost of shipping, but you claim to have access to a welder. ******* weld the crack and leave the stock header there. You make it seem like you are on a tight budget, but then want to go spend money on wasteful things. That is why we are flaming you.
shuiend is offline  
Old 01-07-2016, 07:58 PM
  #34  
Junior Member
Thread Starter
iTrader: (1)
 
squeegee's Avatar
 
Join Date: Aug 2011
Posts: 88
Total Cats: 7
Default

Originally Posted by acedeuce802
What school do you go to?
Missouri S&T. Id be surprised if you've heard of us, but a pic of the combustion team's car was in a Jalopnik article recently, so maybe you have
squeegee is offline  
Old 01-07-2016, 08:02 PM
  #35  
Senior Member
iTrader: (1)
 
acedeuce802's Avatar
 
Join Date: Dec 2010
Location: Farmington Hills, MI
Posts: 1,218
Total Cats: 175
Default

Originally Posted by squeegee
Missouri S&T. Id be surprised if you've heard of us, but a pic of the combustion team's car was in a Jalopnik article recently, so maybe you have
I know plenty about you guys. I just graduated from Kettering and was our lead suspension designer for a year and Chief Engineer for two years.
acedeuce802 is offline  
Old 01-07-2016, 08:14 PM
  #36  
Senior Member
iTrader: (8)
 
cyotani's Avatar
 
Join Date: Jan 2012
Location: Azusa, CA
Posts: 1,407
Total Cats: 116
Default

Originally Posted by squeegee
I've searched the forum and there's lots of info on raising boost pressure, but how about getting 3-4 psi out of a SR20 T25?

I know I'll get some flak for doing things a bit backwards, but I'd like to start with low enough boost where I won't need an intercooler, clutch or diff (It's a 1.6) right off the bat to get things sorted before having to upgrade.

Seems to me that you'd also get a great tune if you dialed in 4 psi, then all the cells for 6, 8, etc.

Is it possible that the stock 7psi is mild enough?
Wire the wastegate wide open. Do a pull to redline (3rd or 4th if possible). The max PSI you see is purely due to boost creep and has nothing at all to do with the wastegate actuator itself (your wastegate port is choked and not allowing enough exhaust to bypass the turbo to maintain your target boost level).

If you're over your 4psi target you need to do porting work to the turbo to allow more airflow through the wastgate path. Repeat until you don't exceed target boost with WG tied open.

Then select an appropriate actuator. The lowest I've seen from garret is a 5.4psi I think. If you want to later raise boost use an EBC plus the megasquirt boost control.
cyotani is offline  
Old 01-07-2016, 08:59 PM
  #37  
Junior Member
Thread Starter
iTrader: (1)
 
squeegee's Avatar
 
Join Date: Aug 2011
Posts: 88
Total Cats: 7
Default

Originally Posted by cyotani
Wire the wastegate wide open. Do a pull to redline (3rd or 4th if possible). The max PSI you see is purely due to boost creep and has nothing at all to do with the wastegate actuator itself (your wastegate port is choked and not allowing enough exhaust to bypass the turbo to maintain your target boost level).

If you're over your 4psi target you need to do porting work to the turbo to allow more airflow through the wastgate path. Repeat until you don't exceed target boost with WG tied open.

Then select an appropriate actuator. The lowest I've seen from garret is a 5.4psi I think. If you want to later raise boost use an EBC plus the megasquirt boost control.
Thanks, that makes a lot of sense.

It might help your faith in humanity to know that the crack was right in the crotch of the collector, so fitting the tungsten and rod in there would be a trick.

Hey ace, did your leadership experience on the team earn you big points with the job recruiters?
squeegee is offline  
Old 01-07-2016, 09:16 PM
  #38  
Senior Member
iTrader: (1)
 
acedeuce802's Avatar
 
Join Date: Dec 2010
Location: Farmington Hills, MI
Posts: 1,218
Total Cats: 175
Default

Originally Posted by squeegee

Hey ace, did your leadership experience on the team earn you big points with the job recruiters?
You betcha. I'm now working my dream job at Pratt & Miller.
acedeuce802 is offline  
Old 01-07-2016, 10:31 PM
  #39  
Elite Member
iTrader: (6)
 
ryansmoneypit's Avatar
 
Join Date: Feb 2013
Location: A cave in Va
Posts: 3,395
Total Cats: 456
Default

[QUOTE=squeegee;1297627]Thanks, that makes a lot of sense.

It might help your faith in humanity to know that the crack was right in the crotch of the collector, so fitting the tungsten and rod in there would be a trick.

You either mig it, or hang the tungsten out and add a bunch of gas. Either way, someone had to weld it originally.

Thanks for your comments on my build. It got way out of control. Total accident. Be careful, boost is a drug.
ryansmoneypit is offline  
Old 01-07-2016, 10:32 PM
  #40  
Elite Member
iTrader: (6)
 
ryansmoneypit's Avatar
 
Join Date: Feb 2013
Location: A cave in Va
Posts: 3,395
Total Cats: 456
Default

I don't even think you are getting flamed at all. This site just tries hard to prod people into making good decisions.
ryansmoneypit is offline  


Quick Reply: LOWERING boost pressure



All times are GMT -4. The time now is 06:40 PM.