home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > performance & modifications

Reply
 
Thread Tools Display Modes
Old 11-13-2021, 02:25 PM   #1
740Lover
Newbie
 
Join Date: Nov 2021
Question How to push 20psi out of a 15g???

Hi! I have a ‘92 740+T with your standard 15g swap running on about 5psi to keep things safe. Everything is pretty much stock excluding a 2” exhaust and aftermarket air filter. I’d like to eventually crank things up a bit but want to do so in a reliable manner. Im already planning on getting ARP head studs and a Cometic metal head gasket to keep things nice n tight but I’m curious what sort of injectors I should run? I was considering running some Deatschwerks 650cc injectors but, this being my first turbocharged car, I’m not sure how much boost 650cc’s can handle. I read that a stock b230ft with a 13c turbo can reliably run 12-13psi so I’m not necessarily afraid of pushing my engine with this 15g but I’d rather not accidentally detonate my first 740. Since this will still be a daily driver I’m not trying to run it on 20psi all the time; but I’d like to be able to crank it up reliably when wanted. Also how much can the stock fuel rail handle? Or should I just upgrade that too while I’m at it..? If there’s anything else I’m missing please don’t be afraid to let me know! This is my still my first year owning this car and I’m trying to learn as much as possible and do this in the most correct way that I can. Thanks !

Last edited by 740Lover; 11-13-2021 at 03:09 PM.. Reason: Forgot to mention fuel rail.
740Lover is offline   Reply With Quote
Old 11-13-2021, 02:45 PM   #2
sbabbs
Board Member
 
sbabbs's Avatar
 
Join Date: Dec 2006
Location: Rushing Lane, Scappoose, OR
Default

I did it with E85 gasoline and 750cc injectors and 3 inch amm and straight pipe out the side and NPR intercooler and A cam and fuel and ignition chips. 5 speed manual trans 3.31 ratio rear third gear pull.





The thing about injectors and LH 2.4 is the injector size has to match the AMM size. 550cc works good with 3 inch AMM and gasoline. 750cc works good with 3 inch AMM and E85. Other then that you can adjust the injector constants in the fuel bin instead if you can or can buy a custom chip. So your 650cc injectors would be way to rich or to much fuel as they say. Something else to consider is if you run E85 you can overfuel it and you won't loose power like you would with gasoline.

Simon
__________________
1988 245 White slicktop M47 Wagon! 93 b230f. LH 2.4 STS flat flywheel.
1990 745 B230FT Getrag JohnV flywheel 240mm clutch 13c A-cam 3.54 G80 548K
1991 740SE B230FT NPR Strut braces IPD bar A cam 550cc EV14's. 3.73 G80 M90 to put in.
1995 940 White racing wagoon. 13c m90 to put in
sbabbs is offline   Reply With Quote
Old 11-13-2021, 02:47 PM   #3
James M
Bored member
 
James M's Avatar
 
Join Date: May 2017
Location: Chico, CA
Default

Quote:
Originally Posted by 740Lover View Post
Hi! I have a ‘92 740+T with your standard 15g swap running on about 5psi to keep things safe. Everything is pretty much stock excluding a 2” exhaust and aftermarket air filter. I’d like to eventually crank things up a bit but want to do so in a reliable manner. Im already planning on getting ARP head studs and a Cometic metal head gasket to keep things nice n tight but I’m curious what sort of injectors I should run? I was considering running some Deatschwerks 650cc injectors but, this being my first turbocharged car, I’m not sure how much boost 650cc’s can handle. I read that a stock b230ft with a 13c turbo can reliably run 12-13psi so I’m not necessarily afraid of pushing my engine with this 15g but I’d rather not accidentally detonate my first 740. Since this will still be a daily driver I’m not trying to run it on 20psi all the time; but I’d like to be able to crank it up reliably when wanted. If there’s anything else I’m missing please don’t be afraid to let me know! This is my still my first year owning this car and I’m trying to learn as much as possible and do this in the most correct way that I can. Thanks !
Redblocks don't have the headgasket issues you'll find with a lot of motors *cough cough, m20* you don't need headstuds or MLS gaskets for a 15g.

As far as learning what supporting mods to do give turbobricks a search, there is decades of info on here that can both directly answer the question and inform you of thing you never would have thought of.
James M is offline   Reply With Quote
Old 11-13-2021, 03:15 PM   #4
740Lover
Newbie
 
Join Date: Nov 2021
Default

Quote:
Originally Posted by sbabbs View Post
I did it with E85 gasoline and 750cc injectors and 3 inch amm and straight pipe out the side and NPR intercooler and A cam and fuel and ignition chips. 5 speed manual trans 3.31 ratio rear third gear pull.





The thing about injectors and LH 2.4 is the injector size has to match the AMM size. 550cc works good with 3 inch AMM and gasoline. 750cc works good with 3 inch AMM and E85. Other then that you can adjust the injector constants in the fuel bin instead if you can or can buy a custom chip. So your 650cc injectors would be way to rich or to much fuel as they say. Something else to consider is if you run E85 you can overfuel it and you won't loose power like you would with gasoline.

Simon
Hmmm.. running E85? Doesnít sound like a bad idea at all. Roughly how expensive is it to do a job like this in a 740? Sounds worth the investment if I can run richer injectors with less power loss. I kinda love a rich setup
740Lover is offline   Reply With Quote
Old 11-13-2021, 03:24 PM   #5
740Lover
Newbie
 
Join Date: Nov 2021
Default

Quote:
Originally Posted by James M View Post
Redblocks don't have the headgasket issues you'll find with a lot of motors *cough cough, m20* you don't need headstuds or MLS gaskets for a 15g.

As far as learning what supporting mods to do give turbobricks a search, there is decades of info on here that can both directly answer the question and inform you of thing you never would have thought of.
Good to know ! So you believe the stock gasket and head bolts will handle 20psi alright? Also I most definitely will. Iíve been trying to here and there, thereís just so much that I feel like Iím in a storm of info ! Slowly getting more acquainted with how to navigate through the site though :D
740Lover is offline   Reply With Quote
Old 11-14-2021, 12:35 PM   #6
Lankku
Board Member
 
Lankku's Avatar
 
Join Date: May 2015
Location: Finland
Default

Quote:
Originally Posted by 740Lover View Post
Good to know ! So you believe the stock gasket and head bolts will handle 20psi alright? Also I most definitely will. I’ve been trying to here and there, there’s just so much that I feel like I’m in a storm of info ! Slowly getting more acquainted with how to navigate through the site though :D
It's not about the boost but cylinder pressure. Stock gasket and bolts can handle more than 400hp.
__________________
444 -55,
242 DL -80 (was 4.6l)sold, 245 -88 "B6284T" sold, 245 -92 "B6284T",
245 -90
Lankku is offline   Reply With Quote
Old 11-14-2021, 05:58 PM   #7
DurableSwedish
Hunting for a turbo
 
DurableSwedish's Avatar
 
Join Date: Dec 2003
Location: Hillsboro, OR
Default

That turbo is too small for 20 psi. It'll do it, but won't really make more power. You need to keep the intake air cold, add fuel or meth injection to over spin that little turbo.
__________________
One Volvo left.
1982 244ti (313chp), 2020 Nissan Leaf daily driver, 86 Yugo GV junk pile/gambler car
DurableSwedish is offline   Reply With Quote
Old 11-15-2021, 10:25 PM   #8
lookforjoe
Making Volvo Parts Fit
 
lookforjoe's Avatar
 
Join Date: May 2008
Location: Rockland County, NY
Default

Having played with the small Mitsu turbos in the past, there is little point in running over 1 bar boost - they just are not efficient for that use. Running even 7-8psi on the 15g should make for a good ride!

As sbabbs has illustrated, it can be done, but on a NA that was +T'd that you don't want to break?? Not a great idea.
__________________

My XR July2013 - 446AWHP @ 8K rpm C30 AWD conversion Feedback Thread
lookforjoe is offline   Reply With Quote
Old 11-23-2021, 02:04 PM   #9
jf.xv
Newbie
 
Join Date: May 2018
Location: UK
Default

You don't really need bigger injectors to run up to 15psi on a 15G. Even on a 16T (which isn't that much bigger than a 15G) stock injectors are fine to 0.9 bar (about 14psi).

If you go to bigger injectors then you're best off chipping the ecu to suit (and resistor mod required might be required too). Rather than dicking about with a 3" MAF or trying to hack it.
__________________
1997 940 RHD
215whp
Engine: B230FK - 16T at 12psi, 3" exhaust turbo back, V cam, wasted spark. Speeduino standalone ECU.
Suspension: GAZ adjustable dampers front, Bilstein B4 rear, -40mm lowering springs, polybushed in all the right places, lower chassis brace
Wheels: 17x9.5 ET0 rear, 17x8.5 ET-7 front
jf.xv is offline   Reply With Quote
Old 11-23-2021, 06:03 PM   #10
Dirty Rick
Board Member
 
Dirty Rick's Avatar
 
Join Date: Apr 2013
Location: Cornholio, OR
Default

650's on a 4 cyl are good for 380hp on gas with a .52 BSFC @ 80% d/c.

I agree that the turbo size is small for 20# boost, exhaust back pressure will likely tip it over.

I had to switch to a .60 AR turbine housing.
__________________
I don't know who I am when I am somebody else.
Dirty Rick is offline   Reply With Quote
Old 11-23-2021, 06:06 PM   #11
Fa182
Stage 1
 
Fa182's Avatar
 
Join Date: Apr 2016
Location: Austria
Default

Quote:
Originally Posted by jf.xv View Post
You don't really need bigger injectors to run up to 15psi on a 15G. Even on a 16T (which isn't that much bigger than a 15G) stock injectors are fine to 0.9 bar (about 14psi).
I too can confirm that stock injectors are plenty with a 16T at 12psi.
I'm running this very setup on my 940 + chips and a KL Racing Intercooler.
__________________
Fa182 is offline   Reply With Quote
Old 11-23-2021, 06:36 PM   #12
90volvo
Board Member
 
Join Date: May 2017
Location: Eldorado Springs Mo.
Default

My sons 240 we are running, 15g- TLAO chips- B cam- 3 inch ex. and aftermarket i.c. We went to the track. Runs 13.80s @ 102. We tried 16-20lbs of boost. Ran its best times at 16lbs never gained any mph with 18 or 20.
__________________
90 Volvo 240-my current setup.
B230ft rebuilt -MS-Turbo-E85

1985 240 Work in progress.

sons car- 93 240-15g turbo-chipped-95,000 miles. Slick car

Leave feedback- http://forums.turbobricks.com/showthread.php?t=355413
90volvo is offline   Reply With Quote
Old 11-28-2021, 08:28 AM   #13
martijn266
Board Member
 
Join Date: Apr 2020
Location: Zeeland, Netherlands
Default

I always ran my 16T with a kl racing intercooler, bigger injectors (470cc) and a chip. I plugged the hose coming from the turbo to the wastegate so it never opened. 3 inch exhaust also helps spool up that turbo, let it breathe! Pretty sure 21 psi was the max I could get out of that turbo. But the HG blew so guess I should've turned it down to 20 psi

I started at around 0.8 bar (11.6 psi) but I gradually increased, 15-16 psi was the most reliable though. If you run it at max boost the car also becomes very slow on a warm day compared to a colder day.
__________________
'97 940se. B230ft, upgraded intercooler, 16T turbo ran at 15psi, 3" exhaust, 470cc injectors and Bijlsma chiptune.
martijn266 is offline   Reply With Quote
Old 11-28-2021, 04:36 PM   #14
dl242gt
My car is fun hp club
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

Five star post! ^ That is the boost addicts progression. It's so much fun to do keep trying more boost. Then I old man copped out and keep it around 12psi or so.
__________________
Dave,
1982 242 turbo. 338k miles. MVP coilovers and 3" exhaust. Flowed 405 with a V15. Cossie turbine housing with upgraded compressor housing. 90+, IPD remote oil filter. Some other goodness, too. Been lots of fun over 25 years. Restored in 2k. Now ready for a 2nd restoration.

1993 245 Classic, 435k miles, enem V15. IPD bars and chassis braces. Simons sport exhaust from Scandix. sbabbs ezk chip. Been a good road warrior. Genuine Volvo rebuilt leaky M47.
dl242gt is offline   Reply With Quote
Old 11-28-2021, 10:59 PM   #15
VB242
Beep beep zip tang
 
VB242's Avatar
 
Join Date: Sep 2011
Location: The Right Coast
Default

Quote:
Originally Posted by dl242gt View Post
Five star post! ^ That is the boost addicts progression. It's so much fun to do keep trying more boost. Then I old man copped out and keep it around 12psi or so.
The view in the rearview mirror is much better at 25psi.
__________________
Deviant Volvo collector/cat herder.
VB242 is offline   Reply With Quote
Old 11-29-2021, 07:01 AM   #16
K9 240
Board Member
 
K9 240's Avatar
 
Join Date: Jun 2013
Location: Midlands UK
Default

I was curious as to whether I would benefit from water/meth injection at higher boost levels so I purchased four of those cheap Chinese Temp sensors. Put one just after the air filter, another after the turbo, one after the intercooler and one in the inlet manifold. Even if they aren't super accurate I can get a comparative idea of what's going on.
However, one question I haven't been able to answer is how hot is too hot? - at what inlet temp would water/meth be beneficial?
Tim
K9 240 is offline   Reply With Quote
Old 11-30-2021, 01:54 PM   #17
dl242gt
My car is fun hp club
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

I don't know what number to give you. But you don't want air temps after the intercooler to be too much higher than ambient.

The water/meth injection is mainly going to be used to bring down combustion chamber temps not air intake temps.
dl242gt is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 10:03 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.