Max safe boost? [Merged 10-6]

[Turbolaser]

Is it safe to do the boost contol solenoid mod on a stock 1G?

 

[Bud92gsx]

Guys lots of bad info here. The 1G 450cc are ok for 15ish psi with stock pump granted there are no boost leaks the rest of the system is up to snuff. He is running the small 390cc injectors so with out a logger I would only push 11-12 psi.. Also to run the 450cc injectors and not go hog ass rich you will want to get your hands on the 5 speed ecu that is setup for the 450cc blue tops!

1g auto fpr is 43.5 psi flowing 390 ccs on the auto..The 5 speed 1g cars actually flow about 410 ccs of fuel thru the 38 psi of fuel pressure..

I had an ebay e3 on 390s witht he boost creeping..Never hit cut on the stock ecu..Not saying to do this by any means..But it has happened..

yeah it's 13g not 13b.. i had also thought that until i learned that Mitsy 3000gt vr-4s have the 13gs stock and guys upgrade them to the 14bs

GTo's actually have 9b's not 13g's..The 13g compressor whel is an upgrade to the 9b, but the cpmp cover needs to be redone to fit the wheels..

 

[918johnson]

OK I ran the numbers on my turbo its the small 16g but I guess I'll just go to 12psi? And tune as much as I can withe the wide band

 

[Bud92gsx]

OK I ran the numbers on my turbo its the small 16g but I guess I'll just go to 12psi? And tune as much as I can withe the wide band

If your profile is correct thats all you can do..And rewire the fuel pump.

 

[918johnson]

What do you mean by rewire the fuel pump ?

 

[Bud92gsx]

>Rewire Fuel Pump

 

[918johnson]

OK what does rewireing do ? Just run the max psi?

 

[91stocker]

OK what does rewireing do ? Just run the max psi?

You gain 30% more in potential fuel flow. For $30, the gain per dollar cant be beat.

 

[918johnson]

OK thanks guys for all the info guess I'll start rewireing this week

 

[JD336]

im building a 1990 eagle talon tsi with 1g rods and 2g NPR pistons .20 over
apr head studs
apr rod bolts
acl rod and crank tri bearings
stock head
fmic
smim
2g port and polished exhaust manifold
Mhi small 16g with 7cm polished exhaust housing
external wastgate
mbc
greddy bov
clutchmaster light weight flywheel/3 puck cluch/2500lb pressue plate
Full 3" exhaust
Autometer: boost, oil pressure, O2 guage

and next year the plan is to go with 660s, afpr, and a walbro 255 wired and dsmlink


shooting for a 300 - 350+ daily driver


I'm curious as to when it's broke in what boost I should be safe at?

 

[91stocker]

I'm curious as to when it's broke in what boost I should be safe at?

That will be determined as you tune it. Simply up the boost, while watching the logs. Things like your afr's, knock, and idc's will tell you how much boost you can get away with.

 

[JD336]

Alright.

Also what do you suggest on breakin procedure?

 

[gofer]

im building a 1990 eagle talon tsi with 1g rods and 2g NPR pistons .20 over
apr head studs
apr rod bolts
acl rod and crank tri bearings
stock head
fmic
smim
2g port and polished exhaust manifold
Mhi small 16g with 7cm polished exhaust housing
external wastgate
mbc
greddy bov
clutchmaster light weight flywheel/3 puck cluch/2500lb pressue plate
Full 3" exhaust
Autometer: boost, oil pressure, O2 guage

and next year the plan is to go with 660s, afpr, and a walbro 255 wired and dsmlink


shooting for a 300 - 350+ daily driver


I'm curious as to when it's broke in what boost I should be safe at?

You're going to be knock limited to the amount of boost/timing advance you'll be able to get away with, which is usually the case on any pump gas setup.

Since you aren't doing ANY fuel system upgrades until next year the max safe boost you can run is off the wastegate actuator, 12psi. So there's no need for you to go to an external wastegate setup or install a MBC to increase boost until you upgrade injectors and the fuel pump.

I highly recommend going back to the drawing board on your mods list, it's a bit backwards.

This is the "Max Safe Boost" thread not the "Engine Break In" thread, go do some research on break in procedures and ask your questions in the appropriate thread please.

 

[JD336]

Sorry I'm new to the dsm world!
All I was looking for was advice, I've done alot of research up to this point. This is my first dsm build and I'm trying to do things the right way. I didn't know asking simple questions to people who have done this before was a bad thing.

 

[91stocker]

Yea really all you'd have to do is trade out, the smim and external wg set up, on your list for dsmlink. You'd be all set then. No need for a smim or a external wg on a 16g anyhow.

 

[GSXV8Killa]

I was wondering what I could do safely to turn the boost up over stock without a tuning system. Maybe a little bigger injectors? I understand it would run a little rough at idle/low rpm. I will list whats on the car and just looking for feedback on what I could turn and where to safely turn it up too. Please dont tell me to go buy a tuning system. Just looking for an answer to the question I asked. Thank you.

Part list:

Stock rebuilt long block with 20k
MHI Big 16g turbo
FP manifold
Hallman PRO mbc
ARP head studs
Cometic MLS head gasket
Magnacore 10mm wires
BPR7ES
FMIC
Aeromotive FPR
Walbro 255
3" Apexi downpipe
3" Apexi N1 turboback exhaust
Oil PSI gauge
AEM wideband
Boost gauge
Aluminum radiator with dual slim fans

 

[snowborder714]

...safely to turn the boost up...without a tuning system...Please dont tell me to go buy a tuning system

Does not compute.


Yes, you will want bigger injectors with a 16g. Then (I guess...) you can try to monitor everything that's happening with the car all through the wideband gauge

Oh, but wait...you'll need a tuning system to control those bigger injectors. Forget that suggestion.

 

[GSXV8Killa]

I just wanted to know if I could safely just turn the boost up a few pounds without hurting anything and I kinda figured I would get fuel cut running the stock injectors by doing that. Im new and was just looking for some feedback on this and if it was possible. I understand I need a tuning system but I didnt know if I could manage without one just going up to 550's or something.

 

[JusMX141]

I just wanted to know if I could safely just turn the boost up a few pounds without hurting anything

We can't answer this for you. It all depends on factors like exhaust backpressure, ambient air temp, intercooler efficiency and pressure drop...things that I'm sure you have no clue about let alone some guys on a forum.

If you have to ask, then it's probably not a good idea to do so.

 

[snowborder714]

Nope, any injector increase on a 2g will need a tuning system.

You might be able to run 12-13 lbs of boost on stock injectors, but I think anything above that will push the stock injectors too far.

 

[gofer]

I was wondering what I could do safely to turn the boost up over stock without a tuning system. Maybe a little bigger injectors? I understand it would run a little rough at idle/low rpm. I will list whats on the car and just looking for feedback on what I could turn and where to safely turn it up too. Please dont tell me to go buy a tuning system. Just looking for an answer to the question I asked. Thank you.

Part list:

Stock rebuilt long block with 20k
MHI Big 16g turbo
FP manifold
Hallman PRO mbc
ARP head studs
Cometic MLS head gasket
Magnacore 10mm wires
BPR7ES
FMIC
Aeromotive FPR
Walbro 255
3" Apexi downpipe
3" Apexi N1 turboback exhaust
Oil PSI gauge
AEM wideband
Boost gauge
Aluminum radiator with dual slim fans

Is this a parts wishlist or a list of modifications that have already been installed on the car?

If these parts are already on the car then you have the tools necessary to turn up the boost and MONITOR your cars AFR's while doing it. The only reason why we suggest not turning up the boost with the stock injectors is the chance you'll lean out and detonate, however, most people don't have a wideband installed either so they've got no way of monitoring their air/fuel ratio.

Turn it up and monitor your AFR's and if they're going leaner than 11:1 then you're stretching your injectors and you need to turn it back down.

If that's just a wishlist of parts that aren't actually installed on the car then don't turn up the boost at all.

 

[snowborder714]

The only thing I was concerned about Corey is that 100%+ IDC's won't necessarily produce an 11:1 AFR, will it?

 

[gofer]

The only thing I was concerned about Corey is that 100%+ IDC's won't necessarily produce an 11:1 AFR, will it?

You are correct. Theoretically, if he's seeing 11:1 AFR's running 18psi at 5k RPM then as airflow increases going further into the powerband his AFR's would continue to lean out. That's why I mentioned if it ever goes leaner than 11:1 during the pull then it's time to back off the boost controller a bit...

If he's running wga boost on a 16g then 12psi and the stock fuel tables there's no way he's close to 11:1's, probably a 9.2~9.5:1 AFR if I had to guess. He's also got a AFPR and a Wally 255 so honestly he could run up base fuel pressure to 50psi and stretch the 450's to a 480cc injector if he wanted to get even more out of them.

My only issue with all of this is the fact that all that money was put into mods and not a dime was spent on tuning software, it makes no sense. But, if you must, there should be no problem increasing boost levels until 11:1 AFR's are met and then leave it there until you can get a means to log/tune everything. Just constantly monitor your AFR's when you go WOT and make sure it's staying 11:1 or even a bit richer...

There's a disclaimer doing all this but it seems he already knows what it is since he said, "please don't tell me to go buy a tuning system." The good news is that 2g timing tables are really conservative so cylinder pressures shouldn't be high if the car does go lean for a second, lean being 11.3~11.5:1.

 

[GSXV8Killa]

Is this a parts wishlist or a list of modifications that have already been installed on the car?

If these parts are already on the car then you have the tools necessary to turn up the boost and MONITOR your cars AFR's while doing it. The only reason why we suggest not turning up the boost with the stock injectors is the chance you'll lean out and detonate, however, most people don't have a wideband installed either so they've got no way of monitoring their air/fuel ratio.

Turn it up and monitor your AFR's and if they're going leaner than 11:1 then you're stretching your injectors and you need to turn it back down.

If that's just a wishlist of parts that aren't actually installed on the car then don't turn up the boost at all.

This is not a wishlist. The list I provided is what is currently installed on the car. I have many more parts not installed yet but those will come in time when more funds are available. I purchased an aem ems series 1 for my long term goal a few months ago. I dont have a laptop nor do I know how to use the software. I dont want to start making adjustments or altering things when I am not educated on it. I live 30 mins from STM and that is who will be tuning the car once my part list has all been purchased. Im not going to pay to have the car tuned now and then pay again down the road once I have everything I need for my build. I posted this thread for the sole reason of seeing if I could turn the boost up some with my current mods. Im not looking to make huge gains here I understand that completely. ONLY wanted to know what I could do with what I have and what that limit would be. Thank you GOFER for the information you have provided so far. I appreciate it.

 

[gsxeclipse97]

Tonight I got fuel cut on the 14B at 15 psi. So all cars are very different.

 

[Diamond Star Werks]

Tonight I got fuel cut on the 14B at 15 psi. So all cars are very different.

Max safe boost is 14# on a 14b for any dsm wroth 450cc injectors. With a stock exhaust cut after the resonator I could run 17-18. With apexi 3" I couldn't run 15#. Is all according to how good your car breaths. Boost is back pressure.