Max safe boost? [Merged 10-6]

[Turbolaser]

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

 

[xxraptor660xx]

I was running 10psi, and at WOT the car would boost then backfire like crazy. I raised it to 1.5kg/cm3 (21psi) and the car runs amazingly quick. Is this unsafe? Will it cause heat soak?

 

[Black_Bullet]

WHOA with what mods?

If i dont hear front mount, bigger fuel pump, bigger injectors and/or increased fuel pressure, and some sort of tuning device then im going to tell you to turn the boost back down to 10 asap unless you want to come here next week and make a thread about how you blew your engine by not having supporting mods....

Edit: Never mind I just checked your profile for mods... Shouldve done that first before commenting.

Say you have
Aeromotive FPR with gauge, Walbro 255 fuel pump, RC 550cc fuel injectors, Blaha modified MAF , Dejon tool intake piping, custom turbo outlet pipe, EVO III Big 16g, 2g ported exhaust manifold, Tial 38mm external wastegate with dump, ported 02 housing, 2.5" exhaust/Apexi N1 muffler, upgraded intercooler pipes, Greddy type S BOV, Autometer boost gauge, Autometer A/F gauge (narrowband), REAL HID headlights.

Only thing I ask is do you have a logger ? Have to check for knock reguardless of what your mods are...
And hope your not tuning off that a/f ratio guage, you need a wideband...
Due to you having a 1g and running a safc w/ larger injectors your increasing your timing adv in order to
compensate for the inj . 1gs already run aggressive-ish timing out the box; 21psi with 20+ deg of timing might not
work well with pump... I barely get away with 11.1 afr, 1g timing maps at 19 deg timing on stock compression ratio with 20psi for example in which 19deg is lower than stock top timing adv and I dont have a safc bumping my timing up... Catch my drift....

p.s. oh if you have boost leaks it will make your air charge even hotter due to the turbo working harder, and I dont think I saw a fmic in your mods list so yea it will def be heat soaking after about 5-6 seconds under 21 lbs of boost.

 

[xxraptor660xx]

Haha I wouldn't rely on my a/f gauge for shit. It's kind of just a cool looking light show. I have a datalogger, but it doesn't connect when I plug it in. I'm currently tuning with S-AFC, and controlling boost with AVC-R. I can't really log knock because my datalogger wont work. Thanks for your input!

 

[Black_Bullet]

Even if you dont knock in 1st and 2nd gear, your bound to knock in 3rd on up during higher load of the engine... I wouldnt go wot at 21psi in say 4th gear for example without a fmic. And if your not running meth or a bigger fmic i wouldnt even run 21psi on a sidemount unless it was a supra side mount and even then youd be really pushing it ...
Your set up looks good for 15-17psi max depending how long you planned to whomp it and depending the condition of everything else. Turn the boost down...
Good luck...

 

[fastaseagle]

You can run 20psi but its really up to you.. I have always ran like 18-19 with that same seetup you wont run out of injector until about 21 or so the the 255 will take you a long way.. I made 550 with a single walbro 255 not even rewired. The 1g fwd I have now runs 15-16 on stock pump and stock injectors.

 

[zippyshoe]

Without a datalogger to monitor injector duty cycle and knock, I would play it safe and keep your boost at 14psi or less until you upgrade your stock injectors and/or invest in a logger. The Big16g will flow more air (lb/min) than your stock turbo at the same boost pressure and will therefore require more fuel than the stock turbo at the same boost pressure. One of the worst things you can do to an engine is to allow it to run lean, especially while under boost.

 

[dsmeclipse16psi]

how much boost can t25 push???

 

[hopwoodp]

You don't want to go above 16 psi, otherwise you will be blowing hot air.

 

[dsmeclipse16psi]

so 16psi is the max it will push without messing anythng up

 

[gsxeclipse97]

There is no point to go over 16 because the turbo is basicly maxed out when you get the car from factory

 

[hopwoodp]

16 psi is right about at the limit of the t25 turbo. But, you need to make sure there are no boost leaks and everything is operating correctly or you will run into a problem.

 

[dsmeclipse16psi]

i just got the car recently and the guy who ha it had a new motor put in along with mods i dont know if he upgraded the turbo i know was running 22psi on it today until i blew off one of the intercooler cuplings

 

[dsmeclipse16psi]

so is it possible for a t25 to make 22psi??

 

[hopwoodp]

You need to double check what turbo you have. If it looks like a t25 then there is only two possibilities: It is a t25 or t28. The t28 turbo was not made to boost above 21 psi, so either way they could have messed something up.

Now, as for your hoses or couplings leaking or blowing off, means that they were not secured well enough for that boost level or didn't have the ends of the pipes beaded, which will cause that to happen.

Post a picture up of your turbo.

 

[dsmeclipse16psi]

well seethis is my first dsm so i couldnt really tell what a t25 looks like that is the problem like i said he did lots of mods so i dont know if its a differnt turbo but i cant paost a pic until next week but i can see like numbers on the turbo maybe i can tell by them??

 

[dsmeclipse16psi]

i dont know the exact numbers but they are like td05h r smthing can you tell by these numbers??

 

[hopwoodp]

Here is a link that will show you what they look like:


http://www.gpopshop.com/mitsdsmturbos.html

 

[RedTurboEclipse]

Take a picture, you prob don't even have a t25 seeing as you are saying it says TD05H on the compressor housing?

 

[dsmeclipse16psi]

so can you tell by the numbers on the compressor housing??

 

[hopwoodp]

td05h usually refers to a 14b, 16g, or 18g turbo.


Here is some info from RRE that explains how to identify some of the mitsubishi turbos. Don't pay attention to the injector part.

TDO4 (written on the compressor housing) Tiny turbo from an Auto Tranny car. Same motor, tiny turbo and manifold.

TDO5-14B: All the vanes on the compressor wheel will be the same size. Injectors will be blue (450cc).

TDO5-16G: The vanes on the turbo will be alternating big/small/big/small. Injector color is still blue (450cc)

Big 16G: The vanes on the turbo will be alternating big/small/big/small. Injector color is yellow (510cc)

 

[dsmeclipse16psi]

ok i just looked it has TDO54 written on the compresor housing

 

[hopwoodp]

Pull off the intake pipe and take a picture of it. Also, see if you could get a picture of the actual part number.

 

[dsmeclipse16psi]

ok i'll do that tomorrow thanks for the help so far by the way

 

[dsmeclipse16psi]

but like i said it has td054 on the compressor housing can you not tell by this number??

 

[romeen]

so is it possible for a t25 to make 22psi??

This may be a moot point since it sounds like you don't have a Garrett turbo but a T25 can momentarily hit 22 psi and more but it cannot maintain it and it certainly won't be efficient whatsoever at that boost level. When I first started modding my car I had an issue with boost spike. Both of my digital boost guages (dual turbo timer and EBC) both showed via the peak hold display that my T25 was repeatedly hitting 24 psi and then immediately falling off.