50 trim too slow.... 1g big rods 2g pistons - how much more boost can i throw at this

[wjpowel]

my 50 trim is still too slow.... i have a 6 bolt w/ 37k and 1g big rods 2g pistons - how much more boost can i throw at this thing? i have heard of 17 psi on stock motor with 50 trim... but that sounds like your asking for a rod to break. please let me know what you guys think is safe with my current mods... which are available to view in my profile... thanks


I tune my car on Mitsubishi Motorway!! Who else on this site can say that??? who?

 

[fwdturbobov1996]

550's? On the evo3 I had my 550's maxed out at 23ish psi. I imagine at around 19-20 you would be getting pretty close.

 

[playitlouddsm]

I noticed in your profile you don't have any type of logger listed, with out some way of reading knock and fuel trims, i don't think it would be wise for you to start turning up the boost. If i were you i'd invest in a logger. But with a 50trim numerous people on here are running in the 20psi range.

 

[Boost Demon]

It looks like he has a wideban o2 to tune with, but I haven't tried tunning with one to know how good of a tune you can get out of it though .

 

[boostedinaz]

my 50 trim is still too slow.... i have a 6 bolt w/ 37k and 1g big rods 2g pistons - how much more boost can i throw at this thing? i have heard of 17 psi on stock motor with 50 trim... but that sounds like your asking for a rod to break. please let me know what you guys think is safe with my current mods... which are available to view in my profile... thanks


I tune my car on Mitsubishi Motorway!! Who else on this site can say that??? who?

The stock bottom end can handle a good amount of power, but it seems to me you are just flying by the seat of your pants with this. That will kill any motor real fast. First you need to get a logger and see if you are over running the injectors. Use that logger along with the wideband to see if you can get a better tune on the car with more boost, but I have a feeling those injectors are done. You really should be using something along the lines of 660's or 750's to support that 50 trim.

As far as what the block and internal parts will hold they will hold 20-25 psi without a problem, but the head gasket will come into play as well. It has more to do with your tune than the amount of boost you are running.

 

[alex]

550's? On the evo3 I had my 550's maxed out at 23ish psi. I imagine at around 19-20 you would be getting pretty close.

Yeah, with 550cc injectors, its an 18% increase compared to stock!

As far as max PSI, I would only push 21-23 PSI. I would get some type of management system whether is DSM Link or SAFC. Like "playitlouddsm" said, even a datalogger would help out!

-Alex

 

[alex]

Another thing too, I was reading in the Tech Guide and remembered seeing this:

Fuel Injector Upgrade
To supply the amount of fuel needed for a larger turbo, the stock fuel injectors will need to be replaced with higher flowing units. The larger the turbo you plan on upgrading to, the larger the injectors you'll likely need. If swapping in a 16G turbo, you can get away with 550cc injectors. Most T3/T4 combos will require at least 650cc and up.

I also have T3/T4 TO4E 50 trim setup. I have 1000cc injectors and I have to be careful about flooding my injectors cause they are pretty big.

-Alex

 

[boostedinaz]

I also have T3/T4 TO4E 50 trim setup. I have 1000cc injectors and I have to be careful about flooding my injectors cause they are pretty big.

-Alex

Why did you got that big and what are you using to control those?

 

[alex]

I have a DSM Link. It seems to handle fine, I had to do a lot of tuning to get it just right.

 

[boostedinaz]

I have a DSM Link. It seems to handle fine, I had to do a lot of tuning to get it just right.

Thats what I thought I just wanted to make sure.

 

[alex]

Only imagine if i didn't have any type of engine/fuel magement. Yikes!

 

[RotaryRyan]

I have a 50-trim running 23psi on the stock 6-bolt bottom end. I use 650cc injectors tuning with DSMLink. I have never seen my injector duty cycle go above 83%.

 

[Black94DSM]

650cc or 680cc injectors seem to be the best suited for the 50 trim turbos. You can easily run 20-25psi on your motor. Only thing is head bolts/head gasket, you can lift them fairly easily when you start pushing more boost on stock parts. Get some arps and a good hg.

 

[a_scobel]

Maybe it's cause you have an XS Power Tubular Manifold? kidding..

 

[wjpowel]

thanks for the input thus far... i actually have a afc that reads knock as well as an elmscan interface running obd-gauge on my palm m-100. Im only running 12 psi right now with a very conservative tune. this thing can handle 20 psi? im planning on trying 18 for pump gas for now... and see if the injectors can hold up without hitting 90%.

 

[AlumRodLaser]

The safc knock reading is not accurate.

 

[daren_p]

Yes anything that I have read say the knock feature on the safc for our cars is basically useless. This elmscan device that you have is it able to log timing? You want to log a WOT pull and look for areas where the timing is being pulled, this is where you are knocking. Once you turn the boost up you will max out those 550's fairly quickly. As for the 50 trim not feeling that fast, its more then likely your just not running enough boost as you won't be close to its effiency range at 12 psi. I'd start off with 18 and go from there, lots of guys are running low 20's daily on 50 trims.

Just took a look at your mods and see your running a 255 pump with no proper adjustable fpr (the B&M units is not a "real" adjustable fpr). With that pump you will be over running the stock fpr causeing tunning issues.

 

[wjpowel]

you are definately right about the B&M fuel pressure regulator, with no way to redirect extra fuel back, lowering the pressure is impossible. with the walbro 255 i am reading 48 psi fuel pressure (at idle) on the mechanical gauge on the fuel filter. I know this is an increase from stock levels, but I kept that in mind when i was making a base tune for the afc... thanks for the information however, about that knock reading being inaccurate on the afc. i have wondered because of discrepencies i have noticed, but with no way to log the afc (accurately) i cant go back and confirm that it was wrong.