25psi on 50 trim on 93 octane

[tsidrift1]

Just wondering, Im wanting to run 25psi soon. I was wondering when you guys are stepping up to race fuel on 50 trims? Is 25psi safe on pump gas(93 Octane), on a 50 trim?

Anthony

 

[JusMX141]

You can't base your results on other's experiences, unless they happen to be running the exact same setup that you are....down to fuel system mods and intercooler cores.

If you have a good, efficient intercooler core and plenty of fuel (which it appears that you do), anything's possible. I believe you should have no trouble running a consistent 25psi on 93 pump gas. There are guys running 25psi on pump gas with 16G's which are making WAY more hot air at that pressure than your 50 trim would be.

 

[jerseydiver84]

^^^^^^^^^^^^agreed 25psi on 93 shouldnt be an issue with your supporting mods, there are a lot of people who start running race fuel before they even reach where your at so unless you know someone with your exact build its all up to you and what you feel your car needs.

 

[turboglenn]

Even with the exact same setup there's still no good chance that some one else's results will be had with the same exact arts/boost as you. There's too may variables in the engine it's self before it's even modded to get 2 to run exactly alike.

You could run 25psi easily with retarded enough timing, but you start to trade off too much of your burn time for extra air input at a certain point. Look at Buschur, they've made 500+ horses at 30 some odd psi on pump gas with the Evo, but not only is there probably a few things none of us know, but i know for sure that they are running severely retarded timing on the few really high boost high HP Evo's they've got tuned on pump gas.

Adding methanol will gain you some timing and knock resistance back, or switching to E85 from the get go will allow you to go ahead and have it tuned to run 30psi daily. If you have to ask how to do this i can not suggest that you do the tuning as it's easy to waste a few grand or more when not knowing what you're doing.

Best of luck, take it easy on the boost until you do a LOT of searching and reading on here about boost and timing and the various "pump fuels" we have available with the introduction of E85 (IMO it's better than 12 dollar a gallon race gas) and that it's a whole lot cheaper is a fact.

 

[JusMX141]

I'm now a FIRM believer in the power of Meth injection. A good buddy of mine from a few states away just made almost 500whp on 93 octane pump gas running 34psi with a full T3 60-1 setup with absolutely ZERO knock. I never thought blasting Windshield Washer Fluid into your engine could be so beneficial!

 

[->PrOjEcTGS<-]

Start with some conservative timing at a MAX of 15*. Then, keeping an eye on knock, start upping your boost 1psi at a time till you reach your desired boost level. Or if you start seeing knock either take some more timing out or pick a lower desired boost pressure. Once you reach your boost pressure start increasing timing at 1* intervals across the board. Once you see knock then back the timing off 1* in the RPM that the knock occurred. All this while keeping your AFR in the high 10's low 11's. My car really likes 10.5-11.0. Really it's all just a freaking huge balancing act. I run my 16g @22-23psi with a MAX of 16* timing at redline on 91 octane (No Knock). With your more efficient turbo and 93octane I'm sure you can get away with 25psi. Maybe even more.

 

[tsidrift1]

I have thought about meth injection. I just basically want to make mid 400 to the wheels. I just got the wideband hooked up last weekend. I got my translator calibrated last night. I am wanting to start slowly raising the boost. I am still running 9:1 a/f from 4200 to 7k. Would it be safe to turn the boost up a little more and keep any on knock. If I see knock, I just advance some timing where it hits knock, right? Or, should I turn the fuel down some from 4200 to 7, before I turn the boost up?

Anthony

 

[JusMX141]

9:1 seems pig rich for pump fuel.

Even 10:1 is well on the safe side.

 

[tsidrift1]

Start with some conservative timing at a MAX of 15*. Then, keeping an eye on knock, start upping your boost 1psi at a time till you reach your desired boost level. Or if you start seeing knock either take some more timing out or pick a lower desired boost pressure. Once you reach your boost pressure start increasing timing at 1* intervals across the board. Once you see knock then back the timing off 1* in the RPM that the knock occurred. All this while keeping your AFR in the high 10's low 11's. My car really likes 10.5-11.0. Really it's all just a freaking huge balancing act. I run my 16g @22-23psi with a MAX of 16* timing at redline on 91 octane (No Knock). With your more efficient turbo and 93octane I'm sure you can get away with 25psi. Maybe even more.

Is there a way to set the timing to a max of 15 in Dsmlink. I thought you advanced timing a bit when you see knock? I could very well be wrong. Just tryin to get things straight before I turn up the boost. Dont wanna hurt the new motor. Its got 3700k on it now!

Anthony

 

[tsidrift1]

9:1 seems pig rich for pump fuel.

Even 10:1 is well on the safe side.

Thats what Ive thought. Ive turned it sown some already from 4200 to redline. It still hits 9:1 though. Thats what the wideband is reading though. Im running precision 880's with a 255 pump, fuel pressure set at 42? I believe, havn't looked at it in awhile.

Anthony

 

[tsidrift1]

I also read tonight, that its not good to run more than twice the amount of boos that your wastegate spring is setup for. I bought my tial with a 7psi spring in it. I am running at 18-19 psi right now. It seems that there is now problems. I did notice a few times that my boost gauge would get up to 18,19lbs and the needle would start bouncing real fast. Would this mean my spring is letting out as much as its going to? Do I have to buy a new spring?

Thanks for all the help so far guys,

Anthony

 

[->PrOjEcTGS<-]

I also read tonight, that its not good to run more than twice the amount of boos that your wastegate spring is setup for. I bought my tial with a 7psi spring in it. I am running at 18-19 psi right now. It seems that there is now problems. I did notice a few times that my boost gauge would get up to 18,19lbs and the needle would start bouncing real fast. Would this mean my spring is letting out as much as its going to? Do I have to buy a new spring?

Thanks for all the help so far guys,

Anthony

Yes, double the spring pressure is generally what you will get. There are ways to make it hold more. I would get a spring that is 1/2 the pressure that you will run as a max. If you think you will never run more than 30psi get a 15psi spring. 28psi = 14psi spring. And so forth.

And NO do not advance timing if you are seeing knock. I'm not familiar with DSMlink but I'm sure you have control over your timing with it for specific RPM points on the WOT map. Not sure if it's as much as I do with Tunerpro but you paid good money for it, it should have great features. Right...

 

[1992awdlaser]

First let me say I didn't read all of it. So you might read something that you have already read.


1. Advancing timing can cause knock and makes more power. If you are already knocking, advancing timing will have a 99% chance of making the knock worse.

2. Retarding timing is the opposite of advancing timing. However, timing being too retarded on a high octane fuel can cause knock.

3. You want to be in the high 10's low 11's a/f wise. Use the fuel sliders in link for this.