[IlChengis]

Originally Posted by Hit_Apex

Not sure you made a point with this reference. What was the downside of their impatience? Were the stock turbos failing at an alarming rate?

The 2nd Gen DSM platform ('95-'99) was equipped with the Garret T25, a smaller turbo than the Mitsu 14B in the 1st Gen ('90-'94). The 14B (as well as the 1G BOV) was a very common upgrade for 2G owners that didn't have the budget/desire to buy a bigger turbo and supporting mods. Some of the 2G DSM guys would push their T25 several psi past their "enthusiast recommended" thresold. Most of that extra pressure was just hot air and wouldn't even yield additional power.

That was just an example of another FI scenario (with another platform) where an upgraded turbo was the only way to reliably make power because the stock turbo was being run to its limits.

Does it make sense now? I should have been more specific.

-Walter

[E90Vader]

Can you run the RB turbos at 18 - 19 PSI without running meth??? Provided you don't track it and watch engine temps?

[Trevor008]

Originally Posted by E90Vader

Can you run the RB turbos at 18 - 19 PSI without running meth??? Provided you don't track it and watch engine temps?

If you want to run lean then sure

You'll need meth(lots of it!) and race gas at this point if you want to run 19psi. 18psi you'll probably still need both but might be able to get away with meth and 93 or race gas and no meth. You'd have to log and moniter to be sure though

[E90Vader]

So your saying 17 - 18 max without meth?
I didn't realize meth was so important. I'll have to do some major research to understand exactly what meth does.

Also for a daily driver, how long a tank of meth lasts ETC.

[Trevor008]

I'm saying that every car is different and that you need to log frequently to see how your car is handling things. 17-18psi seems to be safe if you are running 100+ octane but you need to make sure it will work on your car.

As for meth, it not only cools the intake charge allowing you to make more power, more importantly in this situation, it adds octane. As for how long a tank lasts, that depends on how you have it set up and how you drive.

[Brey335i]

I have seen RB turbos put down 450 whp at 15 psi pump gas... I would not run them at 18-19 without fueling or meth

[scottp999]

Originally Posted by Brey335i

I have seen RB turbos put down 450 whp at 15 psi pump gas... I would not run them at 18-19 without fueling or meth

True that. 15PSI on stock turbos is not = 15 PSI on upgraded turbos.

[D335NUTZ]

I wouldn't mind running RBs with 93 and FBO and no meth at a 15 psi

[dzenno]

You shouldn't run more than 15psi on pump gas with RB turbos...this is with even 94 pump gas up here in Canada...if you log your fuel trims you'll see the stock system is maxing them out at just 15psi on RBs maybe even a touch before that...

15psi on RBs vs 15psi on stock turbos is about a 50-70whp difference, no meth...on top of that given that the RB turbine wheels are larger than stock your EGTs won't go as high as on stockers, which induces knock...

[Malaka1]

Originally Posted by dzenno

You shouldn't run more than 15psi on pump gas with RB turbos...this is with even 94 pump gas up here in Canada...if you log your fuel trims you'll see the stock system is maxing them out at just 15psi on RBs maybe even a touch before that...

15psi on RBs vs 15psi on stock turbos is about a 50-70whp difference, no meth...on top of that given that the RB turbine wheels are larger than stock your EGTs won't go as high as on stockers, which induces knock...

I have been running 15.5-16psi on 93 octane w/ my RB's pulls strong and ignition timing looks good.

[vadim83]

do you guys know that bmw has thicker headgasket for our engines? it will lower cr slightly, not sure if it helps to run 18psi without meth but still we have that option and I'm wondering why nobody tried to go this way..at least we are able to order that thick headgasket in European bmw parts catalog..and I must say I don't really get why people get meth system, it's toxic, not really reliable and car that needs something beside fuel feels kinda weird for me :-)

[dzenno]

Originally Posted by Malaka1

I have been running 15.5-16psi on 93 octane w/ my RB's pulls strong and ignition timing looks good.

You "can" run it ... i've run the same as well for testing a few times...what saves you is direct injection's ability to run leaner than typical as it cools the in cylinder temps WAY better than port injection, and that's why DI is so f* cool...the problem with just running Xpsi, or in other words raising it to whatever we feel like, is the ECU can adjust fuel trims up to +/-34%...basically take away/add that much fuel in closed loop operation through stock programming...it will not do more than that...once it does that you're basically into unchartered territory...i'd advise strongly in logging your short term fuel trims and make sure that whatever boost you choose to run you're always within this +/- 34% range or you're pushing it...your timing curve might look just fine one run, but on the next, due to scorchingly high EGTs, you're running your chance of melting a piston, all that while having a PERFECT timing curve!

Engine safety is NOT only exclusively dependent on those timing graphs and many ppl forget that...

[dzenno]

Originally Posted by vadim83

do you guys know that bmw has thicker headgasket for our engines? it will lower cr slightly, not sure if it helps to run 18psi without meth but still we have that option and I'm wondering why nobody tried to go this way..at least we are able to order that thick headgasket in European bmw parts catalog..and I must say I don't really get why people get meth system, it's toxic, not really reliable and car that needs something beside fuel feels kinda weird for me :-)

We run it as there's no other alternative to additional fueling to running higher boost "safely" (with proper safeties in place)...

[Malaka1]

Originally Posted by dzenno

You "can" run it ... i've run the same as well for testing a few times...what saves you is direct injection's ability to run leaner than typical as it cools the in cylinder temps WAY better than port injection, and that's why DI is so f* cool...the problem with just running Xpsi, or in other words raising it to whatever we feel like, is the ECU can adjust fuel trims up to +/-34%...basically take away/add that much fuel in closed loop operation through stock programming...it will not do more than that...once it does that you're basically into unchartered territory...i'd advise strongly in logging your short term fuel trims and make sure that whatever boost you choose to run you're always within this +/- 34% range or you're pushing it...your timing curve might look just fine one run, but on the next, due to scorchingly high EGTs, you're running your chance of melting a piston, all that while having a PERFECT timing curve!

Engine safety is NOT only exclusively dependent on those timing graphs and many ppl forget that...

Quite true, I will do some more logging and I guess in the meantime back it down to 15 psi or keep my meth tank full.

[dzenno]

Originally Posted by Malaka1

Quite true, I will do some more logging and I guess in the meantime back it down to 15 psi or keep my meth tank full.

They're absolute monsters even at 15psi pump gas how do you like yours?

[Malaka1]

Originally Posted by dzenno

They're absolute monsters even at 15psi pump gas how do you like yours?

What I like about them is that at 15psi in 90 F weather the car pulls harder than earlier this winter with stock turbos +meth in 30 F temps. The most boost I have ran so far with the RB's is 16.5psi w/ a 60/40 meth mix and it moves!! Gotta get my new tires installed though, all I do is spin in 1st and 2nd gear. After that I will be throwing in some race gas + meth and heading to the dyno and 1/4 mile to see what results I get.

[TheAcAvenger]

7th on the wait list... i ordered march 1st LOL.

this batch needs to come out asap

[Syndicategt]

Originally Posted by TheAcAvenger

7th on the wait list... i ordered march 1st LOL.

this batch needs to come out asap

Same shoes, except I was somehow bumped from #10 to #12 now

[anonemouse]

I also run the RBs at 15PSI on 93 Octane. Not willing to go above this until I get the new meth system or fuel pump upgrade.

We know RBs have the potential to do more but even at this power level biggest problem is getting the power to the ground.

A.

[Elie335]

Originally Posted by Syndicategt

Same shoes, except I was somehow bumped from #10 to #12 now

WOW, how much time is that equal? 6 months maybe ? lol

[TheAcAvenger]

ouchhh syndicate. that hurts.

[Syndicategt]

Originally Posted by TheAcAvenger

ouchhh syndicate. that hurts.

Only hurts because I beleive the next batch going out are 10 units.