well i dont know i need to get my map sensor to work so i can log the psi and all. but it seems to spick to 25 not really holding it to well. but drops off and by red line as i said at 18-19 bad days is like 16-18.

 

22 is not okay at all. unless you have bigger injectors and the thing is tuned to handle it. for stockj set up if ur looking for a little more power buy a MBC and turn it to around 20 or 21 tops. at 22 the ecu will start pulling timing and you will LOSE power instead of gain it. plus dont run higher boost without getting headstuds. peace out

 

You dont need bigger injectors at 22psi. The only thing you need to run that boost is a good flash. I was running 1.5bar on the stock FMIC/engine/turbo/and fuel system with just a mbc, boost gauge, tbe, and base flash by dynoflash and on pump gas which is 91oct here.

 

Warr how can you say that running that much boost on pump gas is stupid? Think about your statements please before you post, as people regard your advice as wisdom on this forum. In regards to the post, its primarily in the tuning combined with other contributing factors, there is no right or wrong number. A IX recently hit roughly 310whp on a DD on 91 OCT peaking at 25psi! That equates to about 360whp on a dynojet. This was only with a custom tune and catted 3" tbe, so anythings possible. Of course IXs are less prone to knock compared to an VIII but the logic is the same. Theres not a set number for whats safe and whats not. It all depends on the car and the tuning. Check the link!

https://www.evolutionm.net/forums/sh...d.php?t=206174

 

Warrtalon is trying to save you and everyone elses engine by not advocating the ok for pump gas @ 25psi. I personally would never run pump at that rate. I may do it at 22psi but not often.

 

I run 23psi on my stock turbo all day long. Now I dont know if that's a good idea on stock injectors, because I have 720cc injectors. My duty cycle at that boots amount is in the 50-60% around 6500rpm. I think 23-24psi is attainable on the stock turbo with supporting mods (turbo back exahust) with the right tune. It's all about the tuning.

 

SKIL thats because you're super conservative which I can respect. But the FACT is that you can run that much pressure SAFELY if the car allows it on a day to day basis, but of course every car is different and not all can do so. And its only possible in the hands of a skilled tuner who really knows his shyt. As far as running 24-25psi on pump I believe only the IXs can achieve this safely.

 

My Evo IX has been running fine for the last 6 months on premium quality pump gas and maximum 25 psi boost.

I am still running the stock ECU without any adjustment and the car is fitted with a 3" exhaust. There is no sign of any detonation or knock at all and the plug colour is fine. It seems that the new ECUs do not have a fuel cut and can adjust to suit the extra boost quite well.

I achieved the increased boost by placing a small restrictor in the pipe that leads from the tubo outlet to the T piece which makes the connection to the waste gate pipe and the two electronic boost controllers.

 

whats your whp

 

Yeah but look at what you said. It has to be tuned for it. Which is the key here. I would never advocate pump on 25psi even if you do get tuned but it would be better if you were tuned. However, dynoflash can setup a tune for you to run pump @25psi but IMHO it will be a ticking time bomb. It will of course run fine for now but what about 50000miles from now?

Can it be done? of course. would it be smart? nope. Will you have problems? only time will tell

But at least with my advice you know your car will last alot longer than someone running pump at 25psi.

 

We dont have any solid evidence that shows running that much boost will kill your car in the long run even with a good tune. It varies with each car so each scenario is different. The bottomline is that if there are no signs of detonation and the a/f is clean and happy, that much pressure will not effect the longevity of the car. Again, its only possible to safely and reliably run this much boost on a IX with proper tuning/mods, the VIII's just cant do it safely

Also note the 25psi peak is only for a few hundred RPM's and tapers in the upper part of the powerband normally as it should. I'm not advocating holding 25psi till redline THAT is dangerous and the turbo is functioning well beyond its efficeiency range as well.

 

29psi thats what im running.

 

I understand this however, running at 25psi with pump gas has a increased pronality of knock and detonation(which will occur) than running on race fuel. And if this is the case which we all know it is then the longevity of that car will be decreased inregards to the one who is running race fuel. Thats all I am saying. And because of this I wouldn't recommend that as a way of use. I know many people who actually run their cars on pump at 25psi. Have they had any problems? No, but thats not to say they wont. Hell, they haven't even exceeded 30000miles yet so like I said only time will tell. Lets wait about 5yrs and see who is having to do engine tear downs because they spun a rod bearing or etc etc.

I try and give advice with the sake of longevity in mind. If you dont mind doing engine rebuilds then by all means boost that sucker up on pump and let me know how it goes.

 

I have been HOLDING 23psi to 6800 rpm in 1st-3rd gear and 24psi in 4th and 5th all the way to 7500 for a LONG time now on pump gas. I have turned it up to 26psi on accident once for only one pull in 2nd gear, but I am going to give that a try on race gas tonight and see how she does. I'm trying to pull my friends BR Stage 4+ that traps 112 and made 330whp on his Mustang.

This is my stock car with a MBC that I made myself and no tune. I daily drive it 60 miles a day to work and back, beat the hell out of it the entire way, do several pulls a week to 150mph holding 24psi and I have had no problems and show no signs of detonation.

Warrtalon if just turning up the boost alone doesn't add power, then what is the reason that my stock car picked up 7 mph through the traps by only turning the boost up?

I love this site.

 

hey drag how do you have your setup with a MBC and all do you also have the stock boost solnoed in or no.