More boost with less timing still results in more power. I run 25 psi on 93 daily. If I turn it down to 22 or so and add the whopping 1 degree extra it'll take, it's slower. I tried it on this car, even though I know better from my DSM days, but hey, it's a different car. Same theory applies. More airflow makes more power, even with a degree or two less timing. There are better ways to increase airflow than boost (more pressure is more heat), but with excellent intercooling you can get away with more boost on pump gas. YMMV.

 

This also raises your EGT's, do you have an EGT probe?

 

I ran an EGT gauge on the 2g for a couple years, until I realized how worthless it was. AFR and actual timing had little effect on it. Large timing drops due to knock showed up quite readily, but with DSMlink or other tuning devices showing you what knock actually is, there wasn't much use in it. At any rate, dropping timing a couple degrees to run more boost is not going to have a significant on EGTs, and if it does, there is a known good reason for it.

 

along these lines ^^^, I have always wondered if you would benefit from running higher boost on pump gas (with less timing) when stepping up to a bigger turbo...


A lot of the bigger turbos (let's say a GT35r) need significant boost to shine. The amount of boost needed cannot be safely run when on pump gas. But what if the tuner were to compromise by upping the boost and running less timing?


My question is, when people tune their GT35r on pump 93, wouldn't they make more power by running less timing to try to hit like 24-25psi on pump (assuming tuned for no knock...) ?

 

Possibly. But I wouldn't buy a GT35r and then worry about making power on ****ty 93

 

race gas where i live is like $165 for 5 gallons, cant afford to run race gas so my only option is pump for the time being

 

Wow....5 gallons of 111oct for me is $34.25 exactlly...

Where the heck do you live?!

 

Scotland - Edinburgh, i wonder if i had like 50 gallons shipped to me if it would be possible without too much extra cost

 

more to the point alan678 where do you find 111 oct for 34 bucks? i need a hook up like that!

 

I personally never run less than 25 psi on anything, assuming the turbo is big enough to do it. I run 25 psi daily on my EVO Green/20gLT. I also ran 25 psi daily on a 6h-20G, 6h-50 trim, 35R, T67, etc. With a typical good setup, there is no problem doing it on 93, in my experience.

 

but on the bigger turbos you mentioned ^^^ , were you seeing any noticeable gains at 25psi with less timing on pump 93, over others running the same turbo on pump at like 22-23psi but with more timing?

I know people have said that, on the stock 16g, there is not much to gain by running higher boost with less timing over the traditional, more conservative tune... but on some of the bigger turbos out there (that need a little more boost to shine - i.e. 20gLT, GT3076r, FP3065, 35r, etc...), wouldn't this actually be a worthy trade-off?

this is all assuming one was running pump gas...

 

I would never waste time compare to someone else's car, I simply ran several boost levels, tuned for each, and noted the performance changes at the track. For the last 7 years I've been going to the dragstrip weekly, and I've collected ****loads of data on all kinds of setups. More boost with a little less timing always more power, on pump gas, until you get close to maxing out the turbo. At that point you'll reach a point of deminishing return. The only way to know for sure is to try all boost levels and record the performance changes. I'll never understand people getting "tuned" at one boost level and then never changing it. If I couldn't change things whenever I felt the need to experiment and log/test the result, I'd sell the car.

 

So, how much peak ignition timing are you running on 93 octane @ 25 PSI? Is it like seventeen degrees from 6000 RPM on up to redline? Also, are you timkering with cam timing too? Are you running the cams straight up or retarded?

I too always liked low timing and high boost ECU chips for pump gas on the old Buick TurboRegals so I guess it would work on these Mitsus as well.

 

With DSMlink I could run 15-16 degrees on pump (stock 2 timing map basically) and about 20 degrees on race gas. With the AEM I can get away with much less timing. About 6 degrees less. There is obviously some kind of difference between the two systems. I have not yet bothered trying to do any tuning on a stock EVO ecu yet, so I can't provide any comparison there.

 

Ok guys. Some update on this...
Spoke to tuner, he is running 1.5bar (21.72psi) BUT seems that he cant hold boost after 5000rpm, so that 238kw atw figure is at 6500rpm after boost had already dropped from 1.5bar down at 5000rpm.

Im purchasing the HD Actuator that available for this turbo as this looks like it will be the most likely thing to sort out my issue.

So there is a lesson to be learnt, if your stroking your engine, get the HD actuator as you wont be able to run even 20psi due to the extra exhaust coming from the higher capacity engine. Ill let you guys know what happens once the actuator is installed and car is re-tuned. If you think it could be something else let me know! But right now my money is on the actuator as boost is dropping after 5k.

The JUN stroker I have as well revs to over 8K! So im loosing all my top end cause of this!