Nuked

iTrader: (9)

I hope that wasnt a shot directed at me Mellon. Because IIRC, you ran the same times as my stock turbo with a Green and cams? I would have to say my sounds cool high boost was good for something, eh?

SQ

Jeff_Jeske

iTrader: (66)

I've found spiking to 25psi on pump is hit and miss. Sometimes its knockless and works as designed other times its too much for the octane to support. The car also reacts different when going to WOT at higher load levels such as higher gear 3k rpm starts or having more weight in the car. Drag racers might be able to get away with this kind of tune but road racers will see inconsistant results.

I like to boost to 21psi with moderate timing on pump gas. I prefer to be somewhat detuned, consistant, and safe 24/7. Here are some old dyno plots of mine. (This dyno reads 10% lower than a dynojet)

Mellon Racing

iTrader: (38)

no it wasn't directed at anyone in particular and for what it's worth, my time was done with a single track visit on that setup and total of 3 runs in 100*+ weather...not exactly ideal conditions. I was adjusting the tune while I was out there and picked up 1mph in each run...I just didn't get much seat time with it out there. the 20g gave me 25-30awhp over the stock 16g on 93 octane and that's why I got rid of it, not very impressive.

JohnBradley

iTrader: (30)

I seem to tune the cars here in the NW that I can directly oversee (IX's anyway) to 25-26psi repeatably without knock even from low roll in on a stock turbo. This is usually in the range of 3300-3700 depending on mods and the overall tune the car has. A bigger turbo makes it more hit and miss like Jeff is saying, or higher overall temps. 21-22psi at redline seems to be the norm for a IX turbo at 7K, though some are less and some are more.

A FMIC is a good investment if you look to do this on a regular basis in a hot climate. Piping and exhaust as you pointed out make an even bigger difference I think because as Razorlab has been showing the turbo has to work harder to maintain the same level of boost because of the increase in backpressure.

Jeff I am in 100% agreement about road racers being better off running more boost and less timing because of the heat load and length of cycle that they must endure compared to a drag car or lightly driven street car.

JB

RazorLab

iTrader: (8)

12:1 AFR on 100 oct? Do you hotlap that tune Jeff?

I agree with being careful on higher boost for hotlapping. I've done a ton of testing on my personal evo on the track with different types of tunes.

I've found the car is more consistant with less boost, richer AFR's and less timingfor hot lapping. I did a couple track days with higher boost and the car got cranky and I didn't like what I was seeing with my plugs. This is with a FPgreen. I've also found that less timing works better on track. Again, from the cars consistancy and looking at the plugs. I think timing is the real killer on these motors on track.

Larger turbos will handle it differently as they won't heat up as much as the stock turbo as they are still way under their efficiency limits.

Jeff_Jeske

iTrader: (66)

^ Yes I hot lap the car with the race gas tune. I'm running more octane than the car really needs.

I expected to encounter a problem with the stock FMIC but haven't thus far. I haven't been convinced that the stock unit is a restriction so I'm battling the demons in my head that continue to suggest I purchase a 3" ETS unit.

RazorLab

iTrader: (8)

I personally think 12:1 on 100 oct is too aggressive for hot lapping but of course different cars react differently. Have you logged the car on track?

Jeff_Jeske

iTrader: (66)

I've logged a few sessions and they were fairly clean. A hint of knock here and there but nothing over 3*. The car is much healthier now than it was in stock form that is for sure. I have the knock check engine light patch so monitor on the fly.

I haven't lapped in extreme weather with this car. If temps reach 100* I'll drop to the pump gas map and continue to run 100 octane. Thats what I did with my 03.

Mellon Racing

iTrader: (38)

I wouldn't think you'd find substantially more power by going to 12.0 over say 11.5 on 100 octane.

it seems like a richer afr and more boost/timing would give better results and be more stable. Have you experimented? of course every car is different.

Jeff_Jeske

iTrader: (66)

Any time other than spool up I would agree with that. But spool is very sensitive to AFR.

Truth is I didn't spend more than 5 minutes on my fuel map. Simply changing boost and adding timing leaned my mixture from 11:1 to 12:1.

During lean spool and at peak tq my AFRs were in the mid 12s. When I brought it back to 12:1 I picked up a few HP but fattening it up more than that cost me.

In the end there no reason to run 11.5 when 12.0 is clean.

EE

iTrader: (9)

but what if 11.5 would allow for more timing advance for example??
that could be a reason..

Jeff_Jeske

iTrader: (66)

I build my tune using timing. I set the boost I want. Set the AFR I want. Then dial in the timing.

I've been tuning this way for years ever since my first dsm. It has proven to be safe and rewarding.

nothere

iTrader: (23)

lots of valuable info in this thread.

this may not fit into that field, but to answer your question, why add more fuel just so you can add timing? you are slowing the burn so you need more timing to compensate, the net result is a draw.

in the end, timing is all about trying to get the peak pressure to occur when it will do the most good. if that means 11.x at x timing or 12.x at y timing... as long as to much heat hasn't created a problem it is a matter of your and your cars preference.

for most of us it may be wiser to go the rich side as it is a mode the mitsu people used. they would error on the safe side. nevertheless I cringe when I hear sub 11s given as suggested afr.

JohnBradley

iTrader: (30)

I have seen some cases of leaner resulting in less knock. I am not sure from the physics standpoint why this happened nor can I add why the car was able to add 3* more timing, nevertheless its important to remember to tune to the car and fuel, not necessarily popular opinion.

Some will like a tune that others will not.

Case in point in the difference of how Tuners can interpret what a car needs. I like to tune for 11.5-11.7 on gas according to my WB. Another tuner that I am friends with tunes 11.1-11.3 on gas. We share MIVEC maps, so that isnt a variable. The same basic setup, we will still trade back and forth who runs more boost and timing than the other.

My car likes lean and timing or lean and boost. Tuner B, tunes a little richer and can get basically what I do (within a degree or 2). Does the 1/2 point matter? Probably not as much as if you were running 10.0 or 10.5 versus 11.0 or 11.5 or leaner.

ixbreaker

iTrader: (3)

ok here's some more eye candy...this was the cleanest pull i could do with ppl behind me in the carpool lane i couldn't slow down much more
should i add more timing...or boost hmmmm...????