Okay, this is for all the stage 3+ guys out there. What boost levels are you running, and with what mods? Is anyone running 20psi without any type of timing retard? Higher? What issues are you running into that are preventing you from running higher boost?

Here are my stats:
- built bottom end, 8.6:1 compression
- Super16g
- Hahn sidemount intercooler

I'm running 15psi and my timing looks fine. It doesn't seem to spike or climb too high. O2's look okay and EGT's aren't at a dangerous level. I'll be doing some tuning to turn up the boost, but I'm not sure how high I can go. Is anyone out there running higher boost than me with about the same mods??

i have the accell 415 cc/min and the S-FMU along with the 16g and a 1G SMIC. my EGT's get dangeriousally high very fast at 14-15 psi. then again, my exhaust system sucks. stock everything except for a crappy muffler. it was OK for N/A, but right now it just doesn't cut it at all. timing looks good though. about 17-19 degrees of advance is the most i see under boost at WOT.

if i'm lucky, i'll have a custom 3" turbo-back exhaust with no cat and a straight through muffler by the shootout. if i'm even more lucky, motofool's clutch will arrive and i'll have that put in along with my newskoolracing "LSD". my car will probably feel completely different - and for the first time ever, i will have top end power.

I am running 15psi with a built bottom end, 8.6:1 compression, 30lbs injectors, S-AFC and, of course, my star stage 2 kit. I'm not seeing any problems with timing, EGT's or A/F ratio.

Damn I hope this thread really takes off because as soon as my car gets back from the dealer I will be ready to crank up the boost. BTW I also have the Howell 2.2L with 415cc, 8.6:1's, #14 cams retainers etc etc etc and the dreaded S-AFC when turboed.

I wanna see what everyone else is running with a similar setup and S-AFC.

Hmmm, I guess I should've added more stuff to my little mod list. I'm running 415cc injectors, S-FMU, and an SAFC. I use the SAFC for very light tuning, no more extreme than -7% taken out.

So everyone seems to be sitting at 15psi. Why? Has anyone tried to go higher and broke or had problems, or is this just what everyone ASSUMES is the max boost level for our mods?

I'm running about 13 psi right now around town. I just abritrarily chose that amount though. I want a bigger intercooler and then I'll prolly play at 15-17psi or so.

I think the reason why people don't go up to 20 psi or so, is that our knock sensors really don't have the ability to communicate issues with timing retard under boost. I guess we all figure 15 psi or so is conservative enough. If I had a J & S Safeguard to read knock more precisely as you might find on a 4g63, then I might chance it. But with big ole S16g and t3/4 turbos, you better have the car tuned right or even a built engine might blow at that level of power. Stock 4g63 turbo guys even have issues with boosting at 20+psi or so with larger turbos given the fuel and tuning required at that level of power.

Most stock turbo guys tune by knock and timing retard. Since we technically have neither, we're somewhat at a disadvantage. When we go into boost, the knock sensor and timing retard doesn't really go to work. It just goes to ~17 degrees advance and stays there.

I have ben running 17 lbs of boost on my HRC stage 2 with SMIC, 8 injector setup and a built 2.0 block. Next week I will be running 17 lbs of boost on the same setup, except i will be running 9:1 compression, crane #14 cams, fidanza cam gears, a new 3 puck ferramic clutch and the newskool slip in differential.

As far as timing adjustment is concerned, I am going to look into finding a way to make the cam angle sensor adjustable (sort of like the 1st gen dsm's). If I can find a way to be able to rotate that sensor on the cam, then I'm figuring that should be a cheap and very effective way to adjust timing. Anyone else have any input on this?

I plan to run 18psi on my car when I get my EIC in and running. 8 inj setup, howell 2.2L stroker with 8.6:1 comp and 44lb/hr injects. I don't know how the timing issue will go though so we will see. I have the crane unit though if I need to pull out some timing.

Ner947: i bet your EGTs get so high because of that sidemount holding ya back. along with the restrictive exhaust also, as you stated. fix that, and get ahold of a good used FMIC, and i bet you will see a HUGE power increase and safer temps.
www.TeamKLR.com
1997 Silver RS
Wiseco 8.8:1 Pistons(back to low compression!)
Eagle Rods
T3/T4 Turbo
Custom FMIC
Greddy Exhaust
440's
Most current 1/8th mile time: 8.3@90mph 2.015 60'(Nitto Drag radials, i suck)

20psi when its not 90 deg out, it drops to 18ish on days like today (92 deg)

Retard isnt used because I got a new missing link so I dont have to use the black box. But as you know I have the opption.

You know my mods...

Brian

8 psi here /w stock injectors 1450 F at WOT all rich, gotta fix that mega rich condition though with FMU disc. I just broke the car in so that's why I'm not boosting that high but I'm running 10.5:1 pistons also.

I could probably raise the boost to 10 psi right now and when I I install my 30lb injectors I"ll probably run 12. i don't wanna run too high due to the hi compression and detonation and stuff. Hehe I'm not that good at tuning :P

was at 9 and 12psi of boost at 9.6:1 ( stock ).. once im built im shotting for 15psi on 881 min and for kicks 18psi ... cant wait..hehe
Michael
99gs (broken) Motor being built now
HRC Stage 2 8-Injector Setup
Fully Built by July 25,2003 hehe
2GNT Member #32

Jason - you're not quite right. Under boost, the knock sensor works just fine and will cause timing to be pulled just as it would if the car were stock. if it "hears" knock, timing it yanked back. Period. The problem is that we have no factory electronic way to tune for FUEL under boost. An AFC causes incorrect load values (lower, when compensating for larger injectors), which influences timing advance to the high side, which causes the problems we have. it isn't that the stock knock sensor can't pull timing under boost, it is that the stock knock sensor can only affect timing to a certain percentage of the overall advance. When your effed up load values dictate 30* of timing advance, there is only a percentage of that which can be taken away given knock sensor input. As a NA car on 87 octane with the ECU seeing everything it can (up to atmospheric pressure from the MAP), we simply don't require much more tunability than that. So, 30* of timing advance, 15psi of boost, and 93 octane... sure, your knock sensor might scream until its hoarse, but there is only so much timing as a percentage of total advance versus load% that it'll take out.. which can leave you in a dangerous situation. It's not programmed to do more, because as these cars are stock, there is next to no way that the kind of sitation that would call for more tunability than it already provides could occur. The sitatiuon you're thinking of still occurs, but the real reasons behind it are a little different than you think.

Take it with a grain of salt.. I'm no engineer, nor am i an expert in tuning the internal combustion engine, but i've watched parameters change through my logger as i drive a lot, and i've picked up on some of the relationships between them. I understand how the system works to a degree, so i'm extrapolating operations through my emperical observations.

And anyway - i run around 15psi daily. SOmetimes more. I don't look much. My fuel system consists of 440cc/min RC injectors, a 3:1 FMU, and an SAFC. I could get more out of it, but its already made 302wHP, and 302wHP with a 3.55 final 5speed trans is fuckin scary.

i plan to run 15-20 psi's via s20g on the built 2.4

DWAYNE H


whttp://hayabusa.bikepics.com/suz-gsxr750-01-bikepics-13445.jpgww.gottude.com
Red/Black/Silver 01 GSXR 750
Lots of Apexi components...

I'll be running 15psi on my big16g on Monday when I install it. But after I get bigger injectors next week i will be running 19psi daily.
I have safc,walboro 255 and supra smic.

Hey Dino-

I see. I understand your message as far as timing being retarded according to various inputs (load, MAP, knock), but wouldn't the largest input, or the one with the most influence be the knock sensor(as it seems to be the case with a 2g 4g63). I guess my question then, is, given my above assumption, what is the difference or similarity in timing retard according to knock relative to a 4g?

I mean, after reading their timing escapades, they can have their timing advanced or pulled (on a 2g) anywhere from 20+ degrees down to 4-8 degrees, depending on their state of tune. Am I being overly critical of our ecu's ability to pull timing according to knock because I never see advance on our cars stray at all from 17-19 degrees of advance under boost?

Thanks!:thumbsup

I boost 15 most of the time, and I also boost 20 when necessary on the streets. Although I have built internals, Accel DFI, 625cc injectors and Crane ignition with timing retard, I'm still careful when it comes to boosting higher than 20 psi because I don't have a datalogger yet. Theoretically, I should have what it takes to safely run 20+ psi, but by not knowing the uncertainty (such as, my engine timing, knock counts, etc), I have to be careful.

I don't really want to start breaking things by trial and error. Also, any fully built and tuned car will break if you constantly pound on it. I boost 15 psi daily, but with the flick of the switch, I could boost 20 psi on pump gas:D

I was boosting 10psi daily on stock internals. 9psi in hot summer and up to 12psi in freezing temps. I usually had 17 degrees advance in 3rd gear and it dropped to 15 degrees advance at high rpm. This is also when my egt would go from 1550-1600. I have also did this on a flat road then transitioning to a hill climb while pulling in 3rd gear. My spark advance would go from 17 to 13 degrees advance. Egt would climb faster than normal(flat road) and I would hit 1600 egt about 1K rpm sooner.

I believe the higher load in combination to getting some knock caused my egt to climb and spark advance to retard. I have also seen spark advance as low as 11 degrees advance in hill climbs in 4th gear. This was at roughly 5k rpm and my egt definately went over 1600 then. I only did this a couple times for datalogging. Not really smart.

If you tune the car where you never go below 15 degrees advance and not above 20 degrees on pump gas, you should be fine IMHO.

In some high outside temps(98F high humidity) I even did some flat pulls back to back(heat soak the intercooler) and got an average 15 degrees spark advance. It went back to 17 advance when it cooled back down. Later that evening(same road 80F)I saw roughly 19 advance through my pulls.

I plan on tuning for 1500 egt max, no lower than 17 degrees advance and roughly .98 O2 voltage. This is on 93 pump gas. If you guys that have higher compression turbo motors(10.5) turn up the boost, keep an eye on spark advance and make sure it does not drop below 15 degrees advance. I would also keep it running on the rich side. 1450 egt on bump gas might be something to consider. Our dsm tuners have a rule that they never go over 1500 egt on pump gas. I did not listen too well as I wanted to push it to the edge.

Just some datalogging info from my car.

I'm currently running about 12-13 psi, 310cc injects, 1st gen SMIC. On long freeway pulls, the EGT's get upto 1600 if i continue in 5th gear at WOT. At the track, it rarely got up to 1550. I will have to say also that if you want to go above this boost level, that a 2.5" turbo back exaust, and a FMIC should be used. I was going to upgrade my injects to start to run 15-17 psi, but I think i will stay right where I'm at now until i can get a FMIC, and get my custom made DP done..I'd also like to wait to see what HRC's FICU is going to be, but from what it sounds like, its only going to get people up to the 15 psi mark...then use the DFI setup after that..

so stock advance is 17.. so if you advance is lower then 17 say 13-14 advance that means you got some knock/ping etc? so you got to little fuel at that point or to much fuel? could someone explain to me what i got to fix if my timing drops a little to low?
thanks
Michael
99gs (broken) Motor being built now
HRC Stage 2 8-Injector Setup
Fully Built by July 25,2003 hehe
2GNT Member #32

It seems that 17 degrees advance is the magic number when boosted. If you are dropping down to 13-14 degrees advance, your intake air temp is high, you do not have enough fuel, octane too low, under a high load or boost too high for your setup. It could be a combination of all the above. Fix one or more and it could solve your problem.

You can increase fuel to lower your egt and thus use fuel to cool. You cannot increase too much as it might not get all burned and create more problems. If you have 1450 or above egt, my guess is it is all being burned.

You can lower your intake temps by having a good front mount with low restriction. This will definately help with knock and increase spark advance to normal levels. I actually got a 2-3 psi gain(less restrictive) in boost from switching from a starion(stock piping used) to a griffin custom front mount and good piping. I then turned it down to what I was running before. This helped drop my intake temps down because the turbo was required to produce less boost(less heat) to achieve the same level going into the engine. It also cooled the air more which helped reduce detonation.

You could try something: Run a mix of race gas(achieve at least 98 octane)and see where your spark advance is. If it goes back to 17 or around that, then you were definately detecting knock when it was at 13 advance.

Question: What was your egt, AF ratio or voltage, what gear and what rpm? Were you going up a hill or strong(20+ mph)head wind? What was the outside air temp and pressure(elevation is fine)?

Knowing these parameters helps paint a better datalogging picture.

Hope this helps.

Question: What was your egt, 1550 max at 9psi of boost on my 8 injector setup.
AF ratio or voltage .93-.98v
what gear and what rpm? around 3-4gear, rpm from 3,500-6,500 about

Were you going up a hill or strong(20+ mph)head wind? hmmm mostly straight roads sometimes up small hills for the freeway.
What was the outside air temp and pressure(elevation is fine)? im not sure range from say hot to +1 hotter hehe.

i got a hrc fmic, nothing blocking it really, got a cold air intake i made.. hmmm... overall it took me a while to get my 8-injector tuned good, i started rich then went down till i got a little lean, then richen it up a little. now im thinking i should add extra fuel overall? well when im on the road again i will have 881 compression so i guess i got to start over again.?
thanks

Michael
99gs (broken) Motor being built now
HRC Stage 2 8-Injector Setup
Fully Built by July 25,2003 hehe
2GNT Member #32

I think people will call me a biach. Being how I'm stage 3, and still running around town with 5psi, on RC 270cc, SFMU (3.62"), RSR 2.75" catback, and chill with a side mount.

My EGTs numbers are 1400-1500 at WOT, and a/f of 0.96-0.99. I need to lower the rise rate. Maybe go with the 2nd disk.

Not to really stray away from the original subject of this thread, but for those who have a datalogger, or have logged your car a few times, so the timing advance is about 17-18 degrees, and with higher load it drops to about 14 degrees? This is assuming that you have a Missing Link.

kaiser, karl and i was were just talking about you yesterday. you are a little bitch .. hehe... you did not get the full effect of a stage 2 before, now your even slower then before hehe.. j/p dude.. turn up the boost you bit*h.. dude...
Michael
99gs (broken) Motor being built now
HRC Stage 2 8-Injector Setup
Fully Built by July 25,2003 hehe
2GNT Member #32

If you don't see it stray, it's probably not knocking.

I've logged cars that were knocking like all hell, you could hear it, and the timing never went below 13-14*. The whole point i was trying to make is that our ECU will only pull timing so far, because it is not programmed to compensate to the degree necessary in a stock turbo car. It most certainly will pull timing if it gets a knock input, although it may not be able to retard enough to save your motor.