Something new everyday!

[trading t/a]

Well on Sat I installed the power plate(damn easy compared to a TPI plenum). When I took the tb off and looked down the intake runners I noticed they were port matched to the cylinder head(can see where he scratched the inside of the intake). Upon further investigation I used a flashlight to look as far inside as possible and noticed at the end of the runner(head) it was also ground out and very shiny. So it looks like there is at least a p&p job on the heads. Now I'm starting to wonder if the cam was changed also. Am I right in thinking that the reason I was seeing lower boost when the wastegate actuator was set to stock was because there was less of a restriction in the ports? I have the urge to rip it apart this winter but it runs really good now.

One other thing while programming boost fuel am I right in setting it to a leaner af for spooling? I can run 16-18 psi on the street with no knock(even on the launch and gear changes), but the o2's only go as high as 570mv or so. Some guys say to ignore the o2's and go by the af ratio. Might be time to dyno this mule!

Thanx for any hlp guys.

 

[Murt TTA]

What kind of scantool are you using?? I wouldn't tune for a lean A/f ratio, u might be changing a head gasket soon. Also you are right that running rich will cause slow spoolup. When you are tuning, just pay attention to the o2 numbers and the knock. I usually tune for o2's of around 780 or so at the top of third gear on pump gas, Race gas around 720-750. I never let knock go above a couple of degrees, but i usually get some knock during a burnout, and maybe a few deg during shifts. Keep an eye on Knock retard!! Detonation blows head gaskets!!!
~Murt

 

[trading t/a]

The guys on here have made some great suggestions for me. I don't know what it is, but I can beat the living crap outta this thing and I get no knock. The only time I do get knock is when the temperature is more than 1/4 of the way(usually in traffic) and I lean on it a bit. Even then I only see.5-.7*. If I mix in some Xylene I can turn the timing up to +6* and no knock.

Currently on the street I run -4* and that seems good for 14-16 psi. I haven't gone past 20psi yet on the Xylene mix so I don't know if I'll have to retard the timing a bit more. But like I said I can boost to 20 psi on the xylene with the o2's in the 500's without a problem. I've heard from a few guys that the o2's are useless unless you are using a three wire heated wideband O2.


Anybody else ever had this occur?

Pete

 

[Razor]

Originally posted by trading t/a
The guys on here have made some great suggestions for me. I don't know what it is, but I can beat the living crap outta this thing and I get no knock. The only time I do get knock is when the temperature is more than 1/4 of the way(usually in traffic) and I lean on it a bit. Even then I only see.5-.7*. If I mix in some Xylene I can turn the timing up to +6* and no knock.

Currently on the street I run -4* and that seems good for 14-16 psi. I haven't gone past 20psi yet on the Xylene mix so I don't know if I'll have to retard the timing a bit more. But like I said I can boost to 20 psi on the xylene with the o2's in the 500's without a problem. I've heard from a few guys that the o2's are useless unless you are using a three wire heated wideband O2.


Anybody else ever had this occur?

Pete

Pete O2's inthe 500's is usually a bad O2 sensor....

Ya have to tune using an EGT and/or record your runs with direct scan/turbolink and watch those O2's..My scanmaster when I hit recall may sometimes say 500's for O2's since it records the lowest readings but viewing the same run on direct scan shows a whole nother story where the O2 may have dipped upon launch but steady mid-high 700's throught third gear..

On my EGT,1550 is a good number very conservative for my car.1650'S is more on the edge and gets 2-3 more mph on the top of third.1525 or less the car is rich and not making any power.

1525=790-800
1550=770-780
1650=740-750
1700=720-740

This is my own personal observation..your mileage may vary
Careful how you play with boost...Ya have to monitor it like a hawk or else

HTH

 

[trading t/a]

Razor again thanx for the input. Looks like DS may be my next purchase. Is using an egt probe better than o2's? How hard would it be to set up a gauge in my pod and ditch the knock sensor gauge for an egt gauge(using scanmaster as the knock sensor during a run). Do they have a sending unit inline of the gauge and probe or is it a straight thru temp gauge? If that is the case I may be getting enough fuel up top, just gotta tweak it some more. I do however run too rich on the bottom. Good thing the extender chip lets you adj. the AF during spool up,lean cruise and launch assist. Finally figured that out the other day and I finally can get 3-5 psi on a launch. It's coming along slowly.

I almost get instant boost now I cant wait to get to the track with some boost on the launch. I didn't get boost until just before the 60' and max boost a little before the 1/8. Now it comes on just off idle and full boost less than 10 feet outta the whole.



thanx again fellas...

Pete

 

[Razor]

The meter I use looks like a handheld multimeter..usually it rides tucked under my passenger seat unless i'm tuning,The reason for the digital guage is that it has a "hold" feature whereas it holds the highest number recorded...is it better than using O2's..well if you run race gas..it will skew your O2 readings..not only that..it provides a tremendous backup to the other readings i'm getting from my setup.

I got my meter from Steve S from SMC the guys that sells the alcohol kits.If you do some searching you'll find other sources for the meter...I dont know who Steve gets the probes from..but I tell you its the only way to fly.No welding and just a 1/16 hole into the exhuast below the O2 sensor.

You'll like the direct scan..Get in touch with Bob M from BMcomputersource.com for it..Any LapTop will do..If you want to keep your TTA ECM unmolested get a spare 7148 ECM from and donor car..IE junkyard swap the cal pack chip,mod the case..badabing your done.

Also ya want to really build some boost try this...pump your break pedal a couple times and hold it down HARD...pull up on your Ebrake handle HARD..mash the throttle and wait and see

If your brake pads are nice and seasoned..15-20lbs no problemo..Sticky tires also help this happen..Dont keep the car at high boost levels like these for too long else meltdown of ???? may occur

Eventually move up to using slicks...they work best with our cars..

And this is coming from someone who's gotten a bunch of 1.6 60 foots on Nitto's.

 

[trading t/a]

Thanx again! As for direct scan can it be hooked up to the aldl? Instead of modding the ecm. Also I know the bottom of my IC scoupe id pretty much bashed. Have you ever had exoerience with using a 10" pull type fan mounted on the backside of the IC? Or would it be better to use a push type in front of it. Also I noticed that I was getting some knock at 20 psi with race gas, but absolutely none with the Xylene mix. I think I'm gonna go with that the next time out and try to push 22-25 psi if I can get a few trial runs with DS. Thanx again for the help!!!


Pete