Same Stuff You've Heard For Years.. but,

[gnman87]

again.. thanks

for the help.

I have NOT done a leakdown test.. although the mechanic that did the crank and cam may have. We also did a roller timing chain at the same time.

I have NOT done the fuel filter since I've had it.. but, there seems to be no restriction in fuel pressure. That may not matter.. and I'll order a filter now.

the pump is hot-wired.. but, I'm guessing it's the stocker.

I'll get more info.

jp

 

[gnman87]

okay..

a little confused.. the o2s should be high 700-low 800 even WITH alky? Some say only egt works to tune alky as the o2 really can't do the job with that added octane and temperature.

What do you guys suggest with the chip. Again.. I've got a few options..

97 octane Thrasher
22* alky chip
or seven position Casper's?

 

[GN HEAD]

I can understand your frustration....bought my '87 GN in '90, and I finally reached my goal in '04...I hit the 11s. I was ready to sell it too, until I got slicks, the right slicks 28" tall, and got serious about the tune. I spent several years throwing money at it and trying to "shade tree" the tune....you can't do it, not with these cars, you have to have a scan tool and do the "spring cleaning" to a "T"... New plugs was an excellent suggestion, as was the fuel filter and turn down the pressure. Is the fuel pressure increasing with the boost, pound for pound? If not your fuel pressure regulator might be a problem. You have to have the good octane, or alky...you might try just high octane and no aky first, to eliminate other variables that might be holding you back, but you need a good baseline tune. The stock turbo can get you a long way, I would hold off on that till you get it running better, but it is probably the largest restriction you have in the system now. I have, and still do have a problem with wheel spin knock, at the track with traction, the knock goes away, track time is golden for tuning and it takes time at the track to get it right....... Over the years, I have learned that they are "A patient mans car".....and that is an understatement.

 

[bison]

a little confused.. the o2s should be high 700-low 800 even WITH alky? Some say only egt works to tune alky as the o2 really can't do the job with that added octane and temperature.

What do you guys suggest with the chip. Again.. I've got a few options..

97 octane Thrasher
22* alky chip
or seven position Casper's?

I tune my cars as well as my friends cars off of an LM1 datalogger. It uses its own wideband O2.I usually shoot for around 13.0-1 air fuel ratio. I start richer and lean it out till I see peak power. If you use the factory style O2, it will be a lot less accurate and will only give you a general understanding of air fuel ratios. The data transmitter(typically a scanmaster) often wont update fast enough to see if you have lean spots. You need to get samples several times a second for optimum tuning. I have never had a problem with sensors until leaded gas was thrown at them. Never a foul out from methanol in my experiences. Check and make sure all your grounds are good. You could get odd misfires and knock if there is a bad ground. Im still curious about the resistance of the wires you are running. I have seen a lot of knock caused by faulty ignition wires that were not easily detected by looking at them.

 

[gnman87]

Magnacores now

but, they've been on there since I bought the car. I have no problem doing them and the plugs.
jp

 

[turbo2nr]

I tune my cars as well as my friends cars off of an LM1 datalogger. It uses its own wideband O2.I usually shoot for around 13.0-1 air fuel ratio.


WOW. That's lean for WOT. Now, that's very lean if you are spraying alky. I would aim for 11:1 or even richer while spraying alot of alky and high boost.

Anyone else?

 

[Fuelie600]

for the help.

I have NOT done a leakdown test.. although the mechanic that did the crank and cam may have. We also did a roller timing chain at the same time.


jp

This might be your problem. Are you absolutely sure this mechanic "phased in" ( degreed ) the cam? If so, was it done correctly? I have found cams misground, timing chain gears off, and even the factory timng tab inacurate. Don't rely on the "line up the dots" method. Sometimes you get away with it, But.......... A misinstalled camshaft will kill your performance. Hows your engine temp been since the new cam was installed? HTH, Brian

 

[gnman87]

He's

a very good very thorough mechanic. I've been very impressed with him. The temperature is actually very good.. runs cool.

the car didn't perform great BEFORE this work was done. I'm clearly a tuning idiot.. and have to learn to be more patient. Getting these cars right withOUT alky is hard enough...I think that extra component is really screwing with me.

j

 

[SloGN]

the car didn't perform great BEFORE this work was done. I'm clearly a tuning idiot.. and have to learn to be more patient. Getting these cars right withOUT alky is hard enough...I think that extra component is really screwing with me.

j

well it sounds like to me that you need to get some race gas and a fresh o2 sensor and tune it that way then once you get the tune where you want it. when the race gas runs out don't touch nothing and just turn on the alky system and adjust the alky till there is no knock.

 

[blackstallion]

Yes you do need to tune its not black magic?Theres no big secrects to these cars hell they have first generation obd stuff for starters skip the alky **** for now it just adds and extra variable to the fuel tuning aspect get yourself a denso 02 sensor it will last a long time to leaded gas trust me i have one and its seen more than 30 gallons of straight 116 vp brand and as still a champ only costs 22.00 bucks,get some 110 or 116 make sure you have enough fuel delivery being richer for starters is safer you already have scanmaster so thats good.Start with low boost runs 15 psi check for knock first no knock always means good thing,check fuel proper fuel pressure and check 02 at wot runs,don't worry about the magical 760-800 millivolts just get the knock at 0 and get the boost as high as you can.Once you get that part down then worry about fine tuning the fuel adding more boost will also lean out the fuel somewhat so if your pig rich at 17 psi you probaly wont be as rich 19psi.When all that is sqaured away then throw the alky hell i use race gas and meth injection i have a stock turbo and need the extra cooling.Another thing some cars run faster being richer some faster being leaner it all depends on your car.

 

[bison]

I tune my cars as well as my friends cars off of an LM1 datalogger. It uses its own wideband O2.I usually shoot for around 13.0-1 air fuel ratio.


WOW. That's lean for WOT. Now, that's very lean if you are spraying alky. I would aim for 11:1 or even richer while spraying alot of alky and high boost.

Anyone else?

Thats the leanest i have gone without a lean misfire and race fuel. 12.0:1 is a lot safer for the average tuner. At 11:1 power drops off quite a bit from what ive seen on the dyno and mph at the strip. Then again i run a lot more alky than required to just suppress detonation.

 

[VadersV6]

Its getting off base, and alot of people are just repeating what I said.
Dont worry about O2 numbers. A 750mv reading can be anywhere from 11:1 to 15:1. The stock sensor's voltage curve SUCKS. Like I said,
Look for all those issues I mentioned. Make sure there are NO vacuum leaks (the up-pipe can have a big vacuum leak where the alky jet screws in) and make sure everything is working as it should be. This could take a long time, but its worth it.
With it idling, pull off 1 wire at a time and tell us what happens.
Do a compression or leakdown test with the engine warm, with the ignition module/injector plug removed, and crank it about 10 times at WOT.
Take FP to 42. Given that the Alky acts as a fuel, you wont need alot of fuel pressure anyway.
Turn the alky off.
Install an RJC manual boost controller. This will make the car so much more fun its unreal.
Get boost to 16psi by adjusting the wastegate arm and the RJC boost controller. (just follow their instructions)
Bring timing up if you can, to 23-25 degrees.
Reduce fuel bit by bit until you start getting knock retard. Add a little fuel till it goes away.
Set your alky up to start spraying at 14-15psi. (makes transition really smooth) Turn the voltage knob all the way up to get a good spray pattern.
Get out there with the alky on, and watch what happens to the O2's when it turns on. You may not see a huge difference in O2 numbers, but you wont be tuning with those numbers anyway. You tune for KR and back off, or go buy an EGT setup and tune with that.
Turn boost up to about 20psi.
Jump on it in 3rd gear.
Start pulling fuel until you start getting a little KR.
Add a little fuel till it goes away.
Up the boost a little more, and do this over again.
When you're done, write down your happy O2 number.
Now if your happy O2 number is wayyyy out there and really strange, you may have a mis-timed cam.

 

[gnman87]

it's actually very

interesting to see all the of the reponses.. and how different some of them are.

Let's start with chip, guys. Which one? Jay Carter 22*? Thrasher 97 Octane? Casper's where I can control the advance?

That's really where I need to start.. or I could be tuning to a chip that isn't right for my setup.

I'm taking all of your advice.. but, it varies a bit.

:0
jp

 

[SloGN]

interesting to see all the of the reponses.. and how different some of them are.

Let's start with chip, guys. Which one? Jay Carter 22*? Thrasher 97 Octane? Casper's where I can control the advance?

That's really where I need to start.. or I could be tuning to a chip that isn't right for my setup.

I'm taking all of your advice.. but, it varies a bit.

:0
jp

what ever chip has the lest amount of timing in it so you can tune it without using alky.

 

[SloGN]

Its getting off base, and alot of people are just repeating what I said.
Dont worry about O2 numbers. A 750mv reading can be anywhere from 11:1 to 15:1. The stock sensor's voltage curve SUCKS. Like I said,
Look.

i will agree on that. a narrow band o2 sensor is nothing but a switch so the ecm can see that it's moving from lean to rich. The correct way to tune it with a wide band sensor and forget the stock readings.

 

[gnman87]

so,

where do I get a Denso o2?

jp

 

[VadersV6]

If you plan on running leaded race gas, go for the denso cause it holds up better with lead. But I found the Bosch O2 sensor to be MUCH more active than the Denso. With the engine cold, warming up, I get 50-60 crosscounts per frame. Thats usually when the cross counts are least active. Get all the little things out of the way first. Take boost down to 16 or so for now. Set the cam sensor, adjust the crank sensor, check the coil posts, open the ignition module and see if the epoxy is all melted and sticky (shouldnt be), replace the plugs with some AC plugs that are 2 steps colder (42), get some good plug wires, get the RJC boost controller, fix any possible vaccum leak and replace all the vacuum hoses you can, as well as all the check valves (at least make sure they only blow in 1 direction), make sure the charcoal canister purge solenoid is working and not sticking (easiest to just replace it). Set the TPS and adjust things till the IAC counts are around 20. Mine are about 10-15. Get all this crap out of the way. Get an extender chip and a translator plus. You can adjust and tune SO MUCH with these 2 things. You have total control over everything, and you'll be surprised how quickly you are no longer a "crappy tuner". Then get the new O2 sensor and start doing all the things we mentioned. Dont take 1 guys advise over the other...just take the advise that makes the most sense. I struggled my ass off to get my engine running right, for over a year. I've taken alot of what I learned over that time, and telling you a good order to do things in so you dont waste your time.
Oh yeah..what kind of PCV setup do you have? I would recommend getting a catch can. When my catch can gets full and the intake starts sucking oil, I start getting major knock retard problems. That oil vapor has a very LOW octane.

 

[Just a Six??]

IMO You should email Eric @ turbotweak to get a chip burned for your combo. The generic stuff is fine if you know exactly what your doing but he burns the chip according to the info you supply him. Also the Turbo is definately questionable although as said by others you need to supply some numbers from the scanmaster with fresh plugs, Denso 02 & wires would be a good start along with 112 Race gas & No Alchy! Good for starters as said in many posts! After that tell us what you have found. Pretty straight forward stuff so get back to us with info from your findings. Good Luck!

 

[TurboTnZ06]

Do the heads have any work- such as new valve springs?

I'd make sure the 307 or 340 walbro is hotwired and a new fuel filter is in place. Also, a bigger turbo (TE44 is a favrit), more injector (used 42's or 50's w/ right chips) and do some simple bowl porting of the heads since heads are a limiting factor in air flow.

 

[gnman87]

Some Numbers

Hey guys.. just took the car out. Here are some observations.

line off fuel pressure = 45 -- I don't know why.. but, that's what it is. you're thinking it should be 42?

boost = 19psi -- again.. don't know how it got there.. but, I'm going to crank it down

fp at wot is NOT 64 as it should be.. it's 59..

WOT 02 = 808
WOT KR = 6.1

these numbers are at idle
AF = 08
L8 = 58
BAT= 13.2
INT = moved around a bit.. from 123-135
BL = 92
CLT = 168 after driving for a bit
ATS = 127
RPM = 800
TPS = .44 WOT 4.58
IAC = 51
cc = 107
NAL? = 00

what do you think?

jp