Getting ready to start up the new 305 and I was needing to know, What wire do we unplug to set the base timing. What is the best base timing to get the car going. I do have a custom chip in the car.


Brian Felts

------------------
1989 Camaro RS
305 TBI in process of Rebuild

 

The wire is tan with a black line. It should be a pretty big clip sticking out of the wiring harness over on the passengers side. Stock timing is 0 and that is where you should keep it if you have an aftermarket chip and want to run 87. Maybe you can get away with a little more timing but I'm not sure, try it. Most people with a stock chip advance it to about 6-8 base. This is good but I don't know what your timing table looks like on the aftermarket chip. My advice would be to set it to about 8 and run with the good stuff 92 or better. If it pings, turn the base timing down a bit etc.

------------------
, Jon (350 TBI!)
91 Red My website

 

JPrevost,

I have a Jet Stage 2 and I advanced the base timing to 4 deg. BTDC. Is the only real way to tell how much you can get away with, by listening for engine knock? I do run 92-93 octane fuel, but soon I will go with 87 or 91 due to prices (of course). Should I go back down to zero as a baseline test and go up from there?

Thanx

------------------
92 RS w/t-tops 305 TBI Auto.
170K miles and don't burn a drop o'oil
-K&N Truck filter #1500 w, open ele.
air cleaner
-Dynomax 2 1/2" cat-back
-B&M TransPak
-Jet Stage2 Chip
-180* T-Stat w/ 185* Fan Switch
-JVC CD--Alpine speakers & 4ch. amp
Rockford 2ch. to 2 MTX 12" subs

 

"listening" for knock with a GM ECU and stock PROM is the worst thing you can do...

First off, if you are not having severe knock, ie, not audible, the ECU will retard the heck out of the spark (like it does for any knock with a STOCK CHIP), hurting performance AND mileage and you will never know or hear anything!!!!


You need a scan tool to check for KNOCK COUNTS. Advance until you just see some, then back off until it just goes away and you are as good as it gets. Make sure to do this with the type of fuel you are going to run on a regular basis. Ie, don't adjust on SUPER when you run REGULAR on the highway trips or you'll shoot yourself in the foot...

 

If you don't have a scan tool you could use a timing gun and watch it. I know there is no load on the engine so this isn't a sure way of checking for detonation but it still is better then guessing.

------------------
, Jon (350 TBI!)
91 Red My website

 

Yes I did use my timing gun that has a dial on the back to show the amount of advance. You don't have to get mad FastBroker. I know not to switch gas before I change the timing or vise versa. It's just that I have had many older hi-po cars, and that was the only way to know when you had spark knock was with your EAR!!!!! No knock sensors back then, ya know? Does the knock sensor detect knocks before my ear can? Is that what you are trying to say?

The main reason I ask is because I gave the car a tune-up and read in the Haynes manual not to mess with the timing. So I didn't. Well I know that anytime you change the cap and rotor, that you should check the timing due to minute changes in the parts. My gas milage went way down and so did my acceleration. It wasn't until about 2 mos. later that I read on here that you have to unplug the brwn/blk wire to do it. So I checked it. It was RETARDED about 3 deg BTDC so I changed it. I still am only pulling about 30 deg. TOTAL timing at 4000 RPM. I don't wanna push my luck, or "shoot myself in the foot", that's why I asked. But any V-8 car that can't run at 30 deg total timing on 87 octane is screwed anyway, right? And I don't need a lecture on compression ratios due to combustion chambers and head gasket diameters, etc. I know they're 58cc chamber heads, and all that.

Will just a regular GM scanning tool work or do I need a dedicated scanner that hooks up to the knock sensor? Help, don't hinder.

 

Please do as I said. Checking with the vehicle parked with a timing light will be the biggest waste of time for you this year.

There is NO OTHER WAY 2 DO IT RIGHT but the way I described above!

c'mon, U all know it!

EDIT: if U think I am mad U R wrong. Just trying to help. again, I have been building hot-rod engines for 20+ yrs.

You STILL (with old "hy-po" engines) cannot know if you have mild knock until it is too late and down the road a bit. yeah, any jackhole can hear major knock but what if it isn't loud enough to hear? Glad you never found out... Glad you weren't in a high compression high HP/TQ motor, either.

[This message has been edited by FastBroker (edited May 24, 2001).]

 

How is checking the total advance such a waste of time?
Many of us can't afford a scanner tool. It's just out of the budget right now, I don't even own my own timing light. So is there a way to check if the knock sensor is detecting knock without a scanner? How about something that will tell me if the ecm is retarding timing!

------------------
, Jon (350 TBI!)
91 Red My website

 

Will you please answer my question. I was not really accusing you of being mad. It was just a sarcastic statement. I put these( ) on my message for a reason. I was just joking. I'm sorry. My question was which type of scanner do I use? I have built engines of high TQ/HP and high compression. Unless you don't consider 11.5:1 high. No it wasn't 13 or 14:1, but it got the job done with what money I had. It was enough to push a 72 Nova 13.28 through the 1/4 mile on street tires, an open rear end, and 3.36 gears. Unfortunately I had to sell the car for personal reasons, so I never got to finish it. Just because I have a lack of experience with computer controlled cars, don't assume that I know nothing at all. If you would just advise me on which scanner to use, please. How much do they cost? Where could I get one? Can I get one? Do I put the car in drive, or in park so it's under a load? The confused face was on there because I don't know what type of procedure to follow.

I think you misunderstood my last post. NO, I don't know a lot about knock sensors. NO, I may not have as much as experience as yourself. I was only describing how I was taught to adjust timing when you don't have a lot of money for scanners and such. But that does not diminish my desire to learn more. I was, in no way, questioning your skills or knowledge. I also want to know how to do this stuff. The only way to find out is ask. That's all I am trying to do.

Again, I apologize. Just please don't make personal statements like "Glad you weren't in a high compression high HP/TQ motor, either" or "jerkhole." You know as much about me as I do you. I guarantee I will never make personal, ridiculing comments about NO ONE on this web site that I know nothing of. I have no right to. I mean JPrevost recommended that the guy start with a base timing of 8 deg BTDC. I only have mine set at 4. Why don't you ridicule him? (Don't take that personal J. ) I mean, IS 30 deg. TOTAL timing too much? Do you think it is, do you know it is, or are you just not suggesting anything?

Please Help?

AJ


[This message has been edited by AJ_92RS (edited May 24, 2001).]

 

AJ, you'll have to overlook FB sometimes. I think he gets this Pablo syndron when the stock market isn't doing what he wants it to do.

FB, J/K I hope you don't take what I said personaly. I think we all on this board respect your knowledge and experiance. I know I do. I enjoy tapping into it when needed.

Steve

 

Fastbroker you need to turn your ego down about 5 notches. I don't give a damn about your 20 years. You come across like a know-it-all. You can stop the condesending remarks now.

 

Das Cool. I know that he won't have to get on a roller coaster to get a wild ride, the market seems to be doing that just fine right now. Anyway, I'm just trying to find out how to do stuff the right way. To me there is no other way to do stuff, IF you can help it.

 

--------------------------------------------------------------------------------
Sorry if I'm coming off hard but it's late and everybody needs to sleep this off. FB, you came off a little hot, not a great choice of words. As for everybody else, don't jump all over him, he is here to help and what he's saying is right.
I say advance it to 8. Sometimes we don't all have access to scanners and fancy tools, so we come to the board to ask general questions to get an idea for what we should do. From most, even with aftermarket chips, you can advance base to about 8 when running on the good stuff. 4-6 is a safe bet when running on 87. Of course this isn't EXACT but most will agree you shouldn't have any problems. If you want, spray some water into the intake and run at about 2400rpm to clear out old carbon deposits. Sometimes this can help, I've never heard of it hurting. Take it or leave it. You got the facts and I do highly suggest you get borrow a scan tool in the near future.

------------------
, Jon (350 TBI!)
91 Red My website

[This message has been edited by JPrevost (edited May 24, 2001).]

 

How are you supposed to know when you have a slight knock on a non-computer controlled car when you can't use a scan?

 

All I wanna know is which scan tool to use and how to use it? I would love to advance the timing as much as possible without it hurting my car. FB has sparked my curiosity now.

Spill the beans man!!!

 

Keith, MSD makes an Audible Knock Sensor. Self explanatory, I guess, and they also make the Adjustable Timing control, which, too, is self explanatory. Good stuff and you can make the perfect spark curve (ECU or not) with those tools, if you take the time.


Sorry if I was crabby in that post. No offense meant. I had just found out that my motor is hurting from the dyno thrashing I gave it with the XE250. Got a little too hot, too. Sheot. Maybe I'll put in a HT502 with 670cfm TBI instead. that'll move a Wrangler faster than the 350, I bet!

Again, sorry for the crabiness. I won't mention 20yrs again. later. Have nice long weekend ALL! Even Brent!!! It's all love


EDIT: Thanks for the Support, Steve, just saw your post above. Have a great weekend!!!!!!!!!!!!!

EDIT2: Everyone here knows someone with a scan tool or knows someone who knows someone else with a scan tool... Beg/borrow/steal or even BUY one. Hmmm, use a computer to diagnose a computerized system??? makes sense to me!



[This message has been edited by FastBroker (edited May 25, 2001).]

 

I got the plans off a Grand National web site to build a audiable knock alarm that taps into your existing system. Works well. Sorry, cant remember the specific web site off hand.

------------------
1988 T/A,
9" Ford, 3.50 gears, Auburn posi, 700r4 -w- 2100 converter, 360ci, 9.8:1 cr,
AFR 195 Heads, Weiand #7525 intake, Lunati roller 219/227, .479/.480, 112 LSA
Holley 700cfm 4bbl on TBI truck 7747 computer and chip by Howell-EFI

 

Thanks FB. It's just that I had never heard of one. Trust me. If I would have known that I could buy one myself, I would have by now.
I was not trying to be **** retentive either. I just can't stand it when people (not you in particular) would rather critisize what I say or do, instead of helping me.

That's all. Thanx again.

AJ

 

Dan, can you PLEASE find that link to making an Audible Knock Sensor. That would be really awesome. I've never heard of this before. How much is MSD selling it for and why can't I find it in any of the Jegs or Summit catalogs? Anybody got a part number?

------------------
, Jon (350 TBI!)
91 Red My website

 

I just checked it out at www.msdignition.com Look under the tools link. Then I went to www.summitracing.com to check out the price. AUGH!! $143.00 Part #8964. Das alotta money! I guess it's cheaper than a rebuild though. I am just wondering if you can hook it up in parallel with the factory knock sensor. I guess I'd have to ask MSD.

 

Woah, I adjusted my timing the other day. I unplugged the sensor and used a timing light to set it. I advanced it to 10 degress, I run on the 93 octane gas, I can't hear any detonation or spark ping or whatever you prefer to call it, and it seems to be running alot stronger then it's ever run before, but is 10 degrees too much for this engine??

------------------
1992 RS
305 TBI, Edelbrock Performer TBI, TPI heads, Open K&N filter, SLP 1 5/8" headers, !cat, custom 3" exhaust, Flowmaster 80 series, MSD 6-AL, MSD Blaster GM coil, Accel Cap and Rotor, Accell 8.8 MM wires, World Class T-5, B&M Ripper Shifter, Nitto 275/50/15 Drag Radials, Radial T/A's up front, LakeWood LCA's, Edelbrock panhard rod, Aluminum driveshaft, LakeWood Drag shocks, IROC rear springs, custom interior, etc.

 

That's been the argument for a few days now.

I only have mine set at 4 deg. BTDC. I may be a wus, but it's really the TOTAL timing that you need to worry about. Mine is at 30 deg TOTAL timing at 4000rpm. That's pretty good for me. It may even go up a few more at 4500rpm due to the computer. I don't know. But if it ain't all in at 4000 then screw it. I don't wanna take my chances. I gotta lotta miles and not a lotta money. Oh yea, my car's gotta lotta miles too.

Do you know how to check total timing? If not I'll tell ya how. Usually a 350 can take about 34-38, sometimes even 42 deg total timing without a problem. I had a 72 Nova that took 42 no prob. But each engine differs.

------------------
92 RS w/t-tops 305 TBI Auto.
170K miles and don't burn a drop o'oil
-K&N Truck filter #1500 w, open ele.
air cleaner
-Dynomax 2 1/2" cat-back
-B&M TransPak
-Jet Stage2 Chip
-180* T-Stat w/ 185* Fan Switch
-JVC CD--Alpine speakers & 4ch. amp
Rockford 2ch. to 2 MTX 12" subs

 

It's only too much timing if you are getting KNOCK COUNTS, which the scan tool can check the ECU for.

[This message has been edited by FastBroker (edited June 01, 2001).]

 

Hi; I found the site here

http://www.gnttype.org/techarea/proj...jectspage.html

Hope it helps

 

Yep, thats the one.

 

That looks awesome. I wish I had the time to build it, maybe if it came in a kit form it would be easier to order and less of a headache. That really does look like a good idea. I just got my laptop today so I'm looking for software now. That'll show me the knock counts (if any). I run 93 or better so I don't think there will be any.

------------------
, Jon (350 TBI!)
91 Red My website

 

JP, you don't need 93+ octane with 9.1:1 CR... 87 should do just fine. Just trying to save you some scratch for the next mod

 

FB, thanks, but I just liked running the good stuff in the new engine. It was security so that I got good gas milage on the 540 mile trips . If you look at it, what is the BIG difference between 93 and 87 in price? Not as much as when 87 was under a buck. So I figured I'll run the good stuff until the next oil change then I'll step down a little. I haven't been driving the car much lately so the price of gas hasn't effected me as much.

------------------
, Jon (350 TBI!)
91 Red My website

 

You actually could get BETTER mileage with the lower octane gas with your engine. You should check it just for hahas, but make sure you have NO KNOCK COUNTS with the 87 octane! If your ECU cuts advance, mileage will sufer bigtime but you should not get knock with 9.1:1 CR and 87 unless you have too much advance on the PROM. I'm at like 9.23 and no probs. you'll need a scantool to check for sure, though. later.

[This message has been edited by FastBroker (edited June 02, 2001).]

 

FB What brand of scan tool do you suggest and what different information can it show you? Thanks!

------------------
91 RS 350TBI VORTEC HEADS EDELBROCK PERFORMER INTAKE LT4 CAM AND 1.6 ROLLERS EDELBROCK HEADERS INTO 3" TO DYNOMAX MUFFLER 3:08 5SPD HARDTOP