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Discussion Starter · #1 ·
I just did the very typical 3" DP , front powerlog, FWI , 180 stat, 605 plugs, manually controlled engine fan and a 3.5" pulley . Tune is stock. Before I did this, years back I got a cheezy hypertech used just to raise the shift points and firmness by 25% and eliminate top speed cut out, use it was a DTC reader. That's all it's good for. I have an aerotech gauge and below 4800rpms (shifts at 5800) the KR stays at 0, it climbs up to around 4 between 4800-5800. Same with punching it at 75 mph. Tach flies up to 5000 and I get that stubborn 4-5 degrees. A couple regulars on this sight pointed out that Im no doubt leaning out with a stock tune. This isnt an ongoing project, it took 11 years to get to where I wanted to put the exhaust , pulley, aeroforce gauge on it, so Im not interested in getting into an HP tuner , getting famiiar with it all for a one time use. Once this is straightened out, that's it. I really dont want to go mail order tune because I dont want the shift points cranked up, firmed up to chirp the tires, torque management altered......just that (most likely) fuel mixture issue at WOT beyond 4500 rpms. You'd think in the motor city area there would be a place that tuned L67/L32s (dont care about the cost) but no luck with looking around on Google. If Milan dragway wasnt SHUT DOWN, Id go out there, find an L67 guy and pick his brain as where to go!.
 

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1998 GTP coupe. All stock and rust free. That will change soon.
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I could probably work up a tune based on the DHP 1.0, but leave the trans stock.
 

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Discussion Starter · #3 ·
Thank you for the offer, I appreciate that. It's a cool day here in metro Detroit so I thought Id try to use that Aeroforce gauge more and see what kind of relevant data I could dig up to explain this real or not real KR. I suppose with a proper tune, a 3.5" pulley shouldn't be an issue with the 3" DP , front PLOG, FWI, 180 stat and 605 plugs. I did a 6 second scan (15-65mph) and peak timing advance is a typical conservative stock tune at 13 degrees. The peak O2 sensor mv is 935. I know there's a little more to it but with my upgrades, the 3.5" pulley and 16 ozs of torco (which supposedly raises the 93 octane to 97) it seems there would be no KR at all. It stays at 0 until close the high 4000s rpms to where it shifts at 5800. It peaked when I played back the scan at 2.4 KR. With that sorry ign advance and O2 mv reading with 97 octane, KR seems like it should be 0. For what it's worth, and I know this is old school and maybe irrelevant to a computer controlled engine, I put the DP and pulley on last Aug. After a month,I pulled the plugs and they had a very nice medium tan color on the electrode, porcelin and wire. No pitting, no whitish color at all.

Driving it the past two months in cool weather, 40s-50s degrees, I pulled the plugs again just to see and sure enough it has been running a little more rich because the tan went to a darker brown with just a little black on the flat part of the plug. That wouldnt appear to be lean on an old carbureted mill but I know this is a little more advanced. With 127,000 miles, is this possibly phantom KR? Like I mentioned earlier, with 13 degree of spark advance, O2 at 935mv, 97 octane, 55 degrees outside today and the plugs actually having a little bit of black (but more dark tan) in your opinion, am I leaning out at the 4800-5800 range with that data? I did the MAF frequency scan and it peaked at 10,4000Hz.....I think I got that right. I'm a little new to this whole aerotech gauge. Just got it a few days ago. I know that was a lot of rambling, I appreciate your willing to listen to it. For the record, I have this set up about 5000 miles and it's the first time I used torco octane booster. I should have got the Aeroforce the day I slapped that pulley on.
 

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Discussion Starter · #4 ·
Mr N2O ( I can appreciate that having an old 1986 Old 442 with a 68 Olds 350 that will go 12.50s with slicks and open headers....with no nitrous.) After a pass, there's been several times I was asked "do you have nitrous" or is it a small block chevy"?. Now I know this 0-60 is totally irrelevant to my tuning issue and I almost dont believe this gauge but today , with no wheelspin at 15 mph, it does this 5.46 0-60 with a stock tune? Now if I do have that top end lean out condition and KR is real, I know that needs to be taken care of but I cant see getting much better performance than this with a 3.5" pulley, no headers and no 1.9 rockers. I think that gauge is just programmed to make the owner happy. It's probably off a half a second. Yokohama 740 tires bite good, even on a FWD car at a 15 mph roll. I re did that MAF reading and this time came up with 10,100 Mhz and 9.40 mv on the O2 sensor.
 

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1998 GTP coupe. All stock and rust free. That will change soon.
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without a scanner, it's almost impossible to determine the needs across the entire RPM range, you can't do twitch a snapshot. It's about knowing what the LTFTs are locking in at when performance enrichment (open loop mode) kicks in, and then scaling the MAFF at the right points to provide the needed fuel. a .940 mV sounds right, but having the full picture certainly eases the planning.

As a reference I had a 3.4 setup that went consistently 14 flat in the 1/4 mile, and a 5.2 zero to 60. that was with a solid hookup on a prepared track though.
 

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Discussion Starter · #6 ·
Well it sounds like I’m just starting to scratch the surface and have a way to go in the world of tuning. I suppose ignoring KR won’t make it go away. I noticed just 2.4 of kr doing a 15 to 65 but on the highway doing a 70 to 95 it jumped up to 4.0. After 4500 rpms.if I’m seeing this when it is 55 outside with 97 octane fuel ,I suppose it will just get worse with 75to85 degree temps and straight 93 pump gas. I wouldn’t care if I didn’t get 1 hp more from a tune ,just to get no kr in warm weather with 93 premium. Do you program a pcm in the vehicle thru the obd port or just with the pcm itself? I’m in Livonia if you’re in Mich.
 

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1998 GTP coupe. All stock and rust free. That will change soon.
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im in Buffalo NY, just offering to set up tune by mail based on your setup and common bins available. remind me what year you have
 

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Discussion Starter · #8 ·
That sounds the easiest solution to what needs to be done. The car is a 2005 with the L67.

Just out of curiosity, and this is probably more irrelevant data that you don't need, but I wanted to see exactly what was going on with RPM vs KR. It will scan 2 channels over time and I can play it back frame by frame or just hold the button and see how it changes. I got a clearer picture of what it's doing. Doing a 15-65 mph run, it will max out at 2 to 2.5 KR . The KR starts at around 4900 then when I play it back over 6 seconds, the KR will quickly drop as the ing adv drops, it's back to 0 by 5500 and it shifts at 5800 at 0 KR. Same with the 70-95 run. KR starts to creep up at 4900 then it drops to 0 by 5500, shifts at 5800 at 0 KR. Sometimes I'll get 2.5 on the 70-95 run and the highest I saw was 4 degress of KR.
One weird thing is I tried this with 93 octane and 605 plugs then dumped that 16 ozs of torco in 10 gallons of 93, put the 104 plugs in and I got the same results at 15-65 or 70-95. When going through the scan more closely, the ignition timing actually peaks a 14.5 and the O2 at 950 mv. As long as Im under 4900 rpms, no KR. I suppose you've seen this scenario many times and can take care of it with those common bins. Too bad I have this minor KR because it runs so good but I dont want to fry anything with this stock tune.

I think I mentioned I dont care about torque management, skip shifts, cooling fan on time (have a manual switch for that). The shifts are set at 5800 and the shift firmness is at 25%. I suppose all that will just remain the same? Thank you for your offer to set this thing up the right way. Any special packing procedure to ship a PCM?
 

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1998 GTP coupe. All stock and rust free. That will change soon.
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Rats. unfortunately I can't tune a 2005 PCM with my setup, i'm limited to the 97-2003 hardware with my DHP and offboard harness.
 

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Discussion Starter · #10 ·
Oh well, that's how it goes sometimes. Thanks a bunch for all of your info into what my PCM needs to deal with this top end lean out situation. Between this website, the Aeroforce gauge and talking to people with fast L67s that know what they're doing I'm picking up more and more as time goes by. I may roll the dice with a mail order tune from intense ( I'll just try to convince them to leave the skip shift, hard shift, not messing with the torque management)...leave all that alone and just deal with the LTFT/ MAF, etc and richen it up so knock out that KR. OR, money isn't an issue....maybe I could talk myself into an HP tuner set up and attempt this on my own but that's a tall order for a beginner and I have no plans to drop to a 3.4 pulley, 1.9 rockers, headers or a short stack innercooler.

With the fact that the KR didnt change a bit even after going to the 104 plugs/ octane booster mean anything or am I simply dealing with a stock tune that isn't adequate to fuel that smaller pulley at 5000 rpms plus? A lean out condition at the high end sounds simple, it's just having the equipment and know how to richen it up the correct way. Thanks again for all of you time and knowledge. Man, a stock 98 GTP with no rust ? Not many of those left. This 05 Impala SS I have is pretty clean. Only seen 5 mich winters then I quit driving it. Just some surface rust on the undercarriage. Not many super clean L67 W bodies left out there anymore.
 

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here's a link to the tuning dropbox. chock full of good stuff. check the folder "tuning guides and worksheets" and that will give you some insight into the tuning process.

Dropbox - tuning - Simplify your life
 

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Discussion Starter · #12 ·
Wow ,that's a treasure trove of stuff. Thank you. It just takes me time to read, learn and implement post March 2012. Some drunk punks turned left in front of me, I had the green light and plowed into them. They call it a "moderate traumatic brain injury" but some days, it's not moderate. Put me out of work for 5 months and I work in a technical field. Climate control lab, visteon, now Hanon. I work with compressor test stands and a compressor calorimeter/helium mass specrometer. All computer controlled gadgets, but since then, learning new stuff gets frustrating but I eventually figure it out. It also causes me to ramble and be a little ODC with questions. Id like to ask one last thing then Im done with this stock PCM. Just for grins, I set the aeroforce for RPM and LTFT. -5 until 3700 rpms then it goes to 0 right up until it shifts at 5800. STFT is -5 until 2700 then goes to 0 up until 5800. Just curious is that means anything? Probably just means I have a stock PCM.

Another brain injury goof. I thought I had the 104 plugs in there. I forgot I switched them back to 605s due to the cool weather and the color of the plugs. I put the 104s back in and Im only seeing .5-1.0 KR from 4900 to 5500 then KR goes to 0. Repeated that process 3 times and got the same results. It looks like the cooler plugs made a noticeable difference. However it is 57 degrees out. It reached 2.1 KR at 5000 rpms going 70-95 then 0KR at 5500.

Alright, I think Ive picked your brain enough and am very greatful for the info and especially the Dropbox tuning. Anything to simplify this deal. Now it's mail order tune or keep going and try to learn to do it myself. I suppose it could be worse. I could have KR at light throttle or 6-8 KR at high RPMs that dont go away at 5000 rpms. That's it, last of the brain picking.
 

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keep the 104s in there with a 0.055 gap. it sounds like the LTFT is locking in OK. I could live with 1-2 degrees of KR on a stock tune and 3.5 pulley.
 

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Discussion Starter · #14 ·
Will do. Thank you. The 104s definitely made a difference on the 15-65 mph and the 70-95 run. Yesterday it was in the low 80s so I repeated those runs and wanted to see what KR was up to. With that wimpy stock radiator and the fans running, I could only keep the temp in the low 190s however my KR on the highway run when I played it back on the gauge didnt exceed 1.7 degrees and on the 15-65mph run ( both runs between 4900-5500 only) it was less than 1 degree KR. That's with just 16 ozs of Torco unleaded octane booster in 15 gallons instead of 10 gallons. I thought the KR might be more of a problem with ambient temps in the low 80s but it didn't really change compared to the temps being in the 60s. To play it even more safe, I ordered one of those heavy duty radiators from ZZP to keep those coolant temps in the low 180s in hot weather instead of low mid 190s. With the performance I'm seeing 0-60 (5.70s with 84 degrees outside) and the way the trans shifts, with a 3.5 pulley, I can live with this stock tune for now. Rather than canned tune, IF I change from stock, Id rather have an experienced tuner do it.

I can see where the people that know what they're doing on this forum get irritated when someone asks about slapping on a 3.4 pulley with less mods than I have and wondering if it will work. Maybe when these cars were new with stiffer valve springs/no carbon build up in the chambers, ect,,KR might be more forgiving but it seems that if you want to run a 3.4 pulley, you'd better have headers and or 1.9 rockers or at least headers and know how to tune or get a shop to do a custom tune. I'm quite content with the 3.5 pulley and very little KR. I pretty much only beat on the car with the 0-60 and that's where the KR is less than 1 degree. Not much interest at this point in playing with a 3.4" pulley. Thanks again for all of your technical feedback and your offer to tune my PCM ( plus the drop box files) if it wasn't a 2005. After the HD radiator install, it looks like I'm done with this whole deal and won't melt/cook/grenade anything. I'll just keep close eye on that KR. I have no more questions!
 

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I just did the very typical 3" DP , front powerlog, FWI , 180 stat, 605 plugs, manually controlled engine fan and a 3.5" pulley . Tune is stock. Before I did this, years back I got a cheezy hypertech used just to raise the shift points and firmness by 25% and eliminate top speed cut out, use it was a DTC reader. That's all it's good for. I have an aerotech gauge and below 4800rpms (shifts at 5800) the KR stays at 0, it climbs up to around 4 between 4800-5800. Same with punching it at 75 mph. Tach flies up to 5000 and I get that stubborn 4-5 degrees. A couple regulars on this sight pointed out that Im no doubt leaning out with a stock tune. This isnt an ongoing project, it took 11 years to get to where I wanted to put the exhaust , pulley, aeroforce gauge on it, so Im not interested in getting into an HP tuner , getting famiiar with it all for a one time use. Once this is straightened out, that's it. I really dont want to go mail order tune because I dont want the shift points cranked up, firmed up to chirp the tires, torque management altered......just that (most likely) fuel mixture issue at WOT beyond 4500 rpms. You'd think in the motor city area there would be a place that tuned L67/L32s (dont care about the cost) but no luck with looking around on Google. If Milan dragway wasnt SHUT DOWN, Id go out there, find an L67 guy and pick his brain as where to go!.
I would highly recomend DYNO TUNE MOTOR SPORTS. Brian did my PCM tune and it turned out much better than I was hoping for. MOST EXCELLENT and then some. FLAWLESS! Jake (mr goodwrench) .
 

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I just did the very typical 3" DP , front powerlog, FWI , 180 stat, 605 plugs, manually controlled engine fan and a 3.5" pulley . Tune is stock. Before I did this, years back I got a cheezy hypertech used just to raise the shift points and firmness by 25% and eliminate top speed cut out, use it was a DTC reader. That's all it's good for. I have an aerotech gauge and below 4800rpms (shifts at 5800) the KR stays at 0, it climbs up to around 4 between 4800-5800. Same with punching it at 75 mph. Tach flies up to 5000 and I get that stubborn 4-5 degrees. A couple regulars on this sight pointed out that Im no doubt leaning out with a stock tune. This isn't an ongoing project, it took 11 years to get to where I wanted to put the exhaust , pulley, aeroforce gauge on it, so Im not interested in getting into an HP tuner , getting famiiar with it all for a one time use. Once this is straightened out, that's it. I really dont want to go mail order tune because I dont want the shift points cranked up, firmed up to chirp the tires, torque management altered......just that (most likely) fuel mixture issue at WOT beyond 4500 rpms. You'd think in the motor city area there would be a place that tuned L67/L32s (dont care about the cost) but no luck with looking around on Google. If Milan dragway wasnt SHUT DOWN, Id go out there, find an L67 guy and pick his brain as where to go!.
One thing you can also do is to RICHEN UP THE FUEL DELIVERY A BIT. This will allow cooler combustion. Unless you are looking for max power. One last suggestion, send your info to DYNO TUNE MOTOR SPORTS and they will set you up with an excellent TUNE. This was one of the best steps I did many moons ago and I could not be any more satisfied!

Mr Goodwrench (Jake)
 

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Discussion Starter · #17 ·
Richening up the mixture ,especially on cold days (temps in the 50s and colder), sounds like it would pretty much top this project off however I've just done the exhaust/pulley/FWI/ plugs and haven't dove into the world to tuning. The car is set with the 3.5" and a 3.4/ headers/ 1.9s aren't in my future so it would need just a one time tune . I'd probably go the route of Dyno Brian since his name seems to pop out a whole lot as I read through all these threads. His testimonials seem a more consistent than some of the big name vendor's canned tunes. Thanks.

Mr Goodwrech....that advertising slogan takes me back to the Oldsmobile dealership days of 1985-92 when I was a young punk in my early to late 20s when 3800s were everywhere. Test driving an '85 Old Ciera with a 150 HP SFI 3.8 felt really quick. Also reminds me of Old #3 Dale Earnhardt's black Monte Carlo of that era. Back when you'd pull a smogged out mill out of a G body with (back then) a slushbox 2004R and replace it with a 350 Chevy or Olds/ turbo 350 trans. For the era, the Hurst Olds/442 with the 180 HP 307 HO wasnt too bad and Monte SS with 180 HP out of their 305 wasnt bad . Best things were the 3.73 ring and pinion/ decent handling and lighter weight than the previous intermediates. I can picture that Goodwrench sign in the waiting room at the dealer and Mr Goodwrench with his thick mustache and Barry Goldwater horned rim glasses. Ahhhh, the good ole days.
 

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One thing you could do without a full PCM tune is use a mini AFC. It allows you to richen the mixture based on MAF frequency - it basically re-scales the MAF to trick the PCM into a different part of the fueling table. I used on for quite a few years with great success. you can get one new from ZZP or scour the boards for a used one.

Mini AFC Air Fuel Controller | ZZPerformance

BTW I ran a mild 3.4 setup on stock manifolds and a AFC for a while with blips of KR and had a reliable car that ran solid 14.0 - 14.1 all day long. Don't fall into the "you need IC and headers to run a pulley" trap.

I still can't figure out if "mr goodwrench" is a bot. seems knowledgeable (and a quick google says there is a real person with his credentials) but his responses are a bit tone-deaf at times.
 

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Discussion Starter · #19 ·
I had read some info about those mini AFCs and wondered if that might be a simple fix to richen thing up things a bit at the top end. If you've actually used one with success, I'm more sold on the idea of trying one. I suppose I'm not the only person to even use a stock PCM on a 3.5 pulley with very low KR and good performance.

I noticed that regarding the 3.4 (or even the 3.5 pulley) the responses can go either way. I caught an ear full once with asking about a 3.6 pulley without having "the works" or I'll melt my pistons. Some people will scold you if you dont have headers and 1.9 rockers or a dyno tune, etc for the 3.4 then I see other posts where people run 3.4s 3.5s with much less mods and get real results. THEN I've come across posts where someone dumps $3000 into all that stuff and is still running 14.0? Being somewhat old school, I try to work with whatever seems to work, KR is low and the performance is good. If KR is in check and you're making power, it does make one skeptical as to why so many people push every mod in the book for mild pulleys. I've noticed some people on this forum running well into the 13s with a 3.4 pulley and no headers or 1.9 rockers. The more I look into this stuff, the more it seems like a 3.4" pulley isnt out of the realm of possibility in my car in the future.


Interesting point about Mr Goodwrench. With 992 posts, he's (or a bot) weighs in on a lot of topics. I'm a little new to this whole performance forum thing and have found members all over the spectrum. Anyone using caps frequently/underlining words, repetition, etc , does seems a wee bit unusual.
 

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As someone who started with a 3.4" pulley, 1.0 tune, and basic intake/exhaust items for ~$500, I was running ~13.9 in my GTP consistently enough to win a street bracket class at my local track before. It's all in how people maintain their vehicles and listen to what it needs to run cleanly.

After that, I had a cam-only, non-intercooled, stock heads setup running 12.7's at over 110 on street tires and a slipping $75 junkyard transmission. That's something most people wind up trying to accomplish with all 3 of those upgrades filled-in and more. The range of possibilities is down to how much time/effort & smart application of money you apply.

Throwing a pulley on and not cleaning your MAF or other maintenance can have junk results or make it run like a rocket, but taking care of all your components & systems will put you more to the rocket end of the spectrum more consistently... Especially when you're a poor college kid maximizing the free/custom mods, as well. ;)
 
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