When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Doing some reading on E85 and ignition timing. I think I might be too advanced and that might be why the car feels so sluggish on the bottom end, and why the turbo spools so slowly. The timing and boost in my logs does seem to counter each other.... as the timing drops, the boost picks up. More research to come.
And the part that is often overlooked is that the burn speed, the combustion speed, on ethanol blended fuels is actually faster than what we end up with on gasoline. So if we understand that, what this straight away should suggest is all things being equal as we move from gasoline to an ethanol blended fuel, we may need to retard the ignition timing, start the ignition event later.
Doing some reading on E85 and ignition timing. I think I might be too advanced and that might be why the car feels so sluggish on the bottom end, and why the turbo spools so slowly. The timing and boost in my logs does seem to counter each other.... as the timing drops, the boost picks up. More research to come.
good point, now i remember reading that while e85 will tolerate more timing, it actually makes more power with less timing? Cant hurt to pull timing and see how it does, right? It should be safer than adding timing
I'm going to flash a factory timing map on it when I leave work in an hour, with the top end timing bumped up to around 30 psi. They tested a turbo BR-Z/86 in that article... 4th gear, 2500 rpm and driving in vacuum, a couple degrees less timing made more torque with the E85. 5th gear, 2500 and boost, the car had been knock limited to 18°. Peak torque on E85 was in the mid-20° range though.
They're using a Motec ECU though, which you can make live changes with, versus needing to flash the tune like with HPTuners. We'll see how things go though. There was a significant timing difference between the OE-file and what I was running though... so I'm expecting to see a dramatic change, one way or another.
Factory LSJ ECU only allows the PE ramp to be adjusted with some sort of multiplier. It would be super awesome if I could have it based on the MAP reading. It's basically on a timed ramp based on moment that I got WOT.
I've messed with that a little bit, but knew something else was seriously wrong based on how late it was spooling. I have a feeling the switch to an OE ignition map will REALLY wake the car up on the low end. My previous timing map was cranked up. More definitely does not equal better.
E85 is tough to tune without a dyno. Hitting the MBT is just a guess. Hard to tell when you pass it up since it doesnt knock. Like you said, timing, especially down low, doesnt need to be anything crazy. My Evo dips to around 2-3° on initial spool and peaks around 14°.
Haven't had the chance to play around on a dyno with an LSJ, but Adrian's LNF hit MBT at 24-25* when he was on e85. I wouldn't run a stock timing table, add 3-5* to the table overall and see how spool acts.
Also isn't the PE table rpm based not time based? That you divide whatever your stoic AFR is by the target AFR to get the unit, for example you have a stoic AFR of 9.8 for e85 and you want to target a 8.04 (0.82 lambda) the number in the table should be 1.2189
E85 is tough to tune without a dyno. Hitting the MBT is just a guess. Hard to tell when you pass it up since it doesnt knock. Like you said, timing, especially down low, doesnt need to be anything crazy. My Evo dips to around 2-3° on initial spool and peaks around 14°.
That's basically what I'm figuring out. Sucks even more since I don't think we can actively change timing while running to test for MBT. More of a flash and run again, flash and run again type thing.
Originally Posted by ECaulk
Haven't had the chance to play around on a dyno with an LSJ, but Adrian's LNF hit MBT at 24-25* when he was on e85. I wouldn't run a stock timing table, add 3-5* to the table overall and see how spool acts.
Also isn't the PE table rpm based not time based? That you divide whatever your stoic AFR is by the target AFR to get the unit, for example you have a stoic AFR of 9.8 for e85 and you want to target a 8.04 (0.82 lambda) the number in the table should be 1.2189
I took the stock map and SUBTRACTED 2° from the majority of it, and then ramped it up to about 25° at full boost. I'll play with it some more after work, but I'm basing this off of input from the HPT forum and people comparing factory GM 93 timing maps with factory GM E85 maps for the same vehicles (flex fuel maps, etc). Also, apparently, you can't take typical GM injector data for Offset and plug it in to an LSJ? Injector Dynamics has a specific Excel sheet just for Cobalts. They had to punch it out for me today; they had it for the ID1000's, but hadn't done it for the ID1050X's yet. Hoping that helps my choppy idle problem.
You're right about the PE Multiplier table being RPM based. I was thinking more of the "ramp" setting. I can't think of it's actual name though. I've been in tuning mode for so long, I didn't even think about adjusting my PE Multiplier based on RPM. I've had it as a straight line since the beginning.
That's basically what I'm figuring out. Sucks even more since I don't think we can actively change timing while running to test for MBT. More of a flash and run again, flash and run again type thing.
I took the stock map and SUBTRACTED 2° from the majority of it, and then ramped it up to about 25° at full boost. I'll play with it some more after work, but I'm basing this off of input from the HPT forum and people comparing factory GM 93 timing maps with factory GM E85 maps for the same vehicles (flex fuel maps, etc). Also, apparently, you can't take typical GM injector data for Offset and plug it in to an LSJ? Injector Dynamics has a specific Excel sheet just for Cobalts. They had to punch it out for me today; they had it for the ID1000's, but hadn't done it for the ID1050X's yet. Hoping that helps my choppy idle problem.
You're right about the PE Multiplier table being RPM based. I was thinking more of the "ramp" setting. I can't think of it's actual name though. I've been in tuning mode for so long, I didn't even think about adjusting my PE Multiplier based on RPM. I've had it as a straight line since the beginning.
Oh it's the PE delay table that is stupid, iirc it should be set to zero or near zero so there is no delay between the pedal activating WOT PE fueling
After thinking about it for a bit, I should probably start with the GMS2 Ignition map, as they're more likely to have tuned it closer to MBT than the factory tune.
Maybe I'll just save up all my babysitting money and buy some dyno time one of these days. I would like to figure out how much power it's making anyway... it and the Viper.
Originally Posted by ECaulk
Oh it's the PE delay table that is stupid, iirc it should be set to zero or near zero so there is no delay between the pedal activating WOT PE fueling
Yes, PE delay. I think for the LSJ it's a ratio. I have it sit at 1.0 and my CMD AFR changes basically instantly to my PE spec at WOT. I think a lower number is faster and a higher number is slower. I might work on dialing that in better later on.
Driving home yesterday and the OTTP shifter clamp came loose... Lost 1-3-5. Managed to get it home with 2-4 though. Pulled the shifter apart and took measurements. OTTP and OE shifter ball are the same size. Reassembled a couple different ways, but really only one way worked (the way I originally had it). It looks like there's something that should be providing compression for the top of the shifter cup, but it's not there anymore... or maybe it's the o-ring, but it's old and stretched out? Not sure. I'm considering 3D printing something to work. I tried finding a break down of the shifter and its components, but couldn't find anything in the 5 minute search that I did. Put it back in the car and put Loctite Blue on the OTTP Clamp bolts.
I've been hearing an exhaust leak lately, so I crawled under the car after that. No balance shafts, solid mounts, and high horsepower apparently leads to everything vibrating loose. I found a couple loose bolts here and there - tightened to spec (again) and will keep an eye on them. And then noticed that one of my turbo flange bolts was completely missing. I had a T3 stud kit lying around, but could not get it to thread into the hole... so I'm really hoping the threads in the manifold aren't damaged (I might just need to make sure these are T3 studs, now that I think about it... they might be leftovers from my old DSM setup.......). Also looks like the gasket got blown out, as well (the part that looks like the razor sticking out the side of the flange in the pic). So it looks like I'm going to be pulling the turbo out of the car for a new gasket and studs. I was really contemplating swapping to an LNF setup, but I'm not sold on that idea yet.
Once I pull the turbo out, I might drop the tank and pull the fuel pump housing out to see if I can identify why I've been having feed issues at and below 3/5 to 1/2 of a tank.
This is what happens when two turbo flange bolts back out...
Replaced the turbo gasket and swapped to some ARP black oxide hardware that I picked up from Summit (LINK). For some unknown reason, ZZP decided to tap their turbo manifolds with SAE threads instead of metric. Swapping those bolts was NOT an easy task. Especially the top passenger side bolt, as the CHRA completely blocks access to it from underneath, so it is basically impossible to get anything on it other than a basic combination wrench... and I could only get about 45° of rotation with each turn. My ratcheting combo wrench was too wide, as well.
Got that fixed up and drove the car to work on Monday and Tuesday to work on the tune. Was having issues with the fuel pressure not being consistent at the AFPR. I was starting to think the AFPR likely needed rebuilt... but then on Wednesday morning, the car wouldn't start. Turned the key off... then back on. Didn't hear the fuel pump. Popped the hood and checked the fuel pressure gauge - zero psi. Opened HPTuners and commanded the fuel pump on. Nothing. Swapped the fuel pump relay with the Aftercooler Pump relay. Still nothing.
So I picked up a new AEM fuel pump for the car which should be going into the car some time in the next handful of days (Aug 20-22, most likely). Along with that, I'm going to remove the wastegate, put on some block off plates, and test drive the car without a wastegate just to see if the turbo spool is affected at all. I don't think it will be, but I just want to see. I have a new valve seat and gaskets for the wastegate going on afterwards, as well as a new spring for my Hallman MBC. I'm not expecting that to change anything, but for $2 I felt it was worth replacing a small, 12 year old spring.
Semi busy weekend working on the Cobalt... full of frustration, facepalms, and likely heat stroke. But there was also continual learning... and that is what is important, right??? I'm low on sleep, so this post is going to be extra spicy.
Started Saturday by dropping the tank on the Cobalt. That's a lie. I mowed the grass first. And THEN I dropped the tank on the Cobalt. **** it's hot. Luckily, getting the tank out of a Cobalt is fairly simple. Also, skin contact with ethanol burns... pretty bad, actually. You'd think that someone that owns a bag full of silicone vacuum nipples would be smart enough to cap a loose line after the first time they doused themselves with fuel, but that person is not me. I definitely doused myself a good 3 or 4 times in the process of pulling the tank out... once on the face! And unfortunately, my fuel pump "died" when I had a hefty 8-9 gallons of E85 in it. That's good for building muscle mass. More on the quotes around died later.
Once the tank is out, pulling the housing and pump out is fairly straightforward and easy. I used a 1.5L fluid syringe to pull 20 L of E85 out of the tank so that it would be a little bit easier to lift and put back into the car afterwards. The Holley flexible fuel pump hose that I bought from Summit didn't really fit. I probably could have, and/or should have, hit it with a heat gun to try and slip it onto the fittings... but I really wasn't interested in trying that, so I just went to AutoZone and got a new length of rubber fuel line. ****. It is hot. Did some screwing around with the pump housing and got everything reassembled, then put it back into the tank. I then proceeded to struggle for 15-20 minutes to try to get the tank back into the car by myself. Did I mention that it's offensively hot? Threw some tools around, gave up, and asked my girlfriend for help. I just didn't have the ability to get the tank in position and bolt it up by myself. Took the two of us less than two minutes to get it in. The 3" exhaust actually makes it a bit more difficult to squeeze the thing in since the tank tucks up above the exhaust system, but with the extra person it was so much easier. Finished.
Get in the car, turn the key... and I don't hear the fuel pump. Swap some underhood relays again. Nothing. Check the fuse in the trunk for my fuel pump rewire. It's fine. Think to myself, "**** it's hot. I bet there's a fuse under the hood that I should have checked a week ago when this thing died." There was definitely a fuse under the hood... and I definitely should have checked it, because it was blown. Replaced it and tried again. Still no fuel pump. Deep sigh. Swap the relay on the fuel pump rewire with one from my racecar GTI. And there's the fix! It finally works. Car starts and idles... and almost seems to run smoother than before. I might send the other fuel pump off to be tested... if it's still actually good, then I'll put it in my racecar GTI, since I plan to eventually move to E85 in that car.
Car still doesn't hit full boost until like 4250-4500 rpm though. But that's a story for another day.
August 22, 2021
O M G, it is SOOO uncomfortably hot. Actually the problem is that it is really damn humid... the Google weather app told me it was only 95°F, but that it "feels like" 107°F. Felt more like 107°C to me.
I fired up a brisket in the background and got to work on the Cobalt! Again. The first thing I wanted to do was to test the wastegate and make sure that it wasn't my problem. About halfway through this "test"... I thought to myself that I really should have done this second, and instead should have done the high pressure leak test first. More on this big brain thought later. Sooo, I pulled the wastegate off. It's really ******* hot. Then gave it an inspection. It HAS the valve seat and there is no sign of flange leakage. Valve looks tight to the seat, as well. So I pulled out my grinder and a sheet of metal, then cut out two plates to use.
In the back of my mind... I knew this could go catastrophically bad. Like, really really bad. But, lucky for me, the wastegate was not my issue and the turbo continued to spool as slow as ever. Returned the car home, put my industrial fan in front of the car with the hood up, and went inside to take a cool down shower while the exhaust cooled down. Went back out about an hour later and pulled the block off plates off, reinstalled the wastegate, and started setting up to do a pressure leak test. I had bought a 3" PVC cap from Lowe's to block off the system at the turbo inlet. As an FYI, if you plan to do this, a 3" PVC cap is 3" ID... and about 3.5" OD. I knew this and had a 3" to 3.5" silicone coupler. Jammed the PVC cap into the coupler, slipped it onto the compressor inlet, and clamped it all down. Flip the switch on my compressor, pulled the AFPR vacuum hose off of the I/M, slipped the nozzle of my air gun into a different vacuum hose, and then slipped that onto the AFRP's I/M port.
I gave the air gun a squeeze... and heard and felt a massive leak, blowing right into my face. It smelled heavily of fuel and felt like it was coming from my #4 injector cup. I tried blocking it with my hand in the general area to block it and that seemed to still point to injector #4... when I got my face close, I could feel the air hitting me and it felt like it was coming back from the injector cup. I was about ready to hang up my hat and say that the case was solved... but decided to investigate further; it just felt like a LOT of air was leaking. I tried blocking it with my finger even more... like REALLY get in there... just so that maybe I could block it off and hear air from any other leaks too. One benefit to it being UNGODLY HOT is that when a rush of air blew across my wrist, it felt like a godsend and really got my attention. And then I saw it... barely... but I still saw it.
Big oof. Had my girlfriend sit in the car and read the boost gauge off to me while I tried laying my finger across it. 3 psi is when it really starts leaking... and it leaks enough to hold steady at 5 psi even when I'm pumping as much air as I can into it. Which explains a lot, really. Sidebar, Batman themed Duct Tape will bubble up and leak at about 5 psi, as well.
Well... ****. I always wanted to refinish the intake manifold since the gloss black didn't really fit in well with most everything else being wrinkle black. I guess I'll get my chance now. Sigh. This manifold is kind of **** anyway... it would probably serve me well to just change my setup, but I also don't want to have to deal with my charge piping potentially needing modified either. At least I know the problem now though!
Also you might be better off finding a local tig welder (unless you want to try it) to fabricate one just like what you have only without shitty welds that likely didn't penetrate deep enough or was the wrong welding rod
Eh, it was okay. Things were going great with it until I hit the 165°F internal temp. Gave it the ole Texas crutch (wrapped it in pink butcher paper), but the internal temp still stalled. It sat at ~170°F for the next two hours. It got to the point where it was time to eat... so I threw it on my small grill with some hot burning lump coal. Temp started to rise and was going great... then a couple dudes showed up to pick up parts from the Jetta I'm parting out and I got distracted. Scorched the butcher paper in a couple places which kind of ruined the brisket's crust in a couple spots. Internal temps spiked to 210° (supposed to pull it off around 203°, so not that far off). I'm being hard on myself thinking about the mistakes/troubles... it was still good, but I know it could have been better.
It's funny... the only times I've ever had difficulty with cooking something on the grill or in the smoker is when I'm cooking for other people. If it's just the GF and I... everything goes according to plan.
Originally Posted by ECaulk
I second how was the brisket?
Also you might be better off finding a local tig welder (unless you want to try it) to fabricate one just like what you have only without shitty welds that likely didn't penetrate deep enough or was the wrong welding rod
I have considered that. I could at least have it properly gasket matched then too. The current manifold is a literal hunk of **** with huge step downs from the runners to the flange. I had a ton of issues when it first showed up... TB didn't mount correctly, hole was too small so the butterfly couldn't open - actually ruined a TB in the process of finding that out, none of the metal shavings/danglers were removed from where they punched the metal for the fittings, was supposed to be powdercoated but was obviously spray painted... and shittily too, etc. I know there's a guy on FB making LSJ manifolds that look really good and have been recommended to me by someone I trust - Dyemond Fab. I dunno... we'll see.
Eh, it was okay. Things were going great with it until I hit the 165°F internal temp. Gave it the ole Texas crutch (wrapped it in pink butcher paper), but the internal temp still stalled. It sat at ~170°F for the next two hours. It got to the point where it was time to eat... so I threw it on my small grill with some hot burning lump coal. Temp started to rise and was going great... then a couple dudes showed up to pick up parts from the Jetta I'm parting out and I got distracted. Scorched the butcher paper in a couple places which kind of ruined the brisket's crust in a couple spots. Internal temps spiked to 210° (supposed to pull it off around 203°, so not that far off). I'm being hard on myself thinking about the mistakes/troubles... it was still good, but I know it could have been better.
It's funny... the only times I've ever had difficulty with cooking something on the grill or in the smoker is when I'm cooking for other people. If it's just the GF and I... everything goes according to plan.
I have considered that. I could at least have it properly gasket matched then too. The current manifold is a literal hunk of **** with huge step downs from the runners to the flange. I had a ton of issues when it first showed up... TB didn't mount correctly, hole was too small so the butterfly couldn't open - actually ruined a TB in the process of finding that out, none of the metal shavings/danglers were removed from where they punched the metal for the fittings, was supposed to be powdercoated but was obviously spray painted... and shittily too, etc. I know there's a guy on FB making LSJ manifolds that look really good and have been recommended to me by someone I trust - Dyemond Fab. I dunno... we'll see.
At one point Omnitek (I think that was his username here) had a fab company making some damn fine ecotec parts, not sure if he still operates it or not. There are enough speed shops around you in Texas I'm sure you can find one that would do that for you. What company made it originally?
Interesting. Matt Omiotek. I know he worked for Dave at Werks for a while; didn't know he branched out on his own. I knew him for a while, but haven't kept in touch since GMSC died in 2011 or 2012.
And yeah, I can definitely have something made. I think I'm more concerned with how much I'm going to spend than anything else, especially since I've been considering selling it more and more. It was originally made by a company called "Vulcan Turbo". I think they started with Cavaliers; they made a pretty good ram horn looking turbo manifold, although it wasn't without its faults.
I might look into just doing the Saab manifold. They work and they make power... and that's what's most important.
That's what I'm thinking. ZZP is showing out of stock though. I'm wondering if they're having trouble finding them now. I might check the Facebook later today and shoot Dyemond Fab a message while I'm at it.
In one of the many Facebook car groups I'm a part of, I saw someone talking about their son's Etsy page where they make/sell shifter boots... so I gave it a browse, found one that I thought might look good, and ordered it. I've been running without a shift boot for a couple months now - so I was hoping that it'll finally clean the car up a little bit more.
My old OE shift boot was crumbling and leaving "leather" flakes everywhere, so I took it out of the car and didn't put it back in after installing the OTTP STS.
Those OE staples are a big time PITA to remove. I think it ended up taking me almost 30 minutes just to bend those out and pull them free. They're pretty beefy staples. Luckily the F35 shift boot base is a sturdy piece, unlike the shift boot base for the F23 cars, which become extremely brittle with age.
After that I just needed to do a little cutting, a little tugging, and a little stapling. Office stapler doesn't work all that well unless you can get it lined up with the old holes, which was surprisingly hard to do.
I'm not sure how much I like it installed, but we'll see if it grows on me. I definitely think I'm going to remove it from the top clamp point and just clamp it lower down on the shaft. I don't like it clamped to the base of the shift knob like it is.
In other news, I was looking at my different intake manifold options. I found a guy with a modified Saab manifold that offered it to me with the TB and harness adapter for $250 shipped. I was contemplating that. Josh@OTTP offered me a discount on one of his sheet metal intakes; I need to reach out to him and see if I can get some dimensions and sizes (plenum, runners, etc). I've never been happy with the spool rate on this car, and the more I think about it... it's entirely possible that my current intake manifold is the root cause of that. The plenum is pretty big, the runners are pretty wide, and they slam into a flange that is NOT port matched to the size of the runners - so there's an abrupt neck down. I'd prefer my setup to be more responsive, with good low and mid range, versus having the powerband shifted up, like most sheet metal intake manifolds tend to do. That's a large reason why I'm really thinking about moving to the Saab manifold. More to come on this eventually.
The next item to figure out is why I start getting fuel cut when I'm at a half tank or less. I know it's the fuel pump... but I don't know why. The car doesn't lean out... it just cuts completely, like hitting a brick wall.
I found out that this is apparently a fairly common issue for high horsepower LSJ's that have aftermarket pumps and run E85. I'm not interested in dropping my tank again any time soon, but this is something I'll keep in mind if I absolutely have to drop it again. One person solved it by cutting the bottom of the pump housing out and running a Holley Hydramat.
I'm also on the hunt for a Saab intake manifold. I'd prefer to pick one up that's already been modified by ZZP, but have been eyeballing OE ones, as well. There's a clean one on eBay for $100 or so... might check local junk yards before buying one though.
Made a run to the Pick-N-Pull on Saturday and they had just about everything that I needed.
Pulled a 2.4L Throttle Body off of a G6, intake manifold from a 9-3, and an electric power steering pump from a Volvo S40 (for my GTI).
Drilled out the LK9's 6mm bolt holes to be 8mm bolt holes and then cleaned it up a bit. I need to figure out how I'm going to mount the MAP sensor and if I'll be drilling and tapping to put in a larger fitting for my brake booster.
Everyone seems to drill and tap new holes or weld on plates to the back side for the MAP. I have to assume that an adapter for the existing MAP hole isn't as practical as it would seem. I'd really like to wrap this up semi-quickly and get this thing on the car. I'm curious to see what kind of difference it'll make. I have a feeling it's going to make the car much more lively and fun to drive (compared to only being a highway car with basically no torque below 4000 rpm).
Especially the top passenger side bolt, as the CHRA completely blocks access to it from underneath, so it is basically impossible to get anything on it other than a basic combination wrench... and I could only get about 45° of rotation with each turn. My ratcheting combo wrench was too wide, as well. 
