slowfive0

Well as usual, things don't do as they should in "theory"...... Added a homemade ram-air to my Volant CAI this week. That was the only change from the last time to the track other then the weather being a tad cooler today. Temps were 48-50^F, 50% humidity and 29.24" - 29.87". 98% of the runs were at 178^ ECT. I made a baseline hit when I got there and it went 12.32 at 107.42 with a 1.724 60. IAT = 104 - 124 on that run. Swapped on the 90mm TB and changed the scalar value in the tune and went 12.26 at 107.96 with a 1.696 (WHO HOO---1st 1.6!!!!) 60 foot. Based off of previous runs, that should have been a 12.1X in theory but not even close today. Runs were very consistent in the 12.25-12.35 range all day (made 10 runs total). 60's were pretty good in low 1.7's all day with (2) 1.6X runs. I played with different things (air fuel ratio, timing up top and lock up points) and didn't see any improvements to speak of. I ended up running low on windshield washer fluid on one of my passes----wideband went lean and I started getting knock so I let out. I filled the bottle and tried again, but was still getting knock. They system isn't injecting so I have to ck out why, not sure if I blew a fuse or what not. So I had 5 minutes left before they closed the track for the day so I loaded last years tune in it and it went 12.32 @ 107.73 HOT SOAKED!!!!!!! WTF!!! Other then being able to hot lap it easily, the methanol injection doesn't seem to be worth much at all. Maybe a mph. Of course none of you guys told me so already..... I should have listened. Live and learn. It was fun racing though!!! Anyone else hit the track today?

Well, I just bought a LS2 tb from Supersub and will be trying it out tomorrow at the track. I'll keep you guys posted. Thanks.

Hey Eric. Welcome!!! That is a bad ass truck! The moderator on here is in the detroit area as well. Maybe we'll have enough SS members in the area to do a track meet next year ;-) If you or anyone else for that matter is interested, I'm planning on going to Lapeer this Saturday or next (last official weekend they're open) if it's cold. Looking for a new pb. Take care and welcome to the site----great bunch of guys

PM sent

So who on here is a diehard bowtie fan only? I've never had a foreign car hot rod and probably never will, but I do appreciate all forms of hot rodding in general. As far as my choice, I like domestic muscle. My daily driver is a supercharged Silverado SS and I have a 1993 Mustang notchback with an F2 procharger. Wife drives a Lincoln MKT with a tuned Ecoboost. Supposed to be good for low to mid 13's. We'll see in the spring........

Agreed, sounds like the slip yoke.

I'm 40 and have owned my Silverado SS since 2008. Got ride of a 2006 Trailblazer SS to buy it----LOL! Love it and plan on keeping it for a long time. Great truck!!!!

Hey Joe, FYI, I found a link to a excel sheet with some values for different size tb's. It matched what I had at my stock 78mm size so I used the value it had for my new 87mm tb. Worked great!!!! Here's the link in case anyone else is looking for this info: http://ls1tuningguide.com/tuninghelpfiles.php Happy tuning!

Zippy, I'm all ears--lol! You have setup some of the fastest combos around I would value/appreciate any input you want to throw my way I would love to do the 102 on the radix as I'm planning on buying one for my future bigger stroker/bigger blower setup anyways. However, timing isn't good right now for that. I'm thinking that you're right about the blade not staying 100% open and it makes sense thinking back to what my vacuum gauge was doing when I was testing for restriction. Honestly, I think a 90mm tb would put me at 0-1" which would be better and probably sufficient for this combo. I'm not sure a 102 would show much if any difference at this level imo. I've been wrong before though----lol! If you have a part number, that would be great! I need to order one in the next day or two and get the truck dialed in before the tracks shut down for the year. They are only open until Nov. 27th unless there is snow before then. Timing isn't much more aggressive really. Before the truck didn't want to tolerate more then about 19.5^ pulling in 3rd. Now I can carry 21-22^. I'll send you some logs and my tune. Love to get your input----thanks. I always thought if you could stay with the MAF it was better for all around driveability and flexibility to changing weather conditions? I know there comes a point where that is hard to do though. I'm open to the idea if it will help me go faster and I can maintain good driveability (I drive this 365 days a year to the tune of about 20,000 miles a year). I also have a 2 bar map sensor (used with my autometer cobalt gauge) on the truck already. Really? That would be sweet if so. I didn't think I was even remotely close to being the fastest stock wheeled/full weight SSS around! That makes me feel good as I feet that I'm pretty close to maxing out this combo. The tune needs a little work and I have a little restriction on the inlet side still. Mufflers may help.......1.70 - 1.74 60's. I feel if I could get into the high 1.6 60 foots and addressing the other items mentioned, the truck would run 11.90's (in good air). That is my feeling, making it happen is a different story though. From there, smaller/lighter tires/wheels and weight removal would shave some time off too I guess. I guess it would be cool to say I ran a 11.80 or something like that Oh, and I have to throw much love Krambos way!!! He has helped me tremendously as well getting here. A year or so ago, I would have been happy to get into the mid 12's. Sheez.

Thank you Zippy. I'm seeing 98-99% tp during my runs. Used to always be 100%. I thought it was the throttle area scalar setting, but I programmed that with no change. Well it does run better (driveability), but no effect on the 98-99% tp at WOT problem. I wonder how much that is hurting my trucks performance......? Thinking about it further, that makes perfect sense!!! When I watching the vacuum going to the top of 1st gear, it was 0", then would gradually hit 1" near redline, than all of a sudden 2"!!!!! That makes sense if the throttle blade is starting to shut! Thank you! So maybe the 90mm tb would be the way to go. LS7 or LS2? I can get the LS7 for 150, but the LS2 is 200. Thanks Zippy!!! Or maybe the 102? I am planning to do the 427 and the TVS 2300 with spacer + 4L65-e.....

I'm using an 87mm tb that I had laying around. I think it came off of a TB SS, but not positive. I'm also using the x-link. I would like to upgrade to the 102mm tb but $600 is pretty steep right now (I'm building a 7 second mustang). Thinking about the 90mm tb, but not sure if the extra 25% throttle area will make much difference at this point for $200. I'm very tempted though as I ckd restriction and I started out with 4" of vacuum between the tb and the blower (78mm tb) and now have 2" with the new tb. Not sure if that last 2" is the tb or the inlet tube/maf???

Went to the track today (50 degree temp) and went 12.27 at 108 with a 1.7 60 foot. This run was made within 5 minutes of arrival. Made some adjustments to the tune and got the mph up to 109.5 hot lapping it. My IAT's were 105-110 starting out each run and engine temps were 178-180. Most of my runs fell into the 12.30 range as my 60 foots were averaging 1.74 (spinning a little). Not sure how I got the 1.7 on the first pass, but it dead hooked and felt great! Maybe heat in the tires from the 50 mile drive??? Tire pressure was 35psi (LOL!). Near the end of the day, I did lower the pressure down to 27psi and let it cool a little but they closed the track before I could make another pass. Last year in 40 degree air, I went 12.21 at 110 with a 1.7 60 foot. Since then I've added methanol injection, electric fans & a bigger throttlebody (87mm). Plus, I dialed in the tune some more. I want to get this in the 11's, but I don't see it happening unless I take weight out or find some more power....or both! Not trying to be a dickhead, but I think it's kind of gay to run the number so to speak with some little tires (that look really dumb and are never used again except at the track) and pulling out seats, tailgates, sub boxes, spare tires etc. But I don't see myself hitting the numbers others have without it. I weigh 280lbs and with my sub box, amps, heavy stock 20's, etc. my truck weighs 5650 across the scales. I'm sure the shorter/lighter 16" wheels, pulling my seat, sub box and tailgate plus the cooler weather will get me into the 11's, but ^^^ ........I guess I'm being silly...... What is the fastest SS silverado with stock wheels, full weight and radix? Maybe I'm chasing after something that isn't going to happen. I'm miles away from a 11.70 anything at this point---lol! Thanks.

Wow, where do you start. If I read this correctly, the truck initially ran for a while (at idle anyway) but would run rough or misfire at higher rpms......Is that correct? Also, taking into account your other comments about the heat under the vehicle, etc. If I was to guess, I would say that the vehicle either still has some contaminated fuel; did you siphon fuel out or completely empty it out by turning tank upside down and also flushing residue out of tank----also what about fuel in lines? There could also be damage causing engine to misfire. The term "Damage" being used very broadly; i.e. anything from water in any electrical connectors (coils, pcm, etc) or plug wires or mechanical damage to engine. If the engine ingested water, it could/probably would bend connecting rods, etc. I've seen engines that had a bent connecting rod that didn't sound like a diesel----just didn't run right (were basically down on compression in that cylinder----depends on the motor/circumstances). Either way, this vehicle was missing which will cause raw unburned/partially burned fuel to get in the exhaust. The O2 sensor/s picks up the higher oxygen content (unburned/partially burned air/fuel charge) and think the engine is lean. It will add more fuel to compensate causing a rich condition. The catalytic converters are forced to try and burn this excess fuel and depending on how severe this can and probably did overheat the converter/s. Severe enough it can melt the converter down and cause an exhaust restriction. Many times severe enough to not allow the engine to run. Need to determine if engine is dying because of VATS inteference or exhaust restriction. If exhaust, this would have been due to misfire condition. In that situation we would want to find out why it is misfiring. I would start with basic tests. I would look at spark, fuel pressure (mechanical engine condition; i.e. compression) and fuel quality. Spark testers, compression testers and fuel injector noid lights are cheap and available at any local auto parts store. IIRC, the VATS systems will basically shut down the injectors if there is a security event. In other words it will stop pulsing the injectors if someone is attempting to steal the vehicle. Usually, a few seconds after start up IIRC. That would be easy to monitor----have the noid light plugged into one cylinder and monitor when engine is started and when it dies. A scan tool (Tech 2 or similar) can be used to monitor for a VATS system event as well. Also, can watch fuel pressure during event. Need to see if something is dropping out. Fuel source is very suspect and could be very likely as engine runs for a few seconds then dies. In the dealer, if bad fuel was suspect we could try using an alternative fuel source (fuel injector cleaner machine or tool) --- basically bypassing fuel system and using known good fuel source. Compression could easily be checked too. Exhaust backpressure is also checked easily (remove O2 sensor and install tool) if tool is available. Most people don't have tool, so a vacuum gauge can be used as a rough indicator of potential restriction. Install vacuum gauge and monitor vacuum at idle. Let's say you have 17" of vacuum at idle. Now raise rpm to 2000 rpm----your vacuum should increase a minimum of 2". If you have a restriction (exhaust, intake, etc) the vacuum will be lower then 19" (in this example) at 2000 rpm. Usually in cases like this (where vehicle won't hardly run) the vacuum will drop off well below 10" at 2000 rpm. Too many questions at this point so I'm all over the page----need more info to try and pinpoint problem. Good luck and hope it works out for you. P.S. I would take the time (after you get this running) to go through all of the electrical connectors below the water line and make sure they didn't ingest any water. If they did, I would empty it out and flush with electrical cleaner spray. Flood cars are scary as you can get some really weird electrical problems months after the event in many cases (due to corrosion). Also, if you suspect a problem with a connector don't assume it is good just because you don't see any water/corrosion in a connector. The water could come past the wire/weather pack seal on the backside of the connector and cause corrosion at the wire to terminal area (backside of connector basically). Hope that made sense.

156,000 here. These are great engines. I used to work for GM Technical Assistance and I remember when these engines first came out. At that time, GM wanted some engines back (untouched) for analysis. They took a bunch of 300,000 mile engines back from customers (mostly fleet customers) and gave them a brand new engine in return. There were a ton of these engines at that mile range that had never had so much as a valve cover off. Just good maintenance schedules. I'm more then impressed with mine considering that those are mostly supercharged miles (FuelSlut was the original owner of the truck).

Is that the only things that need adjustment? On the ETC scalar, is there any rules of thumb? I.E. increase table or decrease table by 5% or 10% etc???? Thanks Joe! You still interested in going to the track? I'm kind of up in the air. I bought a t-case from GM earlier this year and it's starting to jump teeth! WTF!!! I've never read of anyone having problems with these and I"m having all kinds of problems. I don't get it..... Wish I could say it was from too much power, but there are way too many others who are tons faster then me.......I'm going in next week to have my guy look at it and see what we can do.

Upgrading my j-tube and throttlebody to 90mm. What items will have to tune due to this change? Thanks.

Pm'd u Brian. Thx

Also, does anyone know if I can buy just the four bolt tb flange? Thx

Completely agree but I already have the 87. I'm seeing 4" of vacuum. Wondering if its worth upgrading. Seems like I might get a tenth of so.... ?

Ok, I must need more coffee because I can't find the old threads on this. Which 90mm tb works with these positive displacement blowers? LS7? LS2? ????? Thanks.

Hey guys, Finally, ckd vacuum between the throttlebody and the blower at WOT/Redline and found I have 4" of restriction. Trying to decide if it will be worth upgrading the throttlebody or not as I will have to buy a j-tube or modify mine, buy the throttlebody and the x-link. Lot of money if it's only a tenth. Anyone have similar results and upgrade? Much difference? Thanks.

Not off topic at all. Discussion and learning for all hopefully. Krambo or some of the others could explain it much better then me, but basically what I did was map my run from the time I went 100% open on the throttle until I closed it. In between those points, I would look at the spark map ---- rpm point vs. the cyl air mass (basically the air the engine is ingesting) and evaluate the timing at every one of those points. The latter points of the chart where the blower is going full tilt and rpm is climbing is pretty easy, but the other points were more challenging as they populate different cells all over the map. Ideally, if you could sit on a dyno and run the engine to XXX rpms and hold it there at different loads and add/remove timing to maximize power in those given cells, then move on to next cell, etc, would be ideal. AWD introduces some problems with that-lol! Just try to start with a good map and make sure you're not knocking all over the place. Make sure your fueling is right (not just WOT). In general, make sure your tune is pretty much cleaned up. Also, make sure your timing map doesn't have big gaps; i.e. going from 16 - 25 in the next cell. Try to keep everything gradual. The smoothing feature helps a lot here. Once you have a nice timing map (and tune is safe---no Knocking) as a base, take it to the track or a desolate area and make some hits in at least 2nd if not 3rd and start to tweak your table. Don't add more then 2 degrees at a time. Don't make too many changes at one time, then go retest. Look at your mph increase or decrease and see if your changes helped. If they did try another degree or two. Do this until you see no more increase in mph gain or you see knock. Usually, you'll find a sweet spot and you want to back off a couple degrees before that. Basically, where you seen best performance and not any further above that. Once you get the upper ranges of your map dialed in closer, start to work on other areas like where your launching at and the transition from that part of the map down into the heavy load areas near the bottom. The logging software is your friend and makes it pretty easy to isolate what cell is being utilized. You will have to modify multiple cells at times as the rpm or load value will be in between two cells. In those cases, the computer is just averaging between cells. On the street, I will make a small hit (say a dead stop to just past the 3rd gear shift) and look at the time at the bottom of log file. I'll take that time and compare it the next log (after making another change) and see if it improved or not. Works pretty well. Not very hard because I'm awd. If I was dealing with tire spin, I would probably just get going at XX mph and then wack it. Whatever you do, just be consistent and make small changes. Best to make one change at a time and evaluate your results. I'll be glad to help you out where I can. I'm still have a ton to learn as well. My fuel trims are off around 5-7% and I would like to get them closer to 2-3% but that is another day....lol Your truck is going to rip when you get it dialed in.

Interesting indeed. He has a Roush blower (TVS 1900 I've been told) on a 5.3. Pulley on blower is untouched obviously, but he is running a bigger crank pulley. IIRC, he is making 8psi of boost. Is running an Alky Controls kit with one nozzle spraying straight Methanol. I spoke to AIS today and he was equally surprised. He has done a lot of testing and hasn't seen changes that low like in this situation before. He doesn't think something was right. I looked at the log again and it definitely is right according to what the log is saying. Started at 100^ and dropped to 82^. Weird, maybe a software issue or??????Blower is more efficient, but that doesn't explain it. Plus, Methanol doesn't usually impact IAT's much at all from what I understand. So WTH!? I don't know......

What do you mean when you say transitions? Are you just referring to the chart in general and how much timing it should have in a given area? I'll be glad to help u any way I can. I did try to look at your file that you posted but my version is older or something and it won't let me open it....

ASAP I hope. My kids play football and that sucks up a lot of my time right now. Either way, as soon as the weather starts to cool way down, I'll be out there if I can break free. Crappy thing about that time of the year is only the die hards come out looking for "the number". And since the track is cold and usually hooks for sh#%, most people either leave or don't show so turnouts are light. Then the next thing that happens is they close early because there are only 10 or 20 cars there. Bastards---lol! Last year I had tested a bunch for the first hour or two and was going to let my truck cool way down for that last bonzai pass and then they announced they were closing early. Curious what it would have run if I could have let it sit for a while.