Project Cheap SStreet - 10's for around $2000

[svensk]

What does this Kurt guy know about turbos?

[svensk]

Originally Posted by svensk

What does this Kurt guy know about turbos?

j/k

[carlrx7]

Originally Posted by lt1z

Walter tends to agree with those who give him the answer(s) he wants to hear.

I think it more because I'm the only other one here with a turbo ls2 giving him advice.

Walter,

Change your stoich from 14 to 9.76. You shouldn't need to tweak any ve or one values because changing that alone will increase the fuel amount by almost 50%.

I set my PE up to (1.25) 0.80 lambda then richen it up to (1.28)0.78 over 14 lbs using BE.

-Carl

[lt1z]

Originally Posted by carlrx7

I think it more because I'm the only other one here with a turbo ls2 giving him advice.

Walter,

Change your stoich from 14 to 9.76. You shouldn't need to tweak any ve or one values because changing that alone will increase the fuel amount by almost 50%.

I set my PE up to (1.25) 0.80 lambda then richen it up to (1.28)0.78 over 14 lbs using BE.

-Carl

I do not own a turbo LS2 but have tuned a few.

I have never run 6 degrees of timing on any of them however as I prefer to run a level of boost and octane appropriate for the compression of the motor. I would absolutely not run more then 14 psi on his motor and would start with around 11* on E85 and see what the motor wants.

[carlrx7]

Y'all are stuck on timing like it needs to be a certain value in order to make power. It is just a function of the combustion process. More efficient heads don't require as much timing. As well as high compression doesn't require as much timing either. Hotter iats = less timing because it ignites faster.

[MyLS1Hauls]

Originally Posted by carlrx7

Y'all are stuck on timing like it needs to be a certain value in order to make power. It is just a function of the combustion process. More efficient heads don't require as much timing. As well as high compression doesn't require as much timing either. Hotter iats = less timing because it ignites faster.

6* is too little. Go talk to some well known tuners/builders and ask them how many builds they've done with timing that low. If you have to run timing that low, it is a band aid for a bigger issue...Usually not enough octane and/or too much boost/compression. You want the fuel to burn in the combustion chamber, not in the exhaust port/manifold...If you're not burning it in the chamber, you're just wasting it.

[walleyfisher]

You guys are going over my head on all this tunning jargin, I'm too old school and have never wandered off the reservation of stock LS motors yet.

I was schooled on the classic SB chevy (I have a full roller cammed 355 @ around 425hp) and it likes 36 degrees of total timing, and 5,000 RPM and I couldn't tell you anything about the mixture except after a good pass the plugs all look gray to white

6 degrees seems small
If my compression is at 195 and you add 14psi (induction) does that mean the compression is now greater than 209?

[gn2beatu]

@walley - yes its over 209. Because your compressing air that was already compressed. Thats why you hear terms like static, actual, dynamic, and probably one I missed when it comes to compression ratios. Im not an expert on that, maybe someone else can explain it.

What you guys running for force motor current on the trans. Got it back with the new converter, and it seems to like a little more line pressure to lock at light throttle. Even with the min. lockup at 100%. Stock force motor current is around a 1000, and Im at 800 now, and it locks up allot better, but still has a little slip (200-400rpm) when going up a hill in the lower mph ranges - at like 35-45 mph. Gotta step on the gas almost 40%tps to get it to slip the 400rpm, usualy its just around 200rpm or so. Doesnt slip so much on the interstate, but still maybe a 100-200rpm. Tranny shop owner wants to go for a ride with me tommorow, as he is the one who told me to raise the pressure some. Problem is, at 800 line pressure, it seems to hit 1st gear too hard, even at 0psi at light throttle. Its not violent or anything, but you can hear a light clunk. Goes away at light throttle to a firm shift. Tried slowing the light throttle shift down to .300 instead of the .150 shift time, didnt seem to help much at all. Think I should go back to stock shift times for first gear at light throttle of .500? Any ideas apreciated as always.

[darkhorizon]

Originally Posted by walleyfisher

You guys are going over my head on all this tunning jargin, I'm too old school and have never wandered off the reservation of stock LS motors yet.

I was schooled on the classic SB chevy (I have a full roller cammed 355 @ around 425hp) and it likes 36 degrees of total timing, and 5,000 RPM and I couldn't tell you anything about the mixture except after a good pass the plugs all look gray to white

6 degrees seems small
If my compression is at 195 and you add 14psi (induction) does that mean the compression is now greater than 209?

its 6 degrees ADVANCE, so there is base timing to factor in as well.. I have no idea what base timing on a ls2 is though.

[carlrx7]

Originally Posted by MyLS1Hauls

6* is too little. Go talk to some well known tuners/builders and ask them how many builds they've done with timing that low. If you have to run timing that low, it is a band aid for a bigger issue...Usually not enough octane and/or too much boost/compression. You want the fuel to burn in the combustion chamber, not in the exhaust port/manifold...If you're not burning it in the chamber, you're just wasting it.

the reason you dont see any builds done with timing that low is because they are low compression. dont compare a shop build with this boosted stock engine.

The force motor current is the means that the PCM uses to command line pressure. Force motor current vs. line pressure is an inverse relationship. The more throttle you ask for, the lower force motor current needs to be so that line pressure increases to hold extra torque. Typically, 1.0 amp of current is normal at idle, which is about equal to 65-70 psi. At WOT, less than .1 amp is desired which on a stock trans will make 190-200 psi. The mechanical modifications of the Transgo shift kit will get max line pressure up to 230-240psi.

Factory tunes are very lax on line pressure once the trans gets into 2nd gear. WOT in 1st usually gets force motor current down around .1 amp as it should, but once WOT in 2nd, I usually see about .4 to.5 amp which is about 140-150 psi. If you are making some power, this isn't enough line pressure to make a solid change into 3rd gear. The factory cuts back line pressure once the vehicle gets rolling in order to reduce the drag the front pump has on the engine for fuel mpg gains. A lot of the canned tunes I have seen don't boost the line pressure until the actual engagement of the 2-3 shift, and then drop back to the lax factory line pressure. I prefer to have line pressure proportional to throttle angle across the board. This along with good internals and a Transgo shift kit, will enable the 4L60E platform to hold 600-700hp reliably.

Walter, this is what my trans says about the force motor current.

[lt1z]

Originally Posted by MyLS1Hauls

6* is too little. Go talk to some well known tuners/builders and ask them how many builds they've done with timing that low. If you have to run timing that low, it is a band aid for a bigger issue...Usually not enough octane and/or too much boost/compression. You want the fuel to burn in the combustion chamber, not in the exhaust port/manifold...If you're not burning it in the chamber, you're just wasting it.

Thank you!

[gn2beatu]

Wow Carl, thats allot of pressure. Didnt know they ran that high. Id be nice if there was a force motor current multiplier based on gear. Wish HPT had that feature, would be a nice way to taylor the shifts better. I can seem to run enough pressure at light throttle to lock the verter, and yet shift soft enough for 1st gear at the same time. I know some aftermarket converters need the pressure raised, and or the min lockup raised to make the converter function normally compared to the stocker. Hopefully the owner will have some ideas as well on the mechanical side to improve things the tune cant. If anyone else has any ideas on either locking verter harder or reducing line pressure mechanicaly to first gear so I can raise the force motor current, shoot me a PM, or post it up here. Thanks!

Here is a crappy cell photo of my home made alluminum inserts for the grille areas. I had to loose the factory fogs, so I decided to loose the whole grille. Looks even better out in the sunlight! You cant actually see the pattern well where I took the pic. There is a neat pattern, with holes in it. I cant hold my crappy phone steady enough to show it though.....sigh.

Goona get some LED or thin rectangular lights for the brake cooler areas. If anybody has seen some fogs with actual glass instead of plastic lens (for 100watts) so they dont melt, shoot me a link please.

[lt1z]

Hard to tell from the pic but I think that looks pretty good.

[ssprince]

Def needs a wax job!!

[MyLS1Hauls]

Originally Posted by gn2beatu

What you guys running for force motor current on the trans. Got it back with the new converter, and it seems to like a little more line pressure to lock at light throttle. Even with the min. lockup at 100%. Stock force motor current is around a 1000, and Im at 800 now, and it locks up allot better, but still has a little slip (200-400rpm) when going up a hill in the lower mph ranges - at like 35-45 mph. Gotta step on the gas almost 40%tps to get it to slip the 400rpm, usualy its just around 200rpm or so.

Are you running the transgo converter valve in the trans, or the stock PWM setup? If you're not running the transgo or Sonnax valve, then you should be. Once you run that valve, the lockup percentages no longer apply, as they won't actually adjust the lockup pressure. It is full on line pressure.

If you have the valve in there, and are slipping the converter when it is fully locked, you either have a problem with the converter clutch, a hydraulic problem with the trans, or your tune scaling is throwing off the trans pressures. Put a pressure gauge on the trans and report back what the pressure is at cruise, when it wants to slip.

[PediDr2]

Originally Posted by gn2beatu

Here is a crappy cell photo of my home made alluminum inserts for the grille areas.

Gutter Guard?

[carlrx7]

looks good walter!

[gn2beatu]

@MyLS1 - I thought it had the sonnax valve in it. Would that be in the kit that Brandon from fast put in last year? Right now the force motor current is about 800 from 0-29psi. Not sure on the pressures, but the converter locks much better with it there vs stock 1076? or whatever it is. Went to the tranny shop today, and he said that the 50 miles I put on it is not enough to break in the Kevlar clutch. He prefers to not lock it til at least 45mph, but both the stock and the Yank 3600 had no issue locking at 35mph. So he said put some miles on it, and bring it back next Tue and he will put a pressure gauge on it. I have reduced first gear line pressure to -10psi in the zero torque column and left the rest as it was. But if I go any lower than 800 on the force motor current it clanks when shifting (shifts too hard). I have slowed the shift down to .300 in the 0-150ft/lbs cells for first gear, and that helped some. I guess I could slow it down some more if you guys think that will help some.

@ Pedi - Yup, you guessed it. I have a much better pic to post later tonight. Cheap mod!

[gn2beatu]

Okay guys, finally some good news. Did the E85 conversion, and added some timing in. WOW what a differance is all I can say!! I eliminated the IAT timing reduction completely for tuning so I dont have to worry about running negative timing. Here is where I was at, and where Im at now.

I was at 2 degrees timing at peak torque 4800rpm & 6 degrees at peak HP @ 6400rpm

Now Im at 11 degrees at peak torque up to 4800 & tapering to 13 degress at 6400rpm.

This is all with ZERO knock. To say it woke it up is an understatement. With a 2nd gear roll this thing throws ya pretty good back in the seat. Usually as a driver you cant feel it, but I can feel this, WOW what a differance.

Im letting the trans cool down a bit after doing 3 partial runs. My shift point extensions used to be 4800rpm after shifts NA, now its more like 5300rpm with the turbo. Nice firm and fast ships, doesnt seem to be slipping at all. After 6:00pm tonight, Im goona do some runs if anyone local wants to come check it out.... bring a camera.

And yes, tommorow my signature should be updated with at least a 60', a 0-30 and a 0-60 time, so no whining! I wont post the 1/4 time to keep from pissing certain people off.

Im planning on going to Late Model Throttle next week early if they have an opening to see what she can put down on the dyno! This is finally starting to be fun instead of work.

Last thing I noticed after the E85 conversion was that in the upper RPMs its leaner on the wideband. In some areas it was as lean as 12.8 AFR. I added in another 10% fuel to the area, but only netted around a 12.0 AFR. So I am either running into a FP drop, or the line is too small, or I need to run a bigger wire to the pump. So that will be my next task ASAP. Currently the injector DC is at 85% on the 1st to 2nd gear shift - I was expecting 90% so thats nice to see as well. Leaves me allot more room to up the boost some more in the near future.

[Glocksrfun]

Originally Posted by gn2beatu

After 6:00pm tonight, Im goona do some runs if anyone local wants to come check it out.... bring a camera.

Interesting.. PM time