Earlier thread -> https://www.thirdgen.org/forums/powe...urbo-87-a.html

Very happy to report over 600 miles of driving this past week.. last weekend to Emerald Coast dragstrip in Holt FL.. then up to Dothan Al last night for dyno night at R.A.C.E. and back down to PC Fl to Breakaway where I finally managed a 7.94 @ 87.25! The whole time I was fighting a problem with climbing AFR (into 12.3 territory at 13 psi) even though I kept adding fuel. Not sure if it's something going on with the Megasquirt or something else. When I left 30 mins later, at the same boost and rpm was pig rich at 10.3-10.5. By the way, my dyno numbers weren't so great because of the starting rpm, but the numbers in that higher range were 10% higher than my previous dyno numbers at the same rpm.

Will take a look at my injector duty cycle and see if it is a fuel delivery problem or MS issue.

http://www.youtube.com/watch?v=NWPutRO-bbA

from today's dragstrip runs

 

nice looks like u beat a ls1 thats got to feel good?

 

more then likely u need more fuel pump or bigger lines, i ran into the same issue with my megasquirted turbo v6 car no matter how much fuel i added in the ve map it kept leaning out. put a fuel pressure gauge on it and watched it as i went down the track and i was losing fuel pressure in high gear

 

Project89, it is possible but not likely.. Last week when I first moved the boost up to 14 the car wouldn't turn over 5200. After a few mins we realized the AFR was 10.0 because the tune ramped up as a form of overboost protection for when I was running 11-12 psi. Also last night, after leaving the track, the same tune that was running 11.9-12.3 at 13 psi on the track was running 10.3 at the same point and that was with my wife and daughter in the car.

Something more likely is the fuel filter being clogged. When I removed the original pump, the sock had fallen off at some unknown point in the past. Still, I'm not sure of this either. All I know for sure is that my Megasquirt has some weird AFR issues at idle and now cruise that are resolved by a restart.

 

Joker that was actually my friend's LT1/6 Speed car, but it always feels good to win. The black Trans-am is another friend of mine. He has a Vortec 350 engine with a cam, holley 750 dp, 6 speed, 3.73, 125 shot of nitrous and ET streets. That thing runs good, but considering I'm working with a power adder on a stock TPI and 3.27 gears with an automatic, plus on Firestone radials, I'm very pleased to be right there with him!

That blue truck was a 388, supercharged AND nitrous (which he failed to mention in staging when I asked him about the truck). I know now that my 6.9xx goal is within reach with a mild cam, better heads and a little more turbo. I started at 9.7xx and I'm 2/3rds of the way to my goal without turning a bolt on the internals! And they say TPI sucks!!

 

are u sure the wideband isnt going bad? how much 02 feedback do u allow.ive had only one instance were my afrs would change after a restart of the ms ecm. i fixed it by exporting all my tune files and reloading the ms ecu completly. i.e firmware and tune

forgot to mention check ur iat sensor that will screw with afrs big time if it starts going bad

 

Project89, that is another possibility. I have a PLX wideband and haven't been totally pleased with the gauge system itself, however when it starts showing wildly lean AFR at idle, the car is surging and barely running. Restarting the car then show's 13.5 and a smooth idle (even after the ASE enrichment goes off)

Closed loop isn't (or wasn't) enabled at idle in the past when this was happening. Also I'm in open loop above 150 kpa so no chance of the O2 affecting injector pulsewidth. I thought perhaps the O2 was just telling me it's on the lean side but maybe the engine was actually getting richer, but if it were as rich as it should be at these VE values it wouldn't be able to turn 5000 rpm based on last week's tuning. It had no problem doing that, but it just stopped making the mph. Me best run of the day was 11.3 AFR, my richest run. Everything seems to indicate the WB O2 is working right.

Temps are very consistent on both manifold and coolant. All of my runs range from 90 to 110 degrees (manifold)depending on heat soak at the start of the run. Coolant is always between 195 and 210 degrees. Voltage reported at the MS ranges from 12.5 to 13.1. I thought about running a direct power from the battery just to eliminate current issues. Oh and the AFR reported on the MS logs seem to match what I'm seeing during my passes on my digital gauge within a tenth or so.

I'm getting ready to reflash my firmware on the MS. I'm on 2.1.0 release 20090627, so there were four updates to 2.1 after mine. Plus now they have 3.0.3 20101003 so it looks like I'm 14 releases old! I'm betting there are a ton of fixes for the issues I'm seeing. Did you update to a newer release to fix your AFR issue or just reflash the same back on yours?

 

when i had my issue i just reflashed the same firmware i was using already, but i updated to the newer version shortly after due to a bug that would cause engines to go really rich when going up in altitude when using baro correction

 

Great video, That T/A runs nice too.
If you dont have a stall converter yet. The right one will get you running 7's all day. Keep the 3:27 gears too. IMO.

 

the only upgrades im going to do to mine when i build is siamese (sp) the intakes and cam and possibly heads but im also going to get the compression lowered me and my friend are going to start tearing down the 350 i have and see what im looking at.

 

Yep just went to new Vigilante 9.5" converter, what a difference in the car!

That TA has always ran strong no matter what engine combo he puts in it. Unfortunately the T56 clutch is not happy after yesterday and his last run it was slipping. Automatics FTW in dragracing!

I have on-board video of my 7.94 pass... sorry for the sound quality, that's what I get for using a webcam on my laptop!

http://www.youtube.com/watch?v=AuYKg1uGz-8

Of course the clocks only work about every third pass at this track, and they had to be out for my best run.

 

what rpm did u end up maxing at on the dyno round like 5200?

 

Yep I backed out at 5200.. I need to move forward with my 4L60e conversion so I can get some real dyno numbers starting around 2800 rpm. But first I want to get my paint and interior sorted out. Pretty happy with the 7.94 pass now, so numbers are less important to me for the short term.

 

sounds good man still going to stay black with it?

 

Yep will look like it did the day it rolled off the lot. It has a cheap looking repaint on it, not done in base/clear with crappy body work, along with some new dents over the years, not the least of which was the hit and run sideswipe someone got me with a while back. Also they did not use the correct double stripe around the bottom of the car above the ground effects.

I'm going to strip it or have it stripped to bare metal and make it right rather than to cover up existing paint problems. The interior is in good shape except for seat covers and carpet, so once those and the paint are done, the only thing left would be the finish of the wheels. Not sure if I should sell these and buy some in perfect shape or try to have them refinished somehow.

 

Congrats man, good times so far! Should be more in it!

 

I think so too.. I was right on top of 7.8x, in fact my best 60 foot would have put me there, and really the only thing I did was add about a degree or two of timing. I'm pretty certain my 4600+ rpm timing is overly conservative. From 180 kpa to 200 kpa I drop off about 3-5 degrees for a given rpm. The car feels like it will go 7.6x at this boost level. Still need to get my knock sensor finished up before I push any harder. Of course I told myself if I see 7's I'm happy and done for now, but "now" apparently ended by the time I got home from the strip.

Right now I need to sort out this fueling bs though. I drove it to dinner last night and saw mid 10's AFR at 13 psi. That is a far cry from 12.0 at the track, and I've backed down to a tune I saved during my first hour at the track. When all is working right, it is very responsive to small changes on the VE table, so I knew something wasn't right. I gotta study my data logs and compare the AFR to the map, rpm and duty cycle between various runs.

 

What about an exhaust leak? If you pull in oxy it would run lean. Or rather show as lean.

 

Drac0nic, don't believe so. If I load up the tunes I did Sunday where I was still getting 11.8-12.0 on a pass, today the car shows 10.0-10.3 and leaves a trail of black smoke and will hardly go for all the fuel.

 

Are you letting the MS2 have any authority to compensate for your AFRs? What about something like a vacuum leak?

 

astro if u want to post ur tune files and a data log ill take a look at them for ya and see if i see anything out of place

 

I just switched over to 3.0.3 firmware to see if things settle. So far it's failed the idle AFR problem just like the old version. In fact after lunch I started it up and about 20 seconds later it began to surge wildly into the high 17's. I turn it off, restarted and it idled smooth for 10 minutes at 12.8-13.1 until I was tired of waiting for the surge to show up. Go figure. The only clue is this seems to happen on hot starts, particularly after sitting for an hour or so.

Draconic, yes I have EGO control enabled from about 1000 rpm and up, but only up to 150 KPa. At full boost it is open loop.

Project89 I'll get a copy of that tonight if possible.

 

Oh forgot to post that I changed the fuel filter today. Of course nothing seemed to change with AFR, it's been working fine since I left the drag strip. I'm still a bit on the rich side at 10.7-10.8 at 14 psi. If the filter was the real issue, you'd think I'd have even more fuel now and be seeing 10.0's. But perhaps under certain conditions it was clogging. Who knows.

 

do yourself a favor turn off 02 correction completly just set min active rpm to like 8000 rpms i can almost bet you that the surging will stop

 

Will do

 

updates?

 

I went back to the version 2 firmware. No improvements with the random idle AFR problem and in fact seemed to be a problem right up into the 1500 range. I also disabled EGO below 8000 rpm but no effects on the issue. Also after going to 3.0.3 I had idle surging much worse than with 2. The surging would approach the 18:1 range on the lean side. With version 2 firmware, a restart always cleared the issue but with 3.0.3 a restart was not a guaranteed fix. In fact I did several restarts in a row and it never cleared. If the engine was fully warmed up it was nearly impossible to drive for several minutes after a restart.

So I flashed the latest version 2 bios back in and loaded up my last ver 2 tune. Now it's back to normal so I can drive it.

What I am going to do soon is put 3.0.3 back in and start with a new tune altogether. I will import my VE, IGN and AFR tables individually, but I'm wondering if my old MSQ's are corrupt somehow and bringing the problem over to 3.0.3. So it's worth a shot to start from scratch.

I have data logs but I've changed the tune so much trying to get it to go away I have no idea which tune they go with any more.

 

yeah id do as u say and just import the tables and redo the msq from scratch with the new firmware.i recall a few ppl having issues with the msq's when updating firmware.

im just curious are u using tuner studio or megatune.
i do like the layout of tuner studio but ive always goten alot of msq errors with it so i just stick with megatune or megatunix

 

Interesting trip to the dragstrip yesterday. Car went 7.89 @ 87.72 on a 1.768 sixty foot. Wow at my sixty on firestone radials is all I can think! Anyway I believe the 7.8 pass was the 4th of the day. Things went down hill from there. That pass had a perfect 10.9-11.1 AFR the whole way. The next pass creeped up to 11.3 and slowed. The next pass when 11.6-11.7 and the next pass (the chase one) went to 12's. I did a final test pass and backed out with fuel in the upper 12's! No changes to the tune.

It appears the problem is being caused by the coolant temp. Once the car gets heat soaked after a number of passes and the coolant stays above 200, it's over. Once again, 10 minutes down the highway in lockup on the converter, coolant drops to 185 and the AFR problem goes away. So my very next thing to do is put a resister in place of the coolant temp sensor to simulate 215 degrees. If the problem starts I will know it's the MS - either a bug, the tune or a MS hardware issue. If the problem doesn't happen I obviously have a mechanical issue with the fuel delivery system.

Anyway got an HD in car video of the 7.89 pass and also shot some outside chase car video of an 8.1 pass with my friend driving it.


http://www.youtube.com/watch?v=y7gIDDqGv8c
Shaky cam view of the 7.89

http://www.youtube.com/watch?v=_VCrubANYIc
On board.. I got a little excited at the end so forgive my dance lol

http://www.youtube.com/watch?v=WTVy_UBng6U
My favorite vid.. putting the hurting on my friend's Silverado chasing

 

Good job! car is leaving hard off the line with those tires and no suspension work. What kind of hd camera are you using?

 

Interesting that you would go slower as your AFR creeped up to 12, figure it would be the other way around.

Good times though looks like you were having a blast.

 

That is an incredible 60 on those tires. Good job

 

Nice. I love that last vid. Your car hooks! I like the way the front of your car lifted.

 

HD Camera is a radio shack "Gigawire".. It does 1080p but has a low volume level and terribly narrow angle lens. Not bad for $149 (when on sale) though.

Yep this thing goes a little flat towards the upper 11's AFR.. definitely in the 12's it does. Speaking of the front end lift, I have been noticing lately that my car now sits squatted in the rear and slightly lifted in the front. I'm not touching anything though as this setup seems to work well for traction!

 

everytime i watch ur car launch i pray that when i do mine it doesnt explode my tranny haha. Nice times tho.
BTW have you done any weight reductions at all? or weighed it with you inside?

 

No reduction, only addition! First the weight of the turbo and manifold to the engine.. but then the intercooler and tubing added even more right at the front of the car. I did relocate the battery to the rear. Car is heavily optioned including the Bose subwoofer so it's no light weight. I even have a set of tools in back along with my laptop. Also I've put on about 10 or 12 pounds in the past year LOL.

If I get brave enough to risk the 9 bolt I believe I can pick up close to 2/10ths on some ET streets. Full boost is coming around the end of the 60 foot. Lot of untapped potential off the line.

 

u can change the coolant sensors reading in megatune (resistance vs temp),this should fix ur problem if thats what it indeed is

 

Good idea.. I can just go in and set up a custom CLT sensor profile and make the temp range from 215 to 220.. I'll do that after it warms up enough that it doesn't need warmup enrichment.

 

Wow that didn't take long..

I set the MS up to read a constant 210 coolant temp and a 108 air inlet temp. Car was actually at 175 degrees. ZERO problems, no surging after start and a perfect 10.9 to 11.0 AFR at full boost. This mirrors previous cool weather non heat-soaked conditions, even though the MS believed the engine was very hot. So at this point it looks like the MS is off the hook for all bad behaviour I occasionally see.

So now that begs the question: What in the world is getting hot (with the engine) and then causing lean AFR at full boost and surging/leaning idle. It sure makes the FPR look suspect. I can't easily duplicate this condition with the lean AFR because the engine has to be really hot to start doing it. I suppose another trip to the dragstrip with a fuel pressure gauge hooked up. The idle surging problem is much easier to get, just drive it to dinner with some thrashing to heat things up... wait one hour and start it back up for a surge fest. The two problems are definitely tied together.

 

Starting to wonder about something... I know the fuel is constantly circulating through the rails and back into the tank. I'm wondering if the excessive underhood heat could be boiling the E10 in the rails once the whole tank of fuel gets warmed up enough? I've been reading the E10's boiling point is lower than straight gasoline. Just one thought of many on this issue.

 

From memory, the MS uses the classic speed density fuel equation which depends on IAT. Once your IAT sensor heat soaks it is going to pull fuel because the IAT is going to read hot which requires less fuel. So idling for long times will lean it out. Letting it sit and cool will richen it. Maybe MS does a coolant and IAT blend like some of the GM stuff does.

 

Right, it does have a built in MAT vs fuel adder formula with a minimum setting of 50% influence.. but I've eliminated that as the source of the problem by locking the IAT and MAT to high temps and the problem didn't show up at all when the engine was still in a low-normal operating temp.

 

It may be time to rebuild. I'm having a misfire that initially seemed like heat damaged plug wires. Two of them were. I replaced them but the misfire remains. I think most likely an oil fouled spark plug (valve stem seals are shot). It's also been making that 'weird' tapping sound for a couple of months. I decided I'm going to go through the engine before I start on the paint project.

This brings on the next dilemma... what parts to get and where from. It seems many common name brands are manufacturing everything in China. I'd like to get US made parts. I really like what I've read about Howards cranks (and HRC products in general). A little pricey compared to Eagle and the likes, but I keep reading about quality control problems on the cheaper stuff.

Also I've got to figure out where I can get everything balanced correctly. I have a certain FORD shop in mind.. I just gotta talk him into setting it up to hold a SBC crank

 

JMO on this, GM 1053 forged crank, decent H-beams (Scats are supposedly better than Eagle in this category if you go cheap, if you don't there are several other makers available) and pistons depending on budget. At least Speed Pros if not some JEs.

The tear down should be interesting. What's the plan for a cam heads and intake? Just stockers? I think that's where things could get really interesting.

 

i'm curious where you are running your timing at ?

 

Freaky - At 13 psi it goes from around 13 degrees @ 3100 to around 19 degrees @ 5200.. I'm not 100% sure where I left off at because it's been about a month ago since I went into the tune.

Draconic - The plan is to stay completely stock on the intake parts, although I did some minor porting to the plenum right behind the throttle body (removed the 'fingers' behind the TB). Heads are definitely going to get changed, it's mainly a question of iron vs aluminum at this point. Vortec heads are a possibility which of course includes an intake lower upgrade. Not a bad trade-off and I still retain a stock upper. Aluminum heads would be nice though to offset the weight I've added with the turbo component. Mainly I want heads that will improve exhaust flow a bit. My hope is to build an engine that makes 300 crank hp without the boost. Then it should be "easy" to make 500 with a turbo. All this with a goal to stay close to 20 mpg.

 

the vortecs would be a good choice. with a mild cam, the vortec headed motor will nearly run where you're already at, add a turbo and you could have quite the sleeper!


still rocking that ebay t70?

 

Yep it looks like the Ebay turbo just might outlast the engine! I'm going to take some plugs out and maybe I'll get lucky and find it on the driver side. I'm just not real excited about removing the turbo components to replace one of those plugs, just to put it all back together and deal with it again later, but it would theoretically go several months before it fouls again - if that's even the problem. But if it does buy me a month or two I should have time to get the new engine together. Would like to have it in by March at least.

I'm considering the following parts for my bottom end, anyone have any opinions on the quality of this stuff. I believe most of it is forged in China these days though:

http://www.summitracing.com/parts/SCA-1-41643BIE - not getting it from Summit.. would be getting a better deal through one of my speedshop customers. Has Scat gone the way of Eagle and started making problem parts or still quality stuff?

 

i've heard much better things about SCAT than Eagle


SCAT is cast offshore, finished and checked out here in the states.



another one to look into is PBM

 

I just got the Eagle kit from summit and my mechanic said the parts were dead on. Guess its a hit and miss as i herd good things and bad things from both brands.

Awsome car