My LS-Coupe Turbo Build

[racrguy]

I'm going to, I'm sure itis not legal.

The exhaust exits outside the passenger cabin, and the turbocharger counts as a muffler. It's a '79 with the aero front end put on it right? No worries about emissions testing as it's exempt.

[dville_gt]

The exhaust exits outside the passenger cabin, and the turbocharger counts as a muffler. It's a '79 with the aero front end put on it right? No worries about emissions testing as it's exempt.

Ya, it's a 1979 w/the updated interior/exterior. Just not sure if there is a rule about exhaust exiting before the front axle! lol!

[racrguy]

Ya, it's a 1979 w/the updated interior/exterior. Just not sure if there is a rule about exhaust exiting before the front axle! lol!

I'm pretty sure as long as it exits outside the passenger compartment all is good. You may want to do some digging on that one. It's going to be loud as shit, but it'll be legal. lol

[2165 Turbo Rail]

I always thought it was ok if behind the rear axle

[2165 Turbo Rail]

Fails if: The tailpipe fails to discharge exhaust from the rear or sides or top of the passenger compartment of the vehicle.

So seems like it "should" be ok

J at the very bottom.
http://www.txdps.state.tx.us/vi/insp...Exhaust+System.

[dville_gt]

Fails if: The tailpipe fails to discharge exhaust from the rear or sides or top of the passenger compartment of the vehicle.

So seems like it "should" be ok

J at the very bottom.
http://www.txdps.state.tx.us/vi/insp...Exhaust+System.

LOL! Definitely a grey area I'd say. "Side of the passenger compartment" might not exactly define what mine does!

[racrguy]

LOL! Definitely a grey area I'd say. "Side of the passenger compartment" might not exactly define what mine does!

Worst case scenario, take it to an inspection shop with that printout and ask them if it'll pass. If there's a dB requirement you may be screwed, but fuck it, I bet it's fun.

[80coupe]

on my 80 i had dumps he wouldn't pass it he said as long it was out from under the car he would pass it and didn't care if i had it coming out in front of the front wheels as long as it wasn't dumped.

[dville_gt]

Got to drive it for the first time today. Didn't get into it much (only about 50% throttle), just really checking for any problems/leaks/etc. Everything was good (except my meth tank which was leaking like crazy). Turbo sounds NUTS, videos don't really do it any justice. Granted today is not hot, but engine ran cool (right at 196 which is where the thermo opens), and IAT's stayed right at 90*. I'm pretty stoked, even though I didn't really get much boost (only 2-3lbs per my log @ 65% throttle and 3800rpm), it felt like it was about to get insane!

[Buick355]

Damn man, you really whipped that out. What's left to do before you can start railing on it?

[dville_gt]

Damn man, you really whipped that out. What's left to do before you can start railing on it?

I just wish the car wasn't out in Weatherford, I've only gotten to work on it like once or twice a week.

[TTls1coupe]

We might have to line up our stock to stock turbo ls1 cars at the next cruise. How much power you trying to make?

[Z06killinsbf]

Bad ass dude!! I think it depends on where you get it inspected. My truck had a dump before the axle and the guys passed it.

[dville_gt]

Little update:

Good news and bad news.

Good news it I made the drive from Weatherford to Arington last night without a single hiccup.

Bad news is that I am retarded. The car has a pretty severe stumble/breakup when it goes into boost. Contacted Brooks and he pointed at my plug choice. Switched them out, and while better, still not good. My logs showed nothing out of the norm, no knock, all the sensors were reading good, afr at 10.93:1 (while rich, provided some room for error). I was stumped. Then I realized that the afr seemed to go straight to 10.93:1 and stay there as soon as I went into power enrichment. Like flat lined at 10.93:1.

Turns out that I copied my formula in HP Tuners over wrong. I use a spreadsheet to come up with a ground offset formula since the HPTuners module and the wideband have a slight ground offset. Well the formula ended up being Volts/.625+10.093 (volts being the 0-5 volt reference / .625 to get the value of each volt) + 10 (the value of 0 volts) + .093 (the ground offset).

Well, somehow I copied that over as volts/.625+10.93. So the lowest value it could read is 10.93 vs 10.00, so actually 10.93 is 10.00 (and every other value I was using was .93 afr points off). So when I saw it go to 10.93:1 during power enrichment it was actually bottoming out somewhere below 10:1. I am not turbo tuning expert, but I assume sub 10:1 afr's could lead to some stuttering/breaking up.

I also feel bad driving it all the way home from Weatherford at what I thought was ~13.5:1 (which was actually closer to 12.5:1).

Anyway, going to make those changes to HP tuners and lean my VE table way out tonight and see how she reacts. I hope I didn't foul out those new plugs in the process of figuring this out!

Oh well, guess it's better to have been a point or more rich then a point or more lean!

[dblack1]

Oh well, guess it's better to have been a point or more rich then a point or more lean!

Damn straight. I'd rather replace plugs than pistons/head gaskets.