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LTX and LSXPutting LT1s, LS1s, and their variants into Third Gens is becoming more popular. This board is for those who are doing and have done the swaps so they can discuss all of their technical aspects including repairs, swap info, and performance upgrades.
I have been watchin your progress on youtube. good stuff. I was curious to ask, with the steep 1st gear ratio in that transmission, what rear gear ratio do you think you will go with ?
I have been watchin your progress on youtube. good stuff. I was curious to ask, with the steep 1st gear ratio in that transmission, what rear gear ratio do you think you will go with ?
I think it has 2.73’s in it now but I’d like to swap some 3.42’s from a 4th gen.
So I’m working with Psiconversion for the wiring. They gave me a hell of a discount and I first ran their harness years ago when I ls swapped my Camaro. I love when companies you have experience with want to help out with a build. Koni did the same thing and sent me a set of shocks, as well Scott over at Bigbrakeupgrade sending me some conversion parts not too long ago. I was seriously considering a Holley system for this car too, but honestly its just so damn expensive! Their gen v terminator kit would have ran around 2200+, and a lot of the features would go unused. The biggest thing I hate about the terminator x in my Camaro is the lack of outputs. They only give you 4 inputs and 4 outputs. After wiring up the fans, a/c clutch, speedometer, and a shift light, you’re left with nothing.. The dominator comes with 20+ in’s and outs, but they don’t offer it for the gen V, and if they did it would probably be around 4k..
Anyway I sent the ecu and tcu out to psi today so they can flash a base tune as well as see if the 2011 tcu is going to communicate with the 2016 ecu. If it doesn’t Bobby at psi said they’ll swap the ecu with another unit that will work. In other news my paint came in today so next thing after the Holidays is to get the bay cleaned up and painted.
I think it has 2.73’s in it now but I’d like to swap some 3.42’s from a 4th gen.
I would advice that you try the 2.73 first. I started with 2.73's in a 4th gen 10 bolt and a torsen limited slip. When I switched to the 8.8 I did a 3.31 again with a torsen. With the 6L80's 4 to 1 low gear I think I would have liked about a 3.08 gear better. I think you will be surprised by how well the 2.73 gear works , especially if you use a mild stall converter. I went with a Circle D 24-2600 stall with lock up , feels stock till you get on it.
I would advice that you try the 2.73 first. I started with 2.73's in a 4th gen 10 bolt and a torsen limited slip. When I switched to the 8.8 I did a 3.31 again with a torsen. With the 6L80's 4 to 1 low gear I think I would have liked about a 3.08 gear better. I think you will be surprised by how well the 2.73 gear works , especially if you use a mild stall converter. I went with a Circle D 24-2600 stall with lock up , feels stock till you get on it.
Thanks for the tip. And I imagine 2.73’s would keep the rear alive a bit longer as well. For that converter do you have a stock cam? I couldn’t be more lost when it comes to picking out a converter. I need one for sure being the trans is toast.
My current engine is a stock Ls3 crate motor. The Circle D converter I have is the 278 mm . It is $599 or $699 if you add the billet front plate, I did not. It is available in two different stalls ,I chose the milder stall. My understanding is that it is a reworked GM converter to keep the cost down, with an improved lock-up clutch and bearing. If you plan on boost or NOS you may need to spend more.
The project is looking awesome! Great job so far!!!
I am absolutely loving the photos and YouTube videos of all the amazing work that you are putting into this car!
I was sad to see that the cylinder heads/ valves had all that oil/ carbon build-up... I tried to warn you and I really feel badly for you.
From my time spent as a GM engineer, I saw a ton of this on DI engines (I4s, V6s, and V8s). Sorry man.
I am going to give you another warning about that 6L80E transmission... They do not do well past 100,000 miles.
We (GM) kinda developed the new service/ maintenance schedule, so that the vehicles would just make the power-train warranty period (of 100,000 miles) and crap out... so customers would by a new vehicle.
This is why in most states, the service manual says that the transmission fluid (and other fluids) are a life-time fluid.
At the minimum, replace the pump and the valve-body... the valves in the pump and valve-body are very bad about wearing out at your mileage.
Obviously there are clutch packs that have burnt-up (most likely due to pump wear and AFL/ valve-body wear).
But I would have it rebuilt if you can afford it... or go to a 4L60E (or even better a 4L80E).
Good luck and have fun!
Last edited by vorteciroc; 12-31-2020 at 08:16 PM.
The project is looking awesome! Great job so far!!!
I was sad to see the cylinder heads/ vales had all that oil/ carbon build-up... I tried to warn you.
From my time spent as a GM engineer, I saw a ton of this on DI engines (I4s, V6s, and V8s). Sorry man.
I am going to give you another warning about that 6L80E transmission... They do not do well past 100,000 miles.
At the minimum, replace the pump and the valve-body... the valves in the pump and valve-body are very bad about wearing out at your mileage.
I would also have it rebuilt if you can afford it.
Good luck and have fun!
Does running cheap gas exacerbate the problem? Meaning, if you run a higher quality fuel with detergents do you see the same buildup? I'm hoping I dont have these problems with the L83 in my suburban. Bought new with 70k now.
Does running cheap gas exacerbate the problem? Meaning, if you run a higher quality fuel with detergents do you see the same buildup? I'm hoping I dont have these problems with the L83 in my suburban. Bought new with 70k now.
The premium (higher Octane) fuels help a little... just not very much unfortunately.
We (GM) together with a few different automotive chemical/ service companies (such as BG Products) decided on an "engine intake tract cleaning service" to treat this, when not too severe...
The chemical cleaning agent is added to a cylinder (shown in the photo), shop air is attached to the cylinder, and the chemical is sprayed via a large nozzle into the throttle-body (as in the photo).
This is performed for 5 to 10 minutes to clean the intake manifold, cylinder head intake runners and valves... sometimes 2, 3, or more times until clean.
The engine oil and filter are changed after this.
On heavy build-up engines...
The intake manifold is removed, the rocker-arms are all loosened (to close the valves) ,and the chemical is pored into each intake runner (to sit on top of the valves) over night.
The next day, the exhaust/ catalytic converters are lowered down (to have an open exhaust system) ,the rocker-arms and intake manifold are re-installed...
And the engine has the chemical sprayed through the throttle-body (just like I first mentioned).
If you have a flex-fuel vehicle...
Periodically filling up with E85 will clean-up a good amount of build-up, and also work as a preventative measure/ service.
Please see the link below containing the GM service bulletin that I wrote on this subject: LINK
Last edited by vorteciroc; 12-31-2020 at 08:09 PM.
I am going to give you another warning about that 6L80E transmission... They do not do well past 100,000 miles.
We (GM) kinda developed the new service/ maintenance schedule, so that the vehicles would just make the power-train warranty period (of 100,000 miles) and crap out... so customers would by a new vehicle.
This is why in most states, the service manual says that the transmission fluid (and other fluids) are a life-time fluid.
Is that pretty much true of any "filled for life" transmission, like the 6R80 in my 2012 Ford F150?
Is that pretty much true of any "filled for life" transmission, like the 6R80 in my 2012 Ford F150?
I can not say...
I am only in-depth familiar (hands on) with the GM variants of the ZF 6HP26 transmission.
The ZF and Ford variants are of the original ZF design... GM made significant changes to all of their variant transmissions.
There are significant changes to the Pump, valve-Body, and some of the Gear-Train, for all GM Units regardless of Model-Number.
The wear and tear that I have seen with the GM "6L" units has been 100% inline with the 100,000 mile GM planed obsolescence program that is currently in place.
The GM 8L series did not even make it to 100,000 miles and is under "Class Action Law Suit" from multiple agencies.
The GM 10L series is part of the "Life Time Fluid" plan, but I do not know yet; what will come of this program... I am hoping it is far superior to the 6L program.
This is bothersome if true. Seems more like 80's GM of past. I've had GM trucks my whole life and they all have treated me amazingly (150k to 200k miles). I hope the 6l doesnt go out on my suburban. I've already changed the fluid (manual said @50k miles for extreme). Does GM really feel their market base can afford a 50k to 80k truck/SUV every few years? 100k miles is nothing anymore for cars.
This is bothersome if true. Seems more like 80's GM of past. I've had GM trucks my whole life and they all have treated me amazingly (150k to 200k miles). I hope the 6l doesnt go out on my suburban. I've already changed the fluid (manual said @50k miles for extreme). Does GM really feel their market base can afford a 50k to 80k truck/SUV every few years? 100k miles is nothing anymore for cars.
Generally speaking... the better you take care of your vehicle, the better your vehicle will take care of you.
The unfortunate truth of the matter, is that a significant amount of people do not properly maintain their vehicles (especially with leased vehicles) and even more people would rather have a vehicle with fewer maintenance requirements.
Well, GM jumped on the band-wagon and gave the people what they want!
The result being that vehicles do not last as long... and this so happens to make it so that people will have to purchase (or more likely lease) vehicles more often.
The majority of the GM vehicles purchased or leased today are $50,000+ crossover vehicles and SUVs.
GM decided that if people do not wish to maintain their vehicles... then GM might as well profit from that, and have a higher vehicle turn-over.
This is a "movement" that has been coming for a long, long time...
Fewer and fewer components/ parts are rebuildable/ repairable and vehicles are becoming more and more disposable.
Eventually service and repair will be reduced down to almost nothing, and vehicle sales and leases with grow significantly.
50 years from now: O, you need your first oil change? ... Well, we might as well get you into a new vehicle!
Generally speaking... the better you take care of your vehicle, the better your vehicle will take care of you.
The unfortunate truth of the matter, is that a significant amount of people do not properly maintain their vehicles (especially with leased vehicles) and even more people would rather have a vehicle with fewer maintenance requirements.
Well, GM jumped on the band-wagon and gave the people what they want!
The result being that vehicles do not last as long... and this so happens to make it so that people will have to purchase (or more likely lease) vehicles more often.
The majority of the GM vehicles purchased or leased today are $50,000+ crossover vehicles and SUVs.
GM decided that if people do not wish to maintain their vehicles... then GM might as well profit from that, and have a higher vehicle turn-over.
This is a "movement" that has been coming for a long, long time...
Fewer and fewer components/ parts are rebuildable/ repairable and vehicles are becoming more and more disposable.
Eventually service and repair will be reduced down to almost nothing, and vehicle sales and leases with grow significantly.
50 years from now: O, you need your first oil change? ... Well, we might as well get you into a new vehicle!
You are so correct. Its a shame really. I've leased but always took care of the vehicle in case I bought it (which I did with this suburban). Hope it takes me to 200k.
The carbon build up on the intake valves on DI vehicles is partially due to a lack of valve washing that occurs in MPFI vehicles. This can be somewhat alleviated by using a catch can on the PCV system (this is where the carbon comes from). I use TopTier fuel (Shell in Canada) to aid as well in my car (twin turbo v6 with DI).
Unfortunately, use of a catch-can has not really made a significant change...
We (GM) have been experimenting with solutions/ improvements to this condition for many years now.
The C8 Corvette engine has the solution that will end-up in the other GM engines over time.
Port EFI injectors were added to the intake manifold of this Mechanical/ Direct-Injection engine to have a "wash-cycle" so to speak.
The C8 engine did very well in short term testing (up to about 30,000 miles).
The C8s on the road now will show us how much the improvement will add-up to.
Generally speaking... the better you take care of your vehicle, the better your vehicle will take care of you.
...people don't maintain cars, so now they are disposable.
Shortened that for you . Just out of curiosity, My wife drives our G8 GT (L76/ 6L80) harder than I do (though neither of us abuse it, nothing like what I used to do as a teenager/young 20s) and we're getting close to 195k miles, we've had it since 2013 and 85k miles. I know we've never done anything to the trans, though the engine was out under warranty around 30-35k. I vaguely remember a small leak when we bought it that was taken care of before delivery, might have been the trans.
Would you recommend doing anything to the trans? Or ride it out for however long it goes?
Shortened that for you . Just out of curiosity, My wife drives our G8 GT (L76/ 6L80) harder than I do (though neither of us abuse it, nothing like what I used to do as a teenager/young 20s) and we're getting close to 195k miles, we've had it since 2013 and 85k miles. I know we've never done anything to the trans, though the engine was out under warranty around 30-35k. I vaguely remember a small leak when we bought it that was taken care of before delivery, might have been the trans.
Would you recommend doing anything to the trans? Or ride it out for however long it goes?
I’m almost ready to start working on this thing again. I went on a tangent and did some serious organizing in my shop space. I got tired of tripping over misplaced crap and extra parts. I should have everything wrapped up this weekend then it’s back to the trans am. I went a little overboard with a whole new paint job, but hey I figured its for the “set”😂
Finally back at it, started tearing the engine bay down to prep/paint. Battery tray was looking pretty crusty so I decided to swap it out. Snow removal slowed me down this week and I only have tomorrow to get some work done until next week. Hoping to at least have the battery tray welded up and the rusty spots sanded down and por 15’d.
I also pulled the dash so I can swap out the water logged firewall insulation. I’m gonna throw a heater core in while I’m at it and I need to fix the munched parts of the dash harness. Yea I finally figured out where the mice got their nest materials from..
Yikes! I'm glad I've never seen evidence of mice in mine... That must be a bear to clean.
Out of curiosity, how tough is it to remove the dash? My heater core has been full of coolant and sitting for ~10 years so it's probably worth changing. I've also got all the wires from pre-LS engine just hanging out waiting to be cleaned up. Or should I go and look for a new video on dash removal on your channel?
Its nice to see all the work that has progress on your project. I see a few things that can cause more problems. Using the Holley LT Accessory Kit will solve the lower AC problem and add power steering. Using this kit will allow the use of Dirty Dingo Adjustable mounts. I have a lot of clearance near the firewall with these mounts. I am running the TR6060 trans but your auto seems to be a tight fit. What are you going to use for the fuel system? The stock PWM system does work pretty good. Maybe ask PSI about adding that to your harness. If you have any questions, feel free to ask. I did a ton of trial and error so I can help you so you don't waste a lot to time. Holley LT Accessory Kit
Its nice to see all the work that has progress on your project. I see a few things that can cause more problems. Using the Holley LT Accessory Kit will solve the lower AC problem and add power steering. Using this kit will allow the use of Dirty Dingo Adjustable mounts. I have a lot of clearance near the firewall with these mounts. I am running the TR6060 trans but your auto seems to be a tight fit. What are you going to use for the fuel system? The stock PWM system does work pretty good. Maybe ask PSI about adding that to your harness. If you have any questions, feel free to ask. I did a ton of trial and error so I can help you so you don't waste a lot to time. Holley LT Accessory Kit
Gen V LT1 in 88 IROC
The A/C has a lot of room now so I should be good there. The bell-housing comes pretty far into the bay which is good because it allows for it to tuck up into the tunnel more. For the power steering I’m planning on using a ford/volvo electric unit that can be mounted somewhere in front by the radiator. The main reason I’m staying away from aftermarket accessories right now is for cost. I’m really trying to get away with the truck stuff, and so far it looks really promising. Once boost comes into the picture I’ll probably be going aftermarket to accommodate the turbo/s.. Being this is all being done on Youtube I want to do everything pretty budget being the motor comes with all these accessories anyway. Hell if I had the time and patience I would re-pin the truck harness and use that as well.
I also spoke with the guys at psi and they said I can run a regular fuel pump with around 70ish base pressure. I forgot the exact number, maybe more like 74-78? Once again keeping costs down being I have a lot of fuel pumps collecting dust. Also if I haven’t mentioned it already, for the sake of YouTube I’m doing this build in stages. So I’ll get it up and running with some passes just on the n/a 5.3/6l80e and a tune. I also took some dragy passes on the old smog 350 setup, so I can’t wait to compare this stock Yukon power plant to the 8.8 0-60 the old stuff gave me. After that its going to be stage 2 time with heads and a cam, then 3 will be boost time aiming for 1000ish hp. Its going to be absolutely stupid and I’m excited as hell. Driving around in a stock riding/looking 3rd gen with that power is completely unnecessary..
Oh and subframe connectors will make their way in the car before the first stage of the setup hits the ground.
This snow every few days has been killing me on progress! Whenever I work on the trans am I need to pull the Camaro out for space, so whenever it snows that means I need to spend the morning removing it from in front of the garage. Plus I started messing around with stocks so I kill a few hours each morning making mostly stupid trades..
Anyway I got the battery tray welded in and wire wheel’d any flaking spots around the bay. I’ll be back at it all day Monday being I’m off from the day job. I hope to have the remaining rust por 15’d with the bay cleaned and ready for scuffing and primer.
I just watched a lot of your youtube videos on this project plus the water pump video. They all are produced pretty good. I like the one where you used a grinder on the transmission to adjust the engine angle. I agree that your fuel line should be moved.. My engine angle is over 5 degrees. I get driveline vibration which I think is due to pinion angle or maybe a worn rear. I installed a QA1 adjustable torque arm to adjust the angle but it still vibrates. Now I'm thinking of pulling the engine again and see if I can do some grinding like you did. I did my share of tunnel pounding but that just didn't do much. I dread having to cut the tunnel.
I was wondering how you will attach the throttle body with that belt in the way. If you look at the holley LT accessory kit, you will notice they use what looks like the truck water pump, like you have in your Tahoe. That may work for you.
I agree with your weather comment. I have a heated garage but who wants to waste money keeping it heated all the time. First I need to move my truck out, then turn on the heater, wait a few hours, then back to work. Biggest problem is doing everything for everyone really cuts into the time I should be devoting to my project. Its taking way longer then I like.
I just watched a lot of your youtube videos on this project plus the water pump video. They all are produced pretty good. I like the one where you used a grinder on the transmission to adjust the engine angle. I agree that your fuel line should be moved.. My engine angle is over 5 degrees. I get driveline vibration which I think is due to pinion angle or maybe a worn rear. I installed a QA1 adjustable torque arm to adjust the angle but it still vibrates. Now I'm thinking of pulling the engine again and see if I can do some grinding like you did. I did my share of tunnel pounding but that just didn't do much. I dread having to cut the tunnel.
I was wondering how you will attach the throttle body with that belt in the way. If you look at the holley LT accessory kit, you will notice they use what looks like the truck water pump, like you have in your Tahoe. That may work for you.
I agree with your weather comment. I have a heated garage but who wants to waste money keeping it heated all the time. First I need to move my truck out, then turn on the heater, wait a few hours, then back to work. Biggest problem is doing everything for everyone really cuts into the time I should be devoting to my project. Its taking way longer then I like.
Thanks for the positive feedback on my videos. The trans am ones take some time but they are my favorite to make. Oh yea and even though I never did any work on my projects during the winter BEFORE getting an indoor space, I’m making pretty much the same progress especially waiting for the place to warm up like you mentioned😂
For the trans tunnel I didn’t even hammer very much and it still made a pretty good difference. Once that high spot on the spine of the trans is smoothed down, most of the hammering is done near the tailshaft. Once I’m in the process of getting the crossmember set up I’m hoping to massage a little more of the tunnel and get it up a bit higher. The closest spot right now is at the fuel lines where they are keeping it from going up any more.
Engine bay painting is done and the video hit youtube today. It took me a whole month to get this wrapped up but I’m really happy with the results. Hopefully the snow backs off so I can rip through the interior prep a little faster. I ended up painting the cowl while I was in there and re-finished the k member with some por 15 and a top coat of satin vht. Next up is heater core replacement, firewall insulation, rust repairs on the floor boards, and sound deadening the entire floor/most of the interior. I’ll keep the updates coming👍
Well I kept peeling back the onion and the interior is no more. I pulled the heater core and found it stuffed with rat **** along with another nest. Also found a dead one on top of it. I have some rust that needs to be fixed, but I’m not sure how I want to go about it. The driver side has some random little holes but overall is solid. Theres also a significant hole right behind the heater box where the floor seam meets the firewall. That should be a simple cut and fix, I just don’t know how much of the driver side I want to cut out and replace. In addition to all that I managed to get some more engine bay stuff painted, and I might just powder coat the column brackets and brake pedal assembly being they’re small enough to easily do. Lastly I got the fuel door cut and the Detroit Speed unit welded in.
just to clarify, that is the DSE fuel door setup? I might eventually want to go that route. I am surprised they didn't make it an inch bigger on the sides so it had more material at the edge instead of it meeting the Sheetmetal right after the oem stamp/roll/curve. interesting.
engine bay looks great. brings me back to last January when I went crazy inside mine doing all that stuff
ah! gotcha. thanks fellas.
That makes much more sense!
This might be a project I do while the roll-bar is welded in because the fuel tank will be removed for that project.
Good to know. thanks
Next video finally went up. Did some rust repair on the floors, finished up some stuff in the engine bay, laid down some sound deadening and new firewall insulation. Next up is wiring.
Looks great. I like how the hushmat squares are smaller. The Eastwood product I am using is large and needs to be cut down. What are the black sound deadening squares? Are those a hushmat product?
Yuk!!! Man I so don't miss living up north but I guess for 30+ years this one isn't that bad, but still Yuk
I think the deadening is excessive? I have never added any in any of my cars but does it really make it tomb like?
I think the deadening is excessive? I have never added any in any of my cars but does it really make it tomb like?
100% coverage on VIBRATION dampening, like this, is a waste of product and gains no more benefit over a 25-40% coverage area. If you really want sound deadening, you add mass, like the factory mass backed carpet. I did 25-40% vibration damper, 100% 1/8" closed cell foam over that, then 100% mass loaded vinyl, then the factory mass backed carpet. I didn't even finish and my car rivals new car sound levels in the interior
100% coverage on VIBRATION dampening, like this, is a waste of product and gains no more benefit over a 25-40% coverage area. If you really want sound deadening, you add mass, like the factory mass backed carpet. I did 25-40% vibration damper, 100% 1/8" closed cell foam over that, then 100% mass loaded vinyl, then the factory mass backed carpet. I didn't even finish and my car rivals new car sound levels in the interior
Yea I read about the 25% rule. This stuff was really cheap and being I already had 3 boxes, I just decided to cover everything. Being the floor was seam sealed and mismatched I wanted a clean surface to secure my wiring too, plus I figured it may provide an extra barrier in case the t tops leaked again. I have oem carpet going in with the heavy backing so I didn’t go as crazy with the foam sheets.
Hey Matt, great build. Wondering if you ever came up with a solution for the exhaust. I'm in the planning stages of an L83/6 speed swap and that's about the only piece I haven't figured out yet. Fall back plan is to just fab up exhaust to the stock manifolds, but kind of hoping someone out there has a header solution that works.
Actually, I did a 6L80 in a 91 Camaro vert. in 2012-13 . The engine was a 5.3 LS and later an LS3 . I put about 40,000 miles on it before I sold it last year.
12-21-2020, 08:22 PM
and I really feel badly for you.
. Just out of curiosity, My wife drives our G8 GT (L76/ 6L80) harder than I do (though neither of us abuse it, nothing like what I used to do as a teenager/young 20s) and we're getting close to 195k miles, we've had it since 2013 and 85k miles. I know we've never done anything to the trans, though the engine was out under warranty around 30-35k. I vaguely remember a small leak when we bought it that was taken care of before delivery, might have been the trans.
