I would just continue this thread. You started it, so nothing is being hijacked.
As far as VVT, call Cam Motion and/or Texas Speed. They can fill in any blanks you may have on whether or not it would suit your build.

 

Pat G spec'd a VVT cam for my 5.3 gen 4. While my truck is a Tahoe and twice as heavy as your TR7, It may give you some idea of what your looking for. I was going for daily driven with a little gain. 212/218. 566/566. 115+6 VVT. The phase limiter is also necessary to keep things from meeting unexpectedly. My heads had .020 shaved mild hand finished bowls and ports. PAC1218 springs and still no PTV issues. Hope this helps. It was a peppy little setup for a 5700lbs vehicle. Then the old HP bug hit and it's down the rabbit hole I went.

 

Thanks to both of you.

The rabbit hole is what I'm trying to avoid. LoL.

I keep searching the forums here and I have yet to find any definitive information on making VVT work with a manual transmission. The problem seems to be what computer to use. Most of the threads die right before anyone comes to a conclusion. The closest one I found was a guy that was swapping a 6.0 from a Cadillac CTS-V that came with a 6 speed but he was either having issues with his computer (E67 I think but I'm only trying to repeat what I read. I have no clue for sure) or something else. What I have found so far isn't promising. This thread leads me to believe it is possible.....

https://ls1tech.com/forums/manual-tr...h-options.html

This thread didn't seem to come to any answers either

https://ls1tech.com/forums/pcm-diagn...-solution.html

This one didn't get any response and was really disheartening

https://ls1tech.com/forums/pcm-diagn...t-lh9-e67.html

This is the one with the Cadillac 6.0, but it didn't get resolved either

https://ls1tech.com/forums/pcm-diagn...-spd-tune.html

I know some of them are old threads, but it isn't looking good unless I'm searching in the wrong areas.

Any ideas?

Thanks

 

Apparently they are doing this in Jeeps with the E38ecm and retaining the VVT. MOTECH has a diy kit for Jeeps. I know yours is not a Jeep but it may lead you to the pieces you need to make your setup work. Found this info on EFILive forum.

https://forum.efilive.com/archive/in...p/t-24358.html

 

I ran VVT with a t56 in my Chevelle. Worked great. Mast VVT camshaft with Mast Electronics. Mast at one time was the leader in aftermarket VVT for LS stuff, but when folks found out that it didn’t work well with GM VVT controls due to not being able to go into negative camshaft control as far as Mast had designed it to, they gave up.
I still have the engine in my shop. It’s an LS2 with an LS3 top end (think LY6 with aluminum block) and I have that t56 as well. It’s supposedly sold but I haven’t seen any money yet...
For the record, I am a huge VVT fan. The tech is legit and the application really does improve the powerband and make the driving experience better.

 

Thanks Che70velle.

So it seems it was a possibility at one time, but Mast has given up on the project? It's too bad, but I guess with the death of the manual transmission in the US there wouldn't be much market for it anymore. From a new guy looking from the outside in, to me it is a shame if Mast's programs demise was from people chasing peak numbers and "bragging rights" and not seeing the big gains available across the board. I know it seems bass acwards for a mild build when the hp potential of the LS platform is so great. But, the market drives what sells and what doesn't. I'm not seeing anything on the Mast site for VVT other than cams so I am assuming the idea of a Gen IV 5.3 with VVT and a manual transmission is pretty much a unicorn (unless it can somehow be ADDED to a Gen III L33) and something I shouldn't be chasing anymore.

The idea of so much better performance below peak hp / tq was something I was really hoping to get to work. Not to mention the mpg gain. Best of both worlds. To move up in displacement to something that may have come with a 6-speed and VVT puts me into a much higher stock hp range and "upgrading" that cam would be pointless and make the little car nearly undriveable.

Unless someone has any new ideas or information in the next few days I'll probably let this idea die and go back to designing an L33 to be as efficient as possible and try and get as close to 325+ rwhp as I can. I may try contacting Mast and see what they think, but I'm afraid I already know the answer to that question.

Thanks again for the leaning

 

G Atsma.....I'll try contacting Cam Motion and Texas Speed also, but I feel the answer might be the same as I get from Mast. I guess there's always a little hope until there isn't.

 

Mast had only one mission with their VVT development. TSP and Cam Motion are aiming more towards the everyday user. Give them a call and hopefully you will be pleasantly surprised. In the mean time go online and checkout what they have.

 

Good friend had a TR8 back in the day. Very cool car. Essentially a 215 Buick V8. I had several 215 Vegas back then.

Anyway, you are doing an NA build. Alum block smart in that tiny car.

L33 will be perfect. The later ones can be converted to 24x all the other stuff deleted.
Shoot, an LS1 would be dandy as well.

Just keep it simple.

There was also a LM4, alum version of the LM7 5.3.

You do not need the benefits of the later blocks!

Mast EFI software? Please. Who uses that? I tuned a car with it. There is a reason Holley rules.

Stock 24x ecu is very capable.

 

So after a call to Cam Motion I am seriously considering the L33 again, but it did bring up another question. (Man OCD sucks)

Even with the advantages of keeping the VVT and doing a mild VVT cam swap, is there any real advantage for my situation? What I mean is that if I am planning on cruising this car at something like 1800-1900 rpm down the highway is there any real advantage? Wouldn't the VVT advantage really take place at over something like 2300 rpm? In my case 2300 rpm would be around 80 mph in 6th (0.63). I can see where there may be some advantage to be realized in 1st-4th gear from light to light, but for the most part, my in-town driving won't be "spirited" by any means. Well....maybe once in a while. Or twice in a while. I would love to have the chance to take a "spirited" lap or two at Road America or VIR, but in reality i wouldn't care about VVT at that point. And probably wouldn't happen anyhow.

I'll keep investigating and learning, but I think I'm beginning to see that the L33 may be the simplest route towards what I'm looking to do. Build something I want while learning all I can at the same time. Maybe the VVT thing is me standing at the edge of the rabbit hole looking in.

Thanks again for all the insight and keep it coming as you see fit. I am constantly learning from you all.

 

Me. Wish I had the Gen4 setup however. It’s easy to tune. I have a Holley setup in a truck also and it’s easy as well.

 

WARNING.......I have absolutely no tuning experience and this is probably a silly idea but here goes.

VVT, from what I understand works from a "physical" input. Meaning that the advance / retard happens because of a pressure (oil ?) change right? Not a solenoid or sensor "inputting" a signal into the ECU to cause the advance / retard event. If I have that wrong then this whole idea is already D.O.A.

So, if I have an LS based engine with VVT and delete it, what happens in the computer? It's looking for input that it isn't seeing anymore with the delete right? Are there some "parameters" that are essentially nulled out because the input doesn't exist anymore? Somehow the factory ECU has to be adjusted for the delete and the loss of signal. So, if VVT is usually used with automatics (6L80 ?) and then is deleted, those parameters would have to be adjusted or possibly nulled out right? So it makes me wonder, can you keep the VVT and adjust the ECU as though you deleted it? You would still see the advantages of the VVT advance / retard event because it's still happening physically, but the computer might not know it because you told it that it wasn't going to see any VVT input. And if this is true (which it probably isn't) then COULD you run a manual transmission behind an LS with VVT by doing what I described above?

I'm sure there are other signals the automatic sends to the ECU that it probably needs so it kind of makes this a moot point. But in the gas mileage game (which I play with my truck) we used to trick the computer by adding a resistor in series with the IAT sensor to make the ECU think the incoming air was 10° colder than it actually was. Sounds counter intuitive to make the air seem "denser" because the ECU would have to add more fuel to keep it at stoich. But the real advantage was it advanced the timing about 4° and gave a better combustion event. Dad told me that back in the day, you could just slightly rotate the distributor cap and advance the timing. Can't really do that with coil packs, but this worked. So, if you knew what the ECU was looking for voltage-wise couldn't you just jump a plug with a resistor to adjust for a specific value, and trick the ECU to think it's still an automatic and just run the manual behind it?

Or have I just fallen off the deep end and need to go see an LS therapist to get my head on straight again?

 

If you physically remove VVT, the ECM needs retuning to reflect that change.

 

Yessir, you have it wrong. There is a solenoid behind the front cover that receives signals from the ECM to direct more or less oil through the bolt in the center of the mechanism, based on engine load and where the cam sensor tells the ECM the camshaft actually is. The VVT setup is simple, yet its a very complicated and precise system.

 

Well I figured it was a crazy idea anyhow. But at least I learned something. It's becoming obvious to me that even to get the vvt/manual combination to work it's beyond my skill level at this point. (Can you say duuhhh?) I want to do as much of this build as I can myself and still ask for help when I need to.

​​​​​​That pretty much seals up the decision for me. L33 is my final answer. Thank you all for being my "phone a friend" with this question. Maybe someone will find this in the future in a search and add the magic formula and it will help someone else. Who knows?

I'll have fun building and learning about my choice. I think I recently saw an L33 long block online for under $1k. Half day drive to get it though. Someone suggested Yates in Davenport Iowa and I'll give them a call too. Much closer and maybe I can form a relationship with them for being my parts place.

Thanks again to everyone for their information and patience.


​​​​​

 

Check out car-part.com

 

I am also going with a L33 for my Porsche 944. From what research I have done it’s the best option since it has the better heads on it, I also have mild goals of 375-400 hp so I really don’t need big cubes. I ordered mine from lkqonline for about $1500 shipped. I’ll be following your build, good luck with it.

 

Hate to dredge up this old thread but I just want to check my mental math on this.

L33 is rated at 315 hp. I'm assuming that's at the flywheel. So figuring in the drive train losses and the manual transmission, that would be about 15% less at the wheels? Something around 270 rwhp? With a better intake (LS6 or Dorman LS2), freer flowing exhaust, mild cam upgrade to something that makes more power across the bulk of the power band, and a good professional tune, can I expect to get that to around 310-320 at the wheels? Or do I have it figured wrong?

Trying to finalize the engine plan and I am there unless I have messed up my off the cuff calculations.

Thanks again

 

Drivetrain loss is not a percentage. It's a fixed amount per component. All trannies and rear ends are different.

 

Depending on drivetrain I think 300-ish rwhp is a realistic goal for a cam plus bolt on 5.3