[wang970305]

Hi All,

I am looking to get a re-tune with GPI due to some hard downshift tuning issue experiencing. I have my current set-up in the signature. Is there anything else I could add on to benefit this re-tune? Not a big fan of the Heads&Cam.

Two things I am thinking are

1. TCM unlock
2. port out LT2 IM to true 95mm(I think MSD wont benefit too much since I am not camming the car)

Any other recommendations?

[FlukeSS]

Might want to read the A10 recall in the TSB section. Hard shifting is a symptom. And yes it will effect stock cars just as well as modified, rather TCM tuned or not. Not saying this is your issue but your car falls within the recall range as does mine. And you'll want to read the whole thread for all relevant details don't just skip past posts. GM is refusing to fix this issue, and in our case they already blamed my engine modifications for causing your issue just as well as mine.

https://www.camaro6.com/forums/showthread.php?t=632693

[wang970305]

Originally Posted by FlukeSS

Might want to read the A10 recall in the TSB section. Hard shifting is a symptom. And yes it will effect stock cars just as well as modified, rather TCM tuned or not. Not saying this is your issue but your car falls within the recall range as does mine. And you'll want to read the whole thread for all relevant details don't just skip past posts. GM is refusing to fix this issue, and in our case they already blamed my engine modifications for causing your issue just as well as mine.

https://www.camaro6.com/forums/showthread.php?t=632693

I thought it was just for the lock-up.

[FlukeSS]

Originally Posted by wang970305

I thought it was just for the lock-up.

Hard shifting is a symptom before it happens. Even if you modified anything otherwise, it can still happen.

If you want to know the mod I recommend first. Next Gen Drivetrain Valve Body upgrade kit for the A10. Knowing your car is going to be on the recall list along with mine. Which is to say 2020-2022 Camaro A10's. The upgrade will tell you if you only need the valve body upgrade or a new transmission.

The other reason I brought it up is we are both obviously modified and Chevy and GM are going to refuse to cover the recall in your case, as they already have in mine. Or you might get lucky and find a good Chevy dealer that will do the upgrade for you since GM says there's no fix for it. When there is.

All I'm saying is to keep it in mind. Even if you unlock the TCM and tune it, it will happen eventually. $1000-$1500 now for the valve body upgrade kit, or $3000-$6000 later when the trans blows up? At least check if your car is on the recall list. Then decide if you want to add more power knowing what can happen to the trans.

And to answer your question in #2: Porting the LT2 will yield gains, not porting it does nothing for the 95mm TB you have installed. (Creates a bottleneck so you are no different than if you were running the stock 87mm TB) MSD will yield better gains, especially if you use a 103mm TB instead of the 95. It also allows you to run higher rpm shift points on the top end. Right now my LT2 is ported to 95mm for the 95mm TB, and I run up to 7100 rpm before the car shifts. But the cam I have can handle upwards to 7600+ rpm as I found out when it hit the rev limiter during tuning. You can probably run upwards of 7500 rpm depending on your power band with the MSD and assuming the stock cam/crank can handle those RPM's.

[Gunkk]

+1 for the next gen upgrade/fix.

[FlukeSS]

Also for clarification I thought the GPI Ported LT2 is already ported for 95mm. So you may want to double check that.

I am not sure you need to port the LT2 again as you suggested in #2.

Yes they even have it as an option on their site:

[wang970305]

Originally Posted by FlukeSS

Also for clarification I thought the GPI Ported LT2 is already ported for 95mm. So you may want to double check that.

I am not sure you need to port the LT2 again as you suggested in #2.

Yes they even have it as an option on their site:

the one I had is the $300 option; they sort of cleaned up the snout, but did not match the 95mm opening

[FlukeSS]

Originally Posted by wang970305

the one I had is the $300 option; they sort of cleaned up the snout, but did not match the 95mm opening

Understood,

Then yes, that means you are basically running a stock 87mm TB because of the bottleneck.

You will see some gains if you port the snout to 95mm for an even match with the 95mm TB.

Your tune may need to be readjusted to account for that as well, as the intake air will increase in volume.

[wang970305]

I have been doing some research. One of my friends if selling his unported MSD. Should I swap out my ported LT2 for his MSD with the same LT5 TB?
I have not seen any posts about this comparison

[7speed]

Depends on if you get a good price on msd. Also if you decide to cam later might be time to switch up like I recently did.

[FlukeSS]

Originally Posted by wang970305

I have been doing some research. One of my friends if selling his unported MSD. Should I swap out my ported LT2 for his MSD with the same LT5 TB?
I have not seen any posts about this comparison

MSD's shine significantly more with a cam, but also a 103mm TB.

Its a noticeable difference between the LT2 and 95mm. And with a cam even more so.

You'll be able to run 7000+ rpms easy with an MSD 103, and a cam.

Issue with cam though is if you do a cam, its a good time to start strengthening the internals some, such as Drop in Rods and Pistons, Thrust bearing upgrade, dual valve springs among other things. Even an LT4 fuel system upgrade as well. And if A10 a Circle-D torque converter will help a lot on the low end launches.

But we are talking like 10-15k+ worth of work.

[wang970305]

Originally Posted by FlukeSS

MSD's shine significantly more with a cam, but also a 103mm TB.

Its a noticeable difference between the LT2 and 95mm. And with a cam even more so.

You'll be able to run 7000+ rpms easy with an MSD 103, and a cam.

Issue with cam though is if you do a cam, its a good time to start strengthening the internals some, such as Drop in Rods and Pistons, Thrust bearing upgrade, dual valve springs among other things. Even an LT4 fuel system upgrade as well. And if A10 a Circle-D torque converter will help a lot on the low end launches.

But we are talking like 10-15k+ worth of work.

Yeah, appreciate for the advices, I know Cam cost a lot of money just for labor, but didnt know other internal components as well. I dont think I would put that much strress for this camaro. I found a good deal for a MSD, just wasnt sure if theres any valvue of swapping my LT2 out for some improvement

[FlukeSS]

Originally Posted by wang970305

Yeah, appreciate for the advices, I know Cam cost a lot of money just for labor, but didnt know other internal components as well. I dont think I would put that much strress for this camaro. I found a good deal for a MSD, just wasnt sure if theres any valvue of swapping my LT2 out for some improvement

You may not notice much between the LT2 and 95mm, and an MSD with a 95mm. But you'll definitely notice the MSD with a 103mm. LT2's are limited to 95mm TB's where MSD's can run up to 103mm.

[Megahurtz]

On the stock cam, I would stick with the LT2 and port match it to a 95mm TB and then have the 95mm TB ported or get the 100mm eff TB from Solar. This is more air than the stock cam can even use.

The MSD is great and will make more power at the very top of the rev range, but you will trade that for a little bit of a loss in low end power(less than 4000 rpm). For a street car without a cam, it makes the car feel a little less torque-y and less fun, in my opinion.