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Get a different tuner. No disrespect if you tuned it yourself, but there are different parameters that tuners don't know about or don't want to take the time to adjust because it is very tedious when you turn the A/C on. I'm not saying prefect but undrivablity is out of the question you can diff make it better 100% make it better.
I hear about this issue so offend. It takes time a patience but you can make it more drivability with patience and time. Like i said, not perfect but way better than your "It's ******* undrivable at low rpm with the AC". JMO. The tuner told me it was impossible to get drivability on my engine. Well, Bret talked me into buying HPTuners and learn and you will make it better. And sure enough its spot on. But i had to buy new eyeballs from the black market from researching the internet, but if there's a will there's a way. It was extremely frustrating but i kept at it and the finally outcome was very satisfying that i proved a professional tuner that it couldn't be done.
Probably a good example of grabbing the bull by the horns. Definitely not looking to offend. Hopefully encourage action toward striving for the highest standards.
A hundred years ago, a wise ol’ man told me “Don’t take ‘no’ for an answer ‘cuz ‘can’t do’ never did anything and always has a treasure chest full ‘o nutten to show for it!”. I have failed more times than I can count but giving up or giving in isn’t in the vocabulary. Thanks, Dad!
Great job on the post, Brett! I went through this thing top to bottom and boy did this ever bring back memories! Lots more with the advent of consistent runner and CC design cylinder to cylinder, and that continues the thought of just scratching the surface. Helluva build and love me some big liter! Different day and time and I would have had to get a little closer sniff of the 427 build of the young man in WA. You both have me back in my personal library looking over and adding to my knowledge base of rotating mass, volume, timing aspects of split cam profiles and the impact on VE, etc.
Thank you for being where you are in this place and time. Hope the family is doing well and you all have a good week!
All this cam talk made me come out of stalking this thread to gunking it up instead ahah
I have the Summit 8721r in my 11.3:1 408: 247/255 .625/.615 113.5+2
It's ******* undrivable at low rpm with the AC on, but she absolutely rips from 4-7k rpm. Just don't idle around a parking lot in 1st with the AC on lmao
I'm back with my dipstick cam designs again. Soon to choose a grind and send it to be cut - I PROMISE. Though I do want to verify the actual CR range on the car first. I don't need to know a wicked precise value. But I do want to know if it is near the 9.5 I am blindly guessing at or 8.5, or 10 for example before I end up with results not as expected.
This time I ran it through Claude Sonnet LLM for ideas and once it was somewhat dialed (far more consistent than Gemini free version) it looks like I do not need as much exhaust duration as I have. I dialed that back, re-spaced the LSA to keep a barely negative overlap and it paints a pretty good picture for my goals. It picked up more top end power than my prior grind as well as now more torque than the Honey Badger which has a much tighter LSA.
For fun, if anyone is interested here is the working file I've been using. Under Cam Specs it shows a smattering of different information. And I need to reiterate that this should all be taken as loose reference only and not true to life. I tried to hedge my bets by telling it to presume a Mustang dyno with historically lower results.
Inside for the engine / cam comparisons you will find:
Track Zero - my prior grind
TZ/C1 - the likely final version of the Track Zero
Honey Badger on my 427
Stock LS7 (tethered by real dyno ranges and head cfm)
Ray's Z06 (mapped to dyno values as well as having his head flow charts input)
LS1 Modded was my old coupe with shorty headers, BPP vortex, full exhaust etc on a dynojet.
P-1SC is the car above but with 9.6psi SC on a hub dyno (peak hp entered only)
Track Weapon on an LS6 shortblock with LS6 heads milled 25 thousandths, long tubes, high flow cats, oem exhaust but tuned/dyno'd on rollers with cutouts open. Tethered to the peak numbers but also the full curve shown.
Then of course the TT Z06 modeled as HPT 0 / 4 / 6 / 8 by psi ranges. I am toying with the idea of adding a bypass air system as well to run it full "NA" mode down near 1psi but I won't worry about that until I get the thing running and get some baseline data first because, again, these are just pretty pictures which cannot substitute for real world results.
Download the file. Run it in your browser. Click on the ones you want to see or hide.
Cars I've got. King of stupid expenses here whenever I've been working, and mostly before I got married. We're both cooling our heels, not for cause, and we've got a lawsuit for their firing her illegally (blatantly) while she was on pregnancy leave, but she and baby are medically complex and burning through savings at nearly 5 figures some months. The stress is real.
Once I get to working on them both again I'll have a few others for sale:
Ported LS6 intake
BBK 80mm tb
BC BR coils
A&A secondary drive kit
Custom leather sport seats
FIC 1650 injectors
Cars I've got. King of stupid expenses here whenever I've been working, and mostly before I got married. We're both cooling our heels, not for cause, and we've got a lawsuit for their firing her illegally (blatantly) while she was on pregnancy leave, but she and baby are medically complex and burning through savings at nearly 5 figures some months. The stress is real.
Tusc, Good thoughts & prayers to you and your family.
Really enjoy your posts.and you're an inspiration here !
I couldn't answer that directly, but I'd wager that's outside the efficiency curve.
The problem I've found, rather the education I've recently acquired, is that CID is a real magnifier for turbo setups. Cam? Heads? Who cares. Once you enter boost it is just the turbos making the power. And the CID sets the bottom rung of the dyno curve. Had I known this might be the end result when I started out building an SC car on the other thread but ended up twin turbo, I absolutely would have gone for a basic 5.3 and nothing special. Just ride the turbos. My version of having my cake and eating it too would be a smaller engine which could make just 450rw for super dumb/easy throw it anywhere driving when wanted, and then just turn up the boost at the gate depending on my need or preference. My HPTs will make whatever I could want. More really. That 402 even hugging the taps and keeping the boost as low as possible is still going to be pretty rowdy. Not outside my comfort zone at all. But not quite the wide range I'd really enjoy in a turbo "do anything" build. That one at no boost is basically this 427 as it will be when done. More or less.
If you want positive manifold pressure.... There's always the F-1R for you!
I am now richer by exactly one original Tiger Shark nose.
Not immediately, but the plan is to eventually return this car to the appearance before the original owner sold it be reuniting a tiger shark nose with the tail.
However... While I do like the ACP Magna Extractor hood... C7 Carbon is planning to finally produce their C5-R approximated hood for our cars and wouldn't that be a proper homage to the engine itself?
I called Cam Motion to place the custom cam order finally. It makes perfect sense of course to be told that the majority of their business falls in the 110 to 113 range and they have very few 116 grinds or above which they could possibly cut safely to my 120. I rightly guessed the issue being that they don't want to cut deeper than the heat treatment. This all makes sense beciguys buying cams usually go for the big lope and lower LSA which is the opposite of my polite street manners build. The only bell which rings in my head is 'what about guys with blowers?' who ought to be in my general range often enough. The hickup is their trying to do right by me and also keep the price at the $400 regular core level, but it might end up being another 8620 core for $600 to get it done.
BTR is already closed or I'd call them tonight as well. I'll ring them up tomorrow.
