Hi everyone,
I believe I will be helping more than a few people today with this write up as there is much to learn for C7 Z06 owners who want more out of their cars. Regardless of what I write here - do your due diligence - the information is out there but isn't the easiest to find sometimes...I thank Manny Dasilva and Dave Rempel - with the entire Dasilva Motorsports Team for making this happen...it was a cool journey...and it ain't over yet lol...
Background:
I was not satisfied with overheating issues of these cars - nor the cause of this overheating - the absurdly tiny Eaton TVS 1740R blower. I am a turbo guy - and I found SC's pretty frustrating.
I first tried upgrading this setup with IW 18% lower, a 2.38 upper along with AR 1 7/8" Headers and a Halltech CAI. I knew over spinning would make an already poor cooling situation worse - so I added a CR primary rad, GM secondary rad, Dewitt heat exchanger/intercooler and oil cooler.
A billet 160 thermostat and CR catch can rounded everything out.
Despite all of this cooling, the magma hot SC and lack of circulation in the engine bay still made for over heating so I added a one nozzle (15) Alky-control solution. This made the greatest difference - and in 90% of the situations - no issues. That said, in 95-97+ F temps and humid weather - with running the car in a spirited fashion - the lack of circulation would become too much - sometimes vaporizing the meth in the lines before it even reached the engine.
So I had to make a decision. Do I try something different - or get rid of the car? I really liked the car - and to be fair - the DMS 700 package did what it was supposed to - but GM design issues (lack of engine bay heat circulation and ultra tiny SC) got in the way. I made 680/716 at 14 psi on this build and ran a 135 MPH trap in the 1/4, all in 100+ F heat. No cam. That was healthy power. With a tire, this setup was very driveable - but on the crappy for street use sport cup 2's (which need constant heat - and cool very quickly unless under constant load) - I was spinning quite a bit with the tuned, over-spun low-end roots-type SC as well as an already torquey LT4.
My Decision:
I believe we were the first C7 Z06 in Canada to try the F1A procharger. I picked this particular PC due to its "goldilocks" size. Bigger than the P1SC and D1SC but still not the top like a F1R or X. I don't count F2-F3 PC's as these are race-only solutions and I wanted a street car. The toughest decision was whether to get an F1A or F1A-94. Jeremy at Procharger was very helpful and took me through my options. It really came down to this; do I want to crack the motor and add a cam as well as forging the engine to allow for more RPM or not?
If yes - then the F1A-94 is for me. I decided against this after speaking with my Builder, Dasilva Motorsports - which I will get to in the Challenges section. SO I stuck with the F1A.
This was a great decision - for me. I want to state here and now, that I am not here to promote anything. I am not sponsored by Procharger (although with this write-up, maybe I should be lol). I am not saying what is "the right way" - only what I have found along my personal journey building this car. Opinions may vary. Find your own answers.
Challenges:
I spoke with one of our CF members who has the F1A - but without meth or a cam. I wanted to stay on this path as well - bolt on only - but with meth. Some may say it is a waste - and for what this blower is capable of - it kind of is. That said, I like over-engineering, and knowing I am well within tolerances. What I found out was there were some significant challenges with the C7 Z06 itself (which I already found as a manual car in my earlier setup in regards to its tune) - that would cause some limitations.
Fuel.
Although our DI pumps put out an insane 3000 psi - it would seem that the stock mechanical pump is a limitation. In fact, DI itself is somewhat of a limitation. If you do your research as I did - you will find that different shops are encouraging different solutions; port injection with the DI, and port-meth injection. As of today - there are no fuel system upgrades specifically for the C7 Z06 DI system - although I have been told that they are on their way...in the very near future.
What many shops have done is use a cam and corresponding cam fuel lobe - to help bypass this fuel issue. This does work. So if you want to overcome - at least to a point - these interim lack of fuel system upgrade issues - and make more power to boot - this is it. I did not want to crack the engine - so this was not a solution for me. My Tuner, Dave at Dasilva Motorsports had to do a great deal of tuning to work around this issue as well as the duty cycle - which is read by HP Tuning gear in a certain way. It seems that 49%+ duty cycle is really 100% so you need to figure out through a great deal of testing how to bring that down but still get the proper fuel to the car. This is beyond me - but I am sure Higg's can discuss it if he comes on this thread...DI is tricky; HOW and WHEN it sprays - - not just too much or too little - - is a major issue.
This is also why I picked the F1A versus F1A-94. I wasn't adding RPM and building the motor to help compensate for that. I wasn't even using a cam. So the F1A was more than enough.
The Outcome:
Dasilva Motorsports came through. As their first DMS 800 package - I was extremely happy with the results. With my PS2's on the car we couldn't get a good pull on the dyno (dynojet)- so I borrowed the owner - Manny's PSS's and we put down a best ~782/714 on pump gas with dual nozzle alky-control meth. This was at only 14.78 PSI mind you - so it has a lot left in it.
As you will see from the graph - as Dave was adding timing, the green run - which was the best - had a sudden fall off right at the end of the pull. This was due to the lower charge pipe popping off. If you follow the line - it was on its way to over 800 whp. I believe that this combo is 800ish at the wheels as it stands today. We will do another pull later on. Torque is about the same as my DMS 700 package - which was a pleasant surprise - only coming on later.
The Review:
This is the setup I was waiting for. I was worried about lag - but as my GTR Builder stated when I took him for a ride - "the displacement hides it well." Power comes on in the high 3K RPM and pulls linearly all the way to redline - and it pulls HARD. Herein is where I see what Jeremy from PC was saying. This unit would be so much happier with an additional 1K+ RPM. I am just touching the potential of this centri - and it handles "full power" as we have it set without any difficulties at all. This setup is much more driveable in my opinion - with power coming on smoothly - although on stock crap PS2's you will still break traction in the upper RPM of 2nd and 3rd (and most of 1st lol).
Seat of the pants and I believe this setup will comfortably trap 140+ MPH. I will find out.
And it's cool. I mean colder...
No more heat. With my cooling mods - which all (minus the Dewitt heat exchanger and Halltech CAI of course) still fit with the F1A in place. It pulls consistently time and time again. It was over 90F this past weekend and I had ZERO issues.
The sound:
I was warned that there is no Helical gearing for the F1A - so it may be louder - and...it is. BUT. The whooshing of the massive blow off valve is what you hear - not the PC itself. It has a very cool - "turbo" whistle and is not actually very loud. The blow off - has a good ending as well. When you are driving in higher RPM's, whenever you let off the gas - you are going to get a "Whoosh" from the blow off. BUT - when you are cruising in 7th - for example - there is no sound. SO when you are driving with intention it sounds like the modded sports car that it is - and when cruising - quiet as a mouse. I was very happy with this. I kept my stock exhaust so I could switch to "stealth" mode in tour whenever I wanted - and this helped with that when I just want to cruise with family.
Overall - this is the package for me. I cannot give it enough praise. It is legit quick now (very similar to my GTR when it was at 800 awhp on pump gas). With a tire it would be a serious roll contender and it's launch off the line is pretty impressive as well (I worried about 60 foot with the higher power band - but the engine helps compensate for that here as well). It drives so well. Very smooth - and the power rush is really thrilling - every time.
With less concern over fuel delivery - I think we could up the boost/timing and get over 800 whp without much difficulty - so I am excited to see what these new fuel mods are and what they will/can do. The F1A has that room to grow and is such a nicely made product. No drilling or cutting.
I am sharing a drag pack with another customer and we will be off to the track for some testing. Road course is another area most people have poo poo'd when you get a PC. I believe from what I felt that I will be okay here - but I will have to be careful when the power comes on lol. This is a GT car for me - not a drags car. It is an all rounder.
For the price and the way it drives - all round - this is the perfect setup for me...
View attachment 6404
View attachment 6405 View attachment 6406