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Natural Aspirated Positive Boost

TODD L GRIFFITH

Well-known member
Joined
Jul 12, 2001
Messages
1,120
Location
Middleboro, MA
Corvette
99' MR Coupe, 04' Silverado 03' ZO6 Sold
I knew the old Predator would be good for something. :L My Z is tuned with EFIlive, let's get that straight, but you can also use a Predator to monitor real time MAP data while driving if you don't have the real tuning software. I have been monitoring my MAP pressure on my bottom feeder Vararam Widemouth. It sits below the nose in front of the spoiler exposed to the incoming air. I'll post some pics. depending on any interest or discussions. If you turn the key on with no start, the Predator will give you an atmospheric reading to the nearest tenth. ex. 14.7psi. Start the car and at idle I have been seeing 8.7 - 8.8psi (+/- 5.9psi. below atmospheric or negative pressure) Take it out on the road and see if you can make the 14.7psi. (1 Atmosphere) back at WOT. Anything above 14.7psi. is positive boost. ;) I've been seeing a consistant 14.8psi., .1psi of boost @ 6800rpm. Given the pressure drop of the filter, this is a good thing for air filter efficiency. :) If you have an old Predator lying around, check it out to see what kind of MAP numbers you can produce.
 
Todd, not trying to hijack your thread, but I have a few questions, since I noticed you have modded your car. I am planing to go AFR205, with a 224/228 cam from Tony Mamo at AFR. He will be also porting a fast90/90 combo for me to match the heads. I will be upgrading the radiator to a dewitts all aluminum, since I live in the south(FL) and it's hot here and my temps rise in traffic all the time. My thinking is this, should I do:
Fidanza flywheel
ported oil pump
underdrive pulley
ATI damper
fuel injectors
Meziere pump
My current setup is LT's with Vararam B2. My thinking is since the water pump, belts and hoses need to come off anyway, and i am paying for the labor and tuning, might as well smack the new stuff on at the same time.
Is there anything else you would consider to do at the same time? timing chain etc? Could you suggest what I should do?
Herb
 
No, your not hijacking at all. Thanks for responding. I think you are on the right path with doing a cam. A cam and heads at the same time is a huge increase in power, so you will be happy for sure. I would recommend along with those mods. is a set of 36# fuel injectors. This is 36# @ 58psi. FAST makes injectors and I believe Tony has had a set of them on his own car, so ask him about them. You can also buy a SVO 30# injector, bench tested at 43.5psi. This is equal to a 36# with your 58psi fuel pressure. That is the first thing. A good valvetrain is real critical. If your lift is at .600" or under, definitely go with a COMP 918 valvespring if you can. This is made to rev. 7200rpm and without any valvefloat!! Chromemoly pushrods are another critical recommendation, a must. You can reuse your stock 1.7 ratio rockers. One thing you might want to consider is milling the heads if you have no plans to supercharge. This will raise your compression. Removal of approx. .006" per cc of reduction. The last thing is dyno tuning. You won't be disappointed with a tune using LS1edit, or EFIlive. HP Tuners is good too.
That's all I can think of. Remember to use white ThreadLoc on those water pump bolts. There are other little details regarding timing chain, damper bolts and what not. If you need more info. ask me anything.
Thanks,
Todd
 
Todd, thanks for the reply! Ok, so:
Chromely pushrods
Comp 918's
SVO 30#
Done. Now, should I go with a single or dual timing chain, and what's the difference? Ported oil pump? Do I need the porting? what does ot do?
Finally, should i change the flywheel, or stock?
herbie
 
Todd, thanks for the reply! Ok, so:
Chromely pushrods
Comp 918's
SVO 30#
Done. Now, should I go with a single or dual timing chain, and what's the difference? Ported oil pump? Do I need the porting? what does ot do?
Finally, should i change the flywheel, or stock?
herbie
I would get the double roller timing chain, for insurance. The oil pump can be reused as long as you get the bleed off shim from SLP. I would change the flywheel if you are changing the clutch. This is a 6 speed correct?
 
I would get the double roller timing chain, for insurance. The oil pump can be reused as long as you get the bleed off shim from SLP. I would change the flywheel if you are changing the clutch. This is a 6 speed correct?


Yes, 6 speed. The car has 60k miles on it. Tony Mamo is porting a LS6 oil pump for me as well. He recomended .080 chromemoly pushrods, but said to stay with the his upgraded springs, and stock rockers. I am not sure if I should change out the clutch and flywheel at the same time, but 60k miles...
which clutch, LS6, spec? What I am really confused about is the combo of the Mezeire and underdrive pulley. The Mezeire WP319 is the model for our cars, and it comes with the idler pulley on it. Then with the underdrive pulley, can i use stock belts? Will need to dig into this further. Merry christmas!
Herbie
 
Yes, 6 speed. The car has 60k miles on it. Tony Mamo is porting a LS6 oil pump for me as well. He recomended .080 chromemoly pushrods, but said to stay with the his upgraded springs, and stock rockers. I am not sure if I should change out the clutch and flywheel at the same time, but 60k miles...
which clutch, LS6, spec? What I am really confused about is the combo of the Mezeire and underdrive pulley. The Mezeire WP319 is the model for our cars, and it comes with the idler pulley on it. Then with the underdrive pulley, can i use stock belts? Will need to dig into this further. Merry christmas!
Herbie
Here is your situation, once you change the cam, install new heads that are better than stock c5ZO6 spec., and run long tubes, you are looking for a clutch that can handle your 550hp and 520lb./ft. of torque at the flywheel. The other issues that arrive are drivetrain and tire types. My clutch can handle 1000ft./lbs of flywheel torque and I'm only half that. Drivetrain mods. are replacing the half shafts while you do the clutch, and think about a transmission brace while you are there. You will be happy riding around with 200hp over stock. I'll tell you what it is like. Imagine dropping it down to 5th gear above 85mph, then have the feeling of being shot out of a cannon at 150mph to see the top of 5th, knowing you have enough torque and another whole gear to explore above 175mph. This is what you may expect depending on cam and heads.
You won't be able to use the stock belt, because you are eliminating the steering pump pulley from all the drive belt accesories. :) Let me know all the good details. I'm sure Tony already has in mind all the numbers on the stuff that works, to provide you with excellent valvetrain geometry, where peak power is made. You can't go wrong. Keep me informed of the good stuff happening.
Todd
 
which clutch, LS6, spec?

Here is what I did.

I have the SPEC Stage 3+ that is good for 850rwt, or 1000 flywheel like I said, I'm half that. The reason why was, the regular SPEC Stage 3 (not the plus) has some chatter issues and the engagement isn't as sweet as the plus. I did my flywheel and new pressure plate at the same time. Again, you will need the hydraulics on a clutch swap on a 99' C5 in addition. My flywheel is lighter than stock, but it isn't a lightweight unit, but it is balanced which it key. I still need the mass of a heavier flywheel to get me out of the hole.
Merry Christmas to you and yours,

Todd
 
Here is your situation, once you change the cam, install new heads that are better than stock c5ZO6 spec., and run long tubes, you are looking for a clutch that can handle your 550hp and 520lb./ft. of torque at the flywheel. The other issues that arrive are drivetrain and tire types. My clutch can handle 1000ft./lbs of flywheel torque and I'm only half that. Drivetrain mods. are replacing the half shafts while you do the clutch, and think about a transmission brace while you are there. You will be happy riding around with 200hp over stock. I'll tell you what it is like. Imagine dropping it down to 5th gear above 85mph, then have the feeling of being shot out of a cannon at 150mph to see the top of 5th, knowing you have enough torque and another whole gear to explore above 175mph. This is what you may expect depending on cam and heads.
You won't be able to use the stock belt, because you are eliminating the steering pump pulley from all the drive belt accesories. :) Let me know all the good details. I'm sure Tony already has in mind all the numbers on the stuff that works, to provide you with excellent valvetrain geometry, where peak power is made. You can't go wrong. Keep me informed of the good stuff happening.
Todd


Got it. I think your driving around in a spec stage 3, how does that feel?
the DTE, is a good idea from what I have heard. The half shafts, need more info on that mod. Another one I hear is the hardened torque tube, my question is do need all this reinforcement for a daily driver? This car seldoms see's track time except for my local club events, and even that is not hard driving, for long periods of time. I would like to build a dedicated track car in the future, once I get pass this one. I just want a daily driver, that drives with stock manners, but when I mash it it goes like hell! I like your setup, tell me about your ride, how is it on the streets?
Herbie
 
Todd, sorry I see your previous post you already told me stage3+. I am going to go that way.
Herbie
 
how is it on the streets?

Like driving an Impala with a twitchy throttle. :rotfl
If you don't do anything like half shafts or brace it isn't a problem as long as you treat her nice. The clutch is a have to, unfortunately. At 4800rpm my stock clutch was slipping which is the torque peak. I think the stock clutch is only good for 450-500hp and torque. Some people get the c6zo6 clutch.
Todd
 

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