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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
I've never used aftermarket header bolts before, specifically either "stage 8" or "split-lock" bolts. It would be nice to retire the old header bolts, make the engine pretty, and not need to check bolt torque ever again. I'm not really interested in ARP bolts just to throw $35 of bling at the engine, I'm looking for a functional gain.
Does anyone following have any experience or recommendation? Thanks.
Josh, I like the ARP header bolts I'm using them now with my Hinson headers. Not a fan of any other type of header bolts (like what you mentioned stage 8 or the other one).
If not ARP then get new GM OE ones but you know they will rust. ARP ones can be stainless or black (what I have) and won't rust.
I've never used aftermarket header bolts before, specifically either "stage 8" or "split-lock" bolts. It would be nice to retire the old header bolts, make the engine pretty, and not need to check bolt torque ever again. I'm not really interested in ARP bolts just to throw $35 of bling at the engine, I'm looking for a functional gain.
Does anyone following have any experience or recommendation? Thanks.
I love Stage 8 header fasteners. It gives you options to utilize an allen headed wrench or a standard socket/wrench.
I have been running Stage 8 header fasterners for about 12 years or so, and I have never had a bolt back out. Ever.
I love Stage 8 header fasteners. It gives you options to utilize an allen headed wrench or a standard socket/wrench.
I have been running Stage 8 header fasterners for about 12 years or so, and I have never had a bolt back out. Ever.
I've often wondered about them, but never used them. Always thought it looked like you need to be very precise about where to stop torqueing the bolt in order to be able to position that teardrop retainer appropriately to keep anything from backing out, even ever-so-slightly.
I've never had a header leak either, and mine have been on and off atleast 10 times now. If I was doing something about header bolts I would and did do the ARP bolts.
Sorry this project is taking longer than I originally stated. I have a customer car on my lift that was brought back to me with a valvetrain issue. (Last time I fix another shop's jerry-rigged setup...I'll only wrench on new parts that I recommend from now on, no ticky, no laundry). I'll have it completed this Wednesday, then I can get wrenching on The Underwhelmer.
In the mean time I bought some YT valve cover gaskets that space the VC 3/8" to make room for the shaft rockers. I picked up these LS3 VC's on eBay and some new AC Delco coil brackets separately. I had to hunt down some M6 bolts to retain the coils/brackets, so I went to the local hardware store and bought some SS button head Allen screws, just to clean up the appearance a bit.
Also, some new MSD wires I picked up from eBay. Red to try and make it stock appearing. You know, Cam Only There's a seller on eBay who makes the wires himself using all MSD parts, about $15 cheaper than retail. Hey, I have kids, and that's a trip to McD's so why not
Thank you for the advice on Header bolts. I have to decide if I'm ok with the looks of the stage 8 tear drop retainers, or if I just want to go ARP or Stock. If I go ARP I might do 6 point SS, a few less bucks than 12 point, but a few bucks more than 8740 (which rusts...).
I texture coat and shoot them low gloss black for most of the engines I build.....covers up all the ugly flaws in the cheapo pot metal the factory uses to manufacture them and looks ALOT cleaner. Even though it's under the red beauty covers for most applications, it's nice knowing it looks that good when they come off!
I texture coat and shoot them low gloss black for most of the engines I build.....covers up all the ugly flaws in the cheapo pot metal the factory uses to manufacture them and looks ALOT cleaner. Even though it's under the red beauty covers for most applications, it's nice knowing it looks that good when they come off!
=)
-Tony
Looks good Tony. I like the black. I might sand off the rough edges with a light grit sand paper, then media blast them. Or, try VHT wrinkle black paint and take my time.
I'm definitely going to paint the top 3 pedestal bolts on the MSD intake. They detract from the stealth theme. I'm kicking around the idea of sandblasting the GZ Motorsports vacuum pump. It's a semi-polished diecast finish. Sand blasted aluminum will look more "power steering pump/alternator".
Glad to see the Underwhelmer coming together. It looks like you opted out of the 447 cubic inch bottom end. Probably a good move at the end of the day.
I'm not aiming for SBE record or anything. My functional goal is to break 170+mph in the 1/2 mile. last year I got 162.9. I don't know if the current mods will be enough, so it's more of a long term goal that I'm going to work towards.
My intent is to make the most power I can but without too much compromise in drivability. Something short of max effort/impossible to cruise, something more than the previous combo. Jon blogged about his testing and trials to get over 700rwhp on his MCSS. The triple stepped headers, the Holley Hi-Ram, the sheetmetal intakes, that's some real dedication and it paid off for him.
Some differences between Jon's build and mine (there are more, but generally, exact same SCR, heads flowing close to same intake cfm, Tony's flow more exh cfm)
Jon
High rpm intake manifold
+6* Int / +7* Exh Duration, +.080" int lift +.040" exh lift
Triple stepped headers, larger Exhaust pipe.
Josh
GZ Motorsports Vacuum pump
Improved Racing crank scraper
LG Ram Air Intake
E85
I hate to even compare to Jon's build because his is just so well-documented and I have tremendous respect for his attention to detail.
I'm not aiming for SBE record or anything. My functional goal is to break 170+mph in the 1/2 mile. last year I got 162.9. I don't know if the current mods will be enough, so it's more of a long term goal that I'm going to work towards.
My intent is to make the most power I can but without too much compromise in drivability. Something short of max effort/impossible to cruise, something more than the previous combo. Jon blogged about his testing and trials to get over 700rwhp on his MCSS. The triple stepped headers, the Holley Hi-Ram, the sheetmetal intakes, that's some real dedication and it paid off for him.
Some differences between Jon's build and mine (there are more, but generally, exact same SCR, heads flowing close to same intake cfm, Tony's flow more exh cfm)
Jon
High rpm intake manifold
+6* Int / +7* Exh Duration, +.080" int lift +.040" exh lift
Triple stepped headers, larger Exhaust pipe.
Josh
GZ Motorsports Vacuum pump
Improved Racing crank scraper
LG Ram Air Intake
E85
I hate to even compare to Jon's build because his is just so well-documented and I have tremendous respect for his attention to detail.
A bit of attention to drag will have a much greater benefit over 150mph than adding HP. There was a great article in GM Hight Tech Performance (unfortunately assimilated in 2014) a few years ago about the LME Corvette testing in the GM wind tunnel in an effort to break 250mph in the mile. I'm not sure they accomplished that goal, but there were some significant learnings from the testing. I'll see if I can dig up that copy.
A bit of attention to drag will have a much greater benefit over 150mph than adding HP. There was a great article in GM Hight Tech Performance (unfortunately assimilated in 2014) a few years ago about the LME Corvette testing in the GM wind tunnel in an effort to break 250mph in the mile. I'm not sure they accomplished that goal, but there were some significant learnings from the testing. I'll see if I can dig up that copy.
I read that article. It was very informative. Little things like wheel covers helped drag, making a smaller spoiler helped.
Something to keep in mind though is that is 250mph air, and a standing mile. Aero compounds with speed, so we know there's no magical number at which point aero becomes an issue, just that it takes more power to push 200mph through air, than 190mph through air, and that the power requirement is far more than 180-190mph.
We know that 1/8 mile aero is relatively insignificant, with a spectrum of significance increasing from 1/8 mile drag up to the Mojave Magnum 1.5 mile.
I ran a Speed Lingerie bra on my car last year, I went to Joann fabrics and bought some matte black vinyl that my wife sewed over the front grill opening on the bra. I have to go braless this next year due to the LG Ram Air. I have toyed with the idea of clear covers for the wheels, but that's a bridge too far at this point. Also thought about fabricating some flat paneling on the underbody of the car. That I might be able to do with some sheet aluminum and some beer, and some patience.
Aero is key for flat out top speed, and it takes a lot of HP to overcome small details at 200. Let alone 300 and 400 where it gets multiplied exponentially.
There is only so much that can be done here with this car without a CF tilt front end.
Ive seen taped up gaps on the hood to fender seem, and like you mentioned, many run wheel covers, trying to make it slippery.
For under 200, id leave mine stock, if your trying to get from 230 to 240 then details become more valuable.
I read that article. It was very informative. Little things like wheel covers helped drag, making a smaller spoiler helped.
Something to keep in mind though is that is 250mph air, and a standing mile. Aero compounds with speed, so we know there's no magical number at which point aero becomes an issue, just that it takes more power to push 200mph through air, than 190mph through air, and that the power requirement is far more than 180-190mph.
We know that 1/8 mile aero is relatively insignificant, with a spectrum of significance increasing from 1/8 mile drag up to the Mojave Magnum 1.5 mile.
I ran a Speed Lingerie bra on my car last year, I went to Joann fabrics and bought some matte black vinyl that my wife sewed over the front grill opening on the bra. I have to go braless this next year due to the LG Ram Air. I have toyed with the idea of clear covers for the wheels, but that's a bridge too far at this point. Also thought about fabricating some flat paneling on the underbody of the car. That I might be able to do with some sheet aluminum and some beer, and some patience.
Aero drag is a huge deal even for bicyclist. Using the following inputs, it looks like you need to add about 65 hp to get to 170 mph. ceteris paribus.
Cd = .34
Frontal area = 22.3 sq/ft
Weight = 3200 lbs.
If you can cut the Cd to .32 and lower the whole car by 1 inch you would only need about 45hp.
I've never used aftermarket header bolts before, specifically either "stage 8" or "split-lock" bolts. I'm not really interested in ARP bolts just to throw $35 of bling at the engine, I'm looking for a functional gain.
Does anyone following have any experience or recommendation? Thanks.
I went with Stage 8 when I did my car. I needed new bolts, I bought Texas Speed headers and I could add the Stage 8 bolts for like 25 bucks, so I did. Do the locks work? I am sure they do(havent seen a bolt move). Do I think they are needed, not really.
If I could do it again I think I would go with ARP for no other reason than I used a bunch of other ARP bolts in the build and they are definitely quality. Nicer than Stage 8? I dont know.
I have had zero issues with the Stage 8 bolts though. Checked torque 3 times and only after the first heat cycle did things change, but thats expected. At the 500 mile mark, they clicked the torque wrench with no movement.
IF you go with ARP, I would personally do the 12 pt vs. 6 pt. In my head the 12 pt makes more sense in a confined environment if the socket isnt lined up just so or if it slips off you dont have a huge amount of "clicks" to get it lined back up.
10-20-2016, 02:43 PM
Header Bolts?
There's a seller on eBay who makes the wires himself using all MSD parts, about $15 cheaper than retail. 
Hey, I have kids, and that's a trip to McD's so why not
