Nothing ground breaking here, but as I made my way through this project this winter, I definitely noticed a serious lack of DIY threads showing Paxton installs. I basically found Frog's and that was it.
I tried to keep things detailed to help others out who are considering tackling this themselves, but at times I got lazy or forgot to take pictures.
Don't except it to be as thorough as Dave's DIY threads You also may spot a spec of dirt or two on mine.
Back in August, I decided to sell my 2008 Viper and look for something different. My 2008 was low mileage, black, and I was always worried about it wherever I went. I decided at that point it was a waste to have a car that sat in a garage and that I never drove, albeit an expensive one.
Heavily looked at buying a Gen 2 split-bumper Camaro for a pro-touring build, an E36 M3 with LS swap, buying a high mileage lotus to build the crap out of, etc. I even was very close to buying a FF GTM kit at the prodding of my wife, but decided I wanted something to drive within the next 5 years so I ruled that out.
Ruled out the 2nd gen Camaro because I didnít want 2 cars from the same generation, ruled out the E36 LS because it wouldnít make enough power (very difficult to fit a turbo although it would still be a blast NA), ruled out the Lotus because I know I would probably die in a crumpled tiny ball of aluminum and fiberglass, and finally ruled out the GTM because of the amount of fiberglass body work it entails, which just didnít sound like a fun project.
In owning my 2008 Viper, I started to really wish I had a 96-99 Gen 2 instead. Sleeker and more classic body style, easily modifiable (compared to the Gen IV), and it would be old/cheap enough that I could drive it anywhere without worrying, etc.
I listed my Viper for sale, and a few days later I had a guy from St. Louis offer me his Gen 2 + cash for my Gen IV. Within 24 hours he was at my garage with cash making the swap.
Car upon arrival. 1997 Time Capsule with 17Ē gold wheels.
It has gold wheels and badges because it was ordered with the Gold Edition exterior package. Only 7 GTSís were made like this. I donít plan for this car to ever be at Barret Jackson, so I doubt it will matter, but it still makes the car a little more interesting.
I started with the simple mods, Eibach 1Ē lowering springs, new EBC red pads (had really aggressive track pads on it that squealed like crazy), short shifter, tint, and some gunmetal plastidip to make sure I liked the color combo before ordering aftermarket wheels.
2008 SRT10 Coupe- Black w/ Silver stripes - Sold
1997 Viper GTS- Front Mount Single Turbo
The tail light tint turned out a little too dark for my liking so that will be coming off. Oh well. It was worth a shot.
Next, I wanted to update the look of the car by getting some new, larger, less gold wheels. Ended up going with Forgestar F14’s in a gloss gunmetal. Also decided to lower it a little more with ĺ” shorter spring caps. For tires, I went with Nitto Invos.
Wheel size is 19” all around, with 345’s on the rear and 285’s on the front. Really wishing I would have went with a drag radial on the rear, but oh well. I probably will burn through the Invos pretty quickly, and street tires should lessen the risk of me snapping my stock halfshafts for the short term.
After fitting the wheels and driving a few miles across town, I immediately noticed I was rubbing the rear tires on any sort of bump. Decided to trim the inner fender lip a little bit.
You can see the black residue where the tire was rubbing.
Good as new.
Latest development is that it is now rubbing the actual inner wheel well liner. I may try to shim it up to gain some clearance, or I will have to raise the car back up .5” or so I’ve actually considered heating up the plastic as well and pushing it in while it’s melty. While I love the look it’s currently at, with doing a half mile event in the spring, I can’t take a chance on it hitting my tire while doing 160+ and possibly gashing or blowing my tire out.
Now for the fun stuff. One of the main reasons I bought a 96-99 Viper is because they were made with forged internals from the factory. Because of this, you can run a good amount of power or boost without building the short block. I decided it was time to add some boost.
I heavily contemplated going twin turbo, but after crunching numbers in an excel sheet, it was clear that a supercharger and supporting mods was already going to be maxing out my budget, and just couldn’t justify the extra cost a TT would run me. The nice part is, most of the money in these builds is not actually the supercharger itself, but all the fuel support, valvetrain upgrades, etc to handle the boost. In the future, if I get bored, I can sell off my supercharger kit and buy a couple turbos and not spend a fortune.
Decided to go with a centrifugal Paxton Novi 2000. I got it slightly used from a fellow Viper owner who decided to upgrade to TT. This kit is put together by Paxton but the head unit is a Novi 2000. The kit comes with an air to water cooler. In addition, I will be adding meth injection to keep things cool and keep the heat soak to a minimum.
First things first, I needed to get everything disassembled and ready to work on.
Got her up in the air.
Intake assembly removed.
In the dining room for safe storage. LOL. Luckily we are in the middle of a major remodel so no big deal.
Next, time to start tearing down some stuff in the engine bay.
First up, the shock tower brace had to go to make room for the blower. Also, drained the coolant, pulled the top radiator hose, crank pulley, radiator shrouding, power steering bracket, and unbolted the steering oil cooler.
Starting to look like a blower could fit in the front.
Also had to pull the windshield wipers and cowl to have access to the intake manifold and fuel supply lines.
Next, depressurized and unhooked the fuel supply line, removed all 10 injectors, and unmounted all the other random things attached to the intake manifold (IAC, throttle cable and bracket, spark plug wire mounts, PCV, etc).
Upon removing the intake manifold, found a fresh surprise underneath from my car sitting in my garage for the last month without running.
A nice mixture of acorns, attic insulation, mouse poop, and best of all, a bunch of the poisonous pellet food I left for them to eat in the corners of the garage!
Lastly, pulled the valve covers off. They were starting to chip and corrode from the heat cycling over time so I figured while I have everything apart, I would have them re-coated.
Powdercoat chipping off from the magnesium valvecovers.
Next up, I dissembled the dual throttle bodies and other features from the intake manifold to send everything off to powder coat.
In preparation for the supercharger, I needed to pin the stock harmonic balancer to the crankshaft. The stock balancer is not keyed and can therefore spin when under increased load (read: extra belt pulley). You would think Chrysler would at least be smart enough to thread the balancer opposite of the rotation of the engine, but nope. If it starts to loosen, the rotation of the engine will spin it right off the crank. It happens fairly often.
The simple solution is to drill the balancer and crank, and insert dowel pins to keep it from spinning and loosening the bolt.
Here’s a picture with the balancer bolt already removed ( a real treat at 250 Ft-lbs of torque stuck on there for nearly 20 years). You can also see there is barely any room to work with the steering rack in the way.
Used my handy dandy air gun with a swivel (yes I know that isn’t an impact socket).
Drill template bolted to balancer
Holes drilled through balancer and into crank snout
Rolled shear pins ready to insert.
Bolt back in and torqued.
Crank Pulley Install
Next up, needed to install the new crank pulley setup with the extra 8 rib pulley for the supercharger.
Installed back onto the balancer and ready to drive some power.
Needed to add a fitting to the oil pan for the oil return on the supercharger.
Oil pan before.
Used a Rota Broach to cut the hole. Basically a super slick hole saw made for sheetmetal. Cuts like butter.
Next, tapped the hole. Of course didn’t have an NPT tap kit because I could own every tool on earth and STILL never have the right tool when I need it.
Power Steering Pulley Swap
Stock Gen 2 Viper power steering pulleys are notorious for being a giant piece of crap. They are plastic and have been known to randomly break in half and fall off the car in the middle of traffic or cruising. While I had everything apart in the engine bay and easy access, I decided to upgrade to a billet version.
Another simple upgrade while I had everything apart. I noticed last fall my car would get pretty hot in city traffic on a warm day so I figured it was worth the upgrade. Replaced all my gaskets as well for peace of mind since they are nearly 20 years old.
I noticed after removing the intake manifold my crankcase ventilator had a little leak around the seal. Replaced it as well while I was in there. You can see the old one was pretty deformed.
New 170 thermostat, crankcase ventilator grommet, and thermostat housing re-installed.
Next up, needed to re-install the intake manifold. The gaskets fell apart as I took the manifold off so replaced them with new.
Also cleaned up the valley as much as I could from the mouse nest and crankcase ventilator leak. With that, time to install the gaskets and drop on the manifold.
Before putting the throttle bodies back on, I gave them a good scrubbing and cleaned the inside mechanism and surfaces with throttle body cleaner. Also for good measure went with new gaskets. No pictures, but I cleaned up the IAC valve as well while I was at it. I noticed the idle was a little rough at stop lights when I bought the car so I have a feeling a gunked up IAC valve was a contributor.
With the manifold back in place, I moved forward with installing my new top feed injectors. Siemens Deka 60 lb. I bought these used so I decided to throw on new O-rings for good measure to make sure they don’t leak.
With the new injectors ready for install, I dropped them in and installed my new -8 polished fuel rails. The stock viper fuel system sucks and is a single -6 supply which feeds into the back of the manifold and flows through side-fed injectors. The system is also deadheaded and the pressure is controlled via the pump module in the fuel tank in the rear of the car. No Bueno for a performance application. I will be adding an Aeromotive FPR in the engine bay with a -6 return line to the tank.
Power Steering Line Modification
In order to keep the stock power steering lines clear of the supercharger belt, I had to change out the stock hardline and re-route a new flexible line facing back towards the engine block.
Updated adapter fitting and line
Also replaced the return hose with some brand new rubber for good measure.
With the boost I will be adding, I needed to provide some more fuel. As I stated before the stock fuel system is garbage. The FPR is built into the fuel pump module. In order to upgrade the pumps and supply line size, it’s easier to just replace the whole module with an aftermarket unit.
Gas tank is located in the trunk. Pretty convenient setup with an access panel under the carpet to get to the fuel hanger. Somebody decided to glue the carpet into the car which was very annoying though. And the access panel is riveted instead of bolted :/
To make things easier in the future, I replaced the rivets with some bolts and spring clips.
Removed stock fuel hanger from car. Gotta love getting dunked in gasoline!
New billet fuel hanger with dual Walbro 255’s. The second pump only kicks on under heavy acceleration.
Already setup for a -8 supply and -6 return line with AN fittings.
Next, needed to move some of the features from the stock module over to the new aftermarket unit. Rollover valve, fume vent, fuel level sensor and float, etc.
Float on stock hanger.
Float wiring cut and float removed.
Float level sensor mounted and wired into the new module.
New wiring harness with relays to control the pump flow under throttle.
New fuel harness wired into battery and stock harness.
For fuel lines I went I decided to do it right once and run PTFE lines and Fragola PTFE re-usable fittings. I wanted the hose to be stainless braided and the fittings black so it worked out well aesthetically as well. Holy crap this stuff gets expensive fast! I donít even want to talk about how much money I have in fittings.
Pressure regulator is an aeromotive unit with dual -10 inlets and a -6 return port. Fuel filter is a fragola with -10 inlet/outlet.
First step was to find a mounting location for the fuel filter. I needed to figure out a simple way to mount it in the trans tunnel.
Grabbed a piece of aluminum from Farm & Fleet and made a quick bracket that would squeeze the filter when installed.
Now time to measure out my lines and choose fittings.
Fitting install for PTFE fittings:
All the lines crimped and ran. Use a -8 to -8/-8 Y-block to split the flow near the firewall.
Still need to figure out where to mount this guy in the engine bay while keeping the lines clear of interference and clean looking.
The Viper V10 is a low revving torquey vehicle, not much of a high revver. When you add boost to the equation, you add the chance of getting a lot of valve float at the upper end of the RPM range 5500-6000).
From the factory, the stock valvetrain has dual valve springs but simple, stamped rockers on stud mounts that cause a lot of friction and heat. Also, the stock 5/16 pushrods like to flex under high RPM adding to the valve floating issues.
To combat the valve float and the chance of excessive valvetrain wear leading to a dropped valve, I decided it was necessary to make some upgrades.
Stock Valvetrain with crappy stamped rockers
First step, removed all the rocker stands and rockers for each cylinder along with the stock pushrods.
Next, swapped out the valve springs for some COMP dual springs which are a little stiffer than stock. Stock springs after 20 years Iím sure have softened up as well. Also changed out the valve seals with a brand new set of OEMís while I was in there.
When pulling the spark plugs I found there was a ton of rocks/dirt/debris surrounding the plug holes. This car was definitely tracked in the past so Iím guessing it went offroad a time or two. Came up with this little gizmo to suck the debris out of the plug heat shields LOL.
For the new roller rockers, I went with T&Dís. These have a 1.7 ratio compared to the stock which have a 1.6 ratio. This will give my cam a little more lift. Should give me a slight bump in power but I mostly did it for the peace of mind. The 708 cam that came in the 96-99ís is already a pretty lumpy cam. These should only help. Lastly, they use ball bearings on the actual rocking arm and on the rocker tip instead of the friction fit used on the stamped stockers.
I picked up the T&Dís slightly used (about 3k miles on them). The idiot who sold them to me decided it would be a good idea to package them all in one zip-lock bag. Zip-lock bag + 5 day shipping + alumidized parts = scratches. Oh well, no one will ever see them but it bothers the OCD side of me.
Cleaning up the oil and gunk on the rocker stands. These are made from a single piece of billet aluminum to distribute the load stress across the head.
All cleaned up.
New COMP valve springs on the left compared to the old on the right. Same style just a little stiffer.
Valve holder and air compressor line hooked up to hold the valve up while swapping springs.
Compressing the springs.
Stock spring removed. You can see the valve seal here.
Valve seal removed.
New valve seals.
All the stock springs removed.
New ARP hardware for the rocker stands.
New valve springs installed and rocker stands mounted.
Piece of Teflon plumbing tape on top of the valve making sure the valve geometry is correct and I’m hitting the center of the stem. Good way to check this because the Teflon tape imprints easily.
Next I installed the a couple rockers and measured for pushrod length at zero lash. Stock pushrods are 7.500” but with the new rockers I came up with 7.650” using my pushrod length checker. Checked 3 to be sure I had the correct length and proceeded to order the new 3/8” pushrods to replace the 5/16”.
New Trick Flow 3/8 0.80” wall thickness single piece pushrods.
Lastly, I installed the pushrods and new rockers, then set the valve lash using the adjusters on the new T&D’s. Valve lash was set to .050 for each valve.
I bought a used meth kit from another Viper member for really cheap. Turned out the harness was all cut up so I needed a new one. Also ended up buying new tubing and check valve, but still managed to save a couple hundred bucks overall.
As purchased. Basically I only ended up using the pump, reservoir, and nozzles.
New tubing and harness.
Installed the pump on the underside of the trunk area behind the passenger fenderwell. This will keep the dust out of the pump but still provide easy routing for the pump to reservoir which is in the trunk.
Pump mounting holes through trunk (under the carpet)
Hole drilled and supply line ran to reservoir with a grommet
Wired the pump power to the battery with a quicktap.
Fuse line, ground, and relay wired into battery area.
Also hooked up the control harness to the pump and mounted the boost control box near the pump. Lastly, hooked up the meth line which will route to the intake.
Next, I ran the wiring harness and meth line through the transmission tunnel and up into the engine bay near the firewall. A pickup gets tapped into one of the injector wires to make the pump progressive with RPM.
The meth won’t turn on until 3 PSI. My boost reference will simply come off of the manifold and hook up to the control box which is part of the harness already which is super convenient.
I will be running dual nozzles about 10” before each throttle body. I have a check valve in place to keep it from backflowing when not in boost. The supply line and check valve are routed under the intake so you won’t be able to see anything when the charge pipe/cooler is installed.
To finish the meth injection, I still need to wire the pump power switch into the interior and mount a dash light to show me when the pump is on.
For now I’ll just leave these wires here
Finally get to the exciting part and mounting the blower.
I bought this kit used as well. Iím pretty OCD when it comes to things not looking new when I install them so I went about fixing that within reason. For the majority of the cast aluminum bracketing, I had it powder-coated wrinkle black to match the valve covers and intake manifold.
The kit as purchased.
Brackets after powder coating.
Installing the revised shock tower mounts to make room for the blower assembly. Had to drill some new holes through the fender walls to add mounting points.
Supercharger bracket mounted.
Test fitting the shock tower brace. It has adjustable end links.
Power steering pump remounted on new supercharger.
Before I put the head unit on I gave her a little scrub. Not too much effort but enough to make a difference.
Also, before I could mount the head unit, I decided to swap pulley sizes. Stock pulley size is 3.5”. The used kit I bought the former owner was running the smallest size possible with a 2.75”. It was on a 522 stroker though so he was only making about 11 pounds of boost.
I am aiming for 12-13 PSI. With that being said, I decided to go up to a 3” pulley to reduce a bit of slip and create less boost. Over 13 PSI on a stock bottom end is when you things start to get risky. I’d rather make 50 less whp this year and keep things a little safer.
Removing 2.75” pulley.
New to Old pulley comparison (new 3” on left)
Now I was able to bolt up the head unit to measure for the belt length. I needed a custom length pulley since I am going with a smaller than stock pulley. Using an 8 rib Gates Fleetrunner HD.
Now ready to run the belt, head unit, and modified upper radiator hose.
Hooked up the oil supply to the head unit.
Next, hooked up the air to water cooler.
Once on I instantly realized I hated the polished look of the cooler so off it came and went to the powder coater to get wrinkle black to match the rest of the engine. From the get go, I was trying to go with a polished/black theme. I think the head unit being the only large polished item will make it stand out more and keep everything else sleek.
To install the headers, I had to remove the heater fan and shunt tank on the passenger side to get them in, but other than that, not too bad of an install since I already had so much of the engine bay removed.
Used high temp RTV on the connections.
Still need to cobble the exhaust together where I deleted the cats.
Now that the headers are on, I could finally put the valve covers back on.
With the new roller rockers with more lift, there is a chance they could hit the internal oil baffles on the inside of the valve covers.
To prevent this, I simply cut the baffle off everywhere but where the catch can outlets are. I also bent it slightly to create clearance. This should keep the majority of oil from being sucked into the catch can.
Valve covers back on. Time to start putting things back together.
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