Supercharged Gen III purchase questions

[Muffzilla]

I'm looking at purchasing a 03 genIII with about 65,000 miles on the clock. From what I have read these cars can be really stout in stock form. I'd hate to buy this car and be stuck with this guys problems. This is a car that I plan on daily driving. My normal daily mileage is about 4-5 miles.

Here is the listing:

Up for sale is my Supercharged Viper. It has 65,000 miles and many of the mods were done by previous owner at 55,000 miles. mechanically great and can be daily driver. it is a lot of fun to drive! It is a great car with a lot of power!! Call or text with any questions.

List of Mods:
*Paxton supercharger tuner kit: (Kit does not use typical paxton external fuel pumps you would see in the upper right part of the engine bay)
*Duel in-tank Bosch 255lph Fuel pumps: (again did not employ the messy add on fuel pumps that come in a standard paxton kit)
*Injector Dynamics 750cc injectors: Tuner / install shop ((Arrow Racing Technology)) would not install without them.
*Kooks Headers 1.75 primaries/ 3" collectors: System still has catalytic converter "bodies" in place in case of visual inspection.
*Arrow Racing Technology ECU tune
*Corsa 3" Cat-Back exhaust: (sounds super nasty, gargles and pops at idle and deep rumble when WOT) also reduces a LOT of cabin heat from the stock set up.
*Fidanza Aluminum Flywheel: Car revs like a sport bike. Much Livelier than the heavy stock flywheel.
*Centerforce clutch: installed at 55K miles
*RPM Level 5 Tremec Transmission: also 55K miles
*MGW Short Throw shifter
*Seat Lowering Kit: lowers driver seat 1" maintains all adjustments.
*Alpine CDE-HD149BT Head unit: high end head unit with Bluetooth
*MGW interior pieces: Shit Knob, satin silver billet aluminum climate control Knobs and cupholder ring (very sought after as they are no longer produced)
*Molded dash pieces professionally painted silver to match exterior of car: (starting to chip some)
*Black powder coating of Factory rims
*Battery tender terminals wired in
*Two (2) Valentine One radar units hard wired into the car
*Tuner with two custom built tunes tied to car
*Car cover
*Upgraded trunk carpet with stitched logo
*Two (2) extra sets (8 tires total) available (used but great shape) Michelin pilot sport cups


Is there anything that stands out or is the mileage something to worry about with the supercharger?

[Scot@Prefix]

The only issue i see is the Gen 3 Vipers didn't have the best connecting rods, and have cast pistons.
At some point they will fail with a supercharger being run hard. As a daily driver and normal driving it might last a long time.

[ViperSRT]

2003 have forged conn rods and larger crank damper fastener. I have almost 40k with Paxton installed.

[Muffzilla]

How many miles overall? My concern is the price is low ($33k). I probably wouldn't have as many worries if it was higher. Get what you pay for kind of thing.

Also, does anyone know of Arrow Racing Technology is a reputable company? Im obviously not well versed in the Viper world.

[Scot@Prefix]

2003 have forged conn rods and larger crank damper fastener. I have almost 40k with Paxton installed.

There are small and large crank bolts for Gen III we have both at the shop, out of various applications and there doesn't seem to be any rhyme or reason how they determined which one would get a large or small crank bolt
The connecting rods are forged but a terrible material, the same strength as any stock connecting rod.
We throw them away all the time even when they are brand new and never been run.
Based on our experience about 620/630 hp range is the max for reliability from the Gen 3 stock rods/pistons.

Reliability depends more on type of usage/abuse versus power level.

[ViperSRT]

Scot check with Dick (or Charlie as Dick wasn’t involved with Gen3 so much). Many changes during Gen3 and they were not random by any means. I would also be more specific when you state terrible material (as a retired chief engineer for engines I tend to be precise with such statements).

[TrackAire]

My personal opinion is when you're buying a used vehicle this old with this many major modifications, you're buying a huge headache. There is no way to know if all the major modifications were done correctly and to the highest quality. Any stock Viper with 65k on it has to be a little suspect unless you personally know the owner(s) and the cars history. Add in all these major mods and changes and you'll be chasing issues forever.

When was the Paxton installed? By who? Is there a dyno print out showing air fuel mixtures?....dyno horsepower?....when was this car last on the dyno to verify that it is putting out the power it is rated at with the blower? When was the last time the Paxton was rebuilt, if ever?

Any major issue with the engine/trans/rear end and you'll end up with a huge money pit. Put aside $15k-$20k just in case it is needed in the first 3 months of ownership. If it doesn't have issues, then you got a good buy and have some extra money sitting to play with.

At least have the car gone through by a Viper expert to insure that everything is working as it should be. If you're going to buy this car, post up the location and somebody here will be able to recommend somebody near the car for a thorough PDI. Spending a little now can save you a bunch later.

Best of luck with whatever direction you go.

[Muffzilla]

My personal opinion is when you're buying a used vehicle this old with this many major modifications, you're buying a huge headache. There is no way to know if all the major modifications were done correctly and to the highest quality. Any stock Viper with 65k on it has to be a little suspect unless you personally know the owner(s) and the cars history. Add in all these major mods and changes and you'll be chasing issues forever.

When was the Paxton installed? By who? Is there a dyno print out showing air fuel mixtures?....dyno horsepower?....when was this car last on the dyno to verify that it is putting out the power it is rated at with the blower? When was the last time the Paxton was rebuilt, if ever?

Any major issue with the engine/trans/rear end and you'll end up with a huge money pit. Put aside $15k-$20k just in case it is needed in the first 3 months of ownership. If it doesn't have issues, then you got a good buy and have some extra money sitting to play with.

At least have the car gone through by a Viper expert to insure that everything is working as it should be. If you're going to buy this car, post up the location and somebody here will be able to recommend somebody near the car for a thorough PDI. Spending a little now can save you a bunch later.

Best of luck with whatever direction you go.

From my short research I have found that it all comes down to the tune, as with most cars. I spoke with the owner and he is unsure of the power figures but estimates around 650. I'm having doubts that it was properly tuned so I'll have to steer clear of this one for now.

[ViperSRT]

Something is strange. In the info you quoted it states Arrow Racing ECU Tune (and based on the fuel system information it MUST have a unique tune to match the fuel system and injectors). Then you state no tune information. But most strange is the representative from Prefix, which owns what was called Arrow Racing, came on and fed negative information in general but nothing about the tune. Strange indeed.

[plumcrazy]

im an idiot with a severe lack of coffee this am. thread moved back to where it belongs

[Muffzilla]

Something is strange. In the info you quoted it states Arrow Racing ECU Tune (and based on the fuel system information it MUST have a unique tune to match the fuel system and injectors). Then you state no tune information. But most strange is the representative from Prefix, which owns what was called Arrow Racing, came on and fed negative information in general but nothing about the tune. Strange indeed.

When pressed for dyno sheets the owner said that they had not put it on a dyno and the HP numbers were an estimate. I don't know if the tune is from street tuning, dyno tuning or mail-in tuning. He knows a lot of very specific stuff from the Paxton install but very little about the tuning or exact numbers.

It does feel strange that the previous owner installed the Paxton at 55K then sometime between 55k & 65K this guy bought it. I don't see why someone would spend upwards of $15k just to sell the car and then resold so quickly.

[TrackAire]

When pressed for dyno sheets the owner said that they had not put it on a dyno and the HP numbers were an estimate. I don't know if the tune is from street tuning, dyno tuning or mail-in tuning. He knows a lot of very specific stuff from the Paxton install but very little about the tuning or exact numbers.

It does feel strange that the previous owner installed the Paxton at 55K then sometime between 55k & 65K this guy bought it. I don't see why someone would spend upwards of $15k just to sell the car and then resold so quickly.

This is very common as certain upgrades (when not done correctly) turn the car into a piece of crap and that owner now dumps it onto the next guy. Look at all the Lamborghini Gallardo's that have been twin turbo'd at costs of $80k to $100k plus and the owners dump them less than a year later. For a Gen III car, adding approximately another 200 to 250 horsepower never equates to reliability when cutting corners. Can it be done, absolutely if the the person doing it is willing to spend the money and do it correctly. 90% of this forced induction builds are not done correctly and become a money pit for the owner who then dumps the car on to the next guy. You never hear of the problems because owners keep their mouth shut as to not screw themselves when trying to unload the car onto the next sucker.

Take your time, you'll find the right car for you.

[Steve-Indy]

Agree with TrackAire well written comments !!

Muffzilla, there are a lot of great cars out there...many of which are not listed in the public domain, but are/could be for sale. Members in your area are usually aware of these cars and their history. In my 20+ years of "playing Viper" I have seen dozens of these private sales completed in our area alone...with BOTH seller and buyer being happy afterwards. Take your time...and, I would suggest that you shop value before cost. Good luck with your hunt !!

[Scot@Prefix]

Scot check with Dick (or Charlie as Dick wasn’t involved with Gen3 so much). Many changes during Gen3 and they were not random by any means. I would also be more specific when you state terrible material (as a retired chief engineer for engines I tend to be precise with such statements).

I agree terrible material is a general statement, forged cast iron connecting rods are developed for the stock power levels. I don't know of any manufacture that builds a stock production part that was purposely built to handle more power or be more durable that the factory hp rating.

Something is strange. In the info you quoted it states Arrow Racing ECU Tune (and based on the fuel system information it MUST have a unique tune to match the fuel system and injectors). Then you state no tune information. But most strange is the representative from Prefix, which owns what was called Arrow Racing, came on and fed negative information in general but nothing about the tune. Strange indeed.

I agree it would have to have a "tune" with larger injectors, typically Paxton offers a tune or boost referenced FMU to provide the additional fuel.
ViperSRT how is your Paxton setup for fuel enrichment under boost?


The other thing i noticed it says "it has tuner with two custom tunes tied to the car" The arrow controller does not allow for two tunes, on a viper we only use the factory computer and modify the programming. Definitely some conflicting information.

[ViperSRT]

The minimum specification I am aware of is a 1.3 safety factor is normally applied to conn rods for the worst case planned application. It is not hp related, but rather max compressive and tensile force related. These occur at max BMEP (i.e. torque) and peak over speed, respectively. Damage calculations take into account loading frequencies. All told a mechanical part like a conn rod can take about a 50% increase in compressive loads without much concern, unless placed in extreme situations. Tensile loads will not increase unless the FSO is increased, heavier pistons installed, or missed shifts occur (should be low frequency so ultimate tensile strength related rather than fatigue). Poor calibration that leads to heavy detonation can overcome that quickly, which may be why you see it. Failure modes look different if you know what you are looking for. I know - too much information. But to dispel your comment about design strength. Note also you can have powdered metal, powdered metal forged, and forged steel rods (and billet but that would be outside most OEM realms). Forged cast iron rods do not exist that I am aware of. Differences are not only material but also grain structure, which is very important in rods.

As for mine I have the basic system from Paxton with unique calibration. It is very conservative for both f/a and spark advance.

[Gen3CoupeTX]

I bought and still own my Paxton '06 Coupe. I was leery since I didn't know the full history. But you can tell when they are done right. I look for extras such as cooling system upgrades, no corners cut, the things folks doing things on the cheap don't bother with.

Mine had 10K on it last Spring when I bought it from BJM / VE. I've put 1K trouble-free miles on it, smiling like an idiot the whole time! I've built and bought several forced induction cars over the years, and my only concern with yours would be the mileage. Sounds a fun ride though!

[commandomatt]

Important is who has done the install. Everyone thinks they are a good mechanic but this is far from the truth. Like anything else, repetition and experience will determine how well these types of install will work over time.

While the Paxton kit has been installed in hundreds of Vipers, that doesn't mean that you can assume that it has been done properly

My Paxton was installed by Woodhouse and I think that lends value to the car as opposed to a system that was installed by some 'Joe' that may or may not know what he's doing

There are countless of threads with guys doing first time projects and are asking about what basic tools and equipment to use to get it done. These are not the type of cars that you practice on and would not be a car that I would consider buying

[Jfitz6]

Hello all I actually purchased that viper muffzilla was looking at (not for 33k) but i ended up tracking down owner that had the mods done and was very helpful of what had been done and by who. I agree the guy selling wasn't super knowledgeable about the car and I almost passed up too. but I'm glad you passed on it cause I'm having a blast with it, taking a road trip this weekend again! Hope you ended up finding one yourself!

[Viper4Life]

Hello all I actually purchased that viper muffzilla was looking at (not for 33k) but i ended up tracking down owner that had the mods done and was very helpful of what had been done and by who. I agree the guy selling wasn't super knowledgeable about the car and I almost passed up too. but I'm glad you passed on it cause I'm having a blast with it, taking a road trip this weekend again! Hope you ended up finding one yourself!

Congrats on that working out for ya! Got any pics to post?

[Gen3CoupeTX]

Jfitz, congrats! I've found very few things that can generate the smiles that boost can. Enjoy, MM

[Fatman2006]

Congrats on the car, being supercharged and what not, you're going to need a lot of oatmeal!!