Whats the maximum amount of "Naturally Aspirated" RWHP/RWTQ on a Viper?

[Yellow Fever]

Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

I see a lot of crazy HP #'s from the Supercharged viper owners..But I'm not that familiar with what kind of #'s can be acheived with a solid NA set up ?

Is 700 RWHP doable ?

Cheers
Jeff

 

[Cudaman]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

The 2 fastest Naturally Aspirated Viper( that I know of) was George Bryce ran first a 10.25 ( Lingenfelter Viper)and then SW 10.0? ( RSI?)at V-10 Nationals at Bowling Green.

Cudaman

 

[Chuck 98 RT/10]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Is 700 RWHP doable ?

"Streetable?" Dunno. The Team Oreca Viper motors built by Caldwell were putting down those numbers.

 

[Martin D]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Great question.

On Stock internals (488) running pump gas - 600rwhp is about the best you can do....unless you want to go radical with Intake, dry sump, and motec, etc...

The highest number I have heard of is 700rwhp that car is running race gas, solid lift cam, and stroked (510).

So, it depends on what you want to do, and how much you want to spend.

Regards,

 

[Yellow Fever]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Martin , I see that your having a stroker built ..Who's building the stroker for you ?

What are your expectations (RWHP/RWTQ)?

Thanks !

Jeff

 

[JGK95]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Great question.

On Stock internals (488) running pump gas - 600rwhp is about the best you can do....unless you want to go radical with Intake, dry sump, and motec, etc...

The highest number I have heard of is 700rwhp that car is running race gas, solid lift cam, and stroked (510).

So, it depends on what you want to do, and how much you want to spend.

Regards,

Martin,

Great Info! and a great question! Can you please give more info on where I can read up? I'm planning on setting up a GTS in the very same manner. Planning is everything.

Thanks,

Jay K.

 

[Martin D]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Jeff,

For my stroker - the 510, I had the short block assembled by Hennesse y. We used coated bearings, JE Pistons, and Manley Pro Rods. Compression will be 11:1

I am putting it all together with McIntosh Performance here in Atlanta.

I am expecting about 625 at the tires. But here is the deal....I could have upgraded my heads to CNC OR gone with Gen 3 heads...Either would give a significant gain over my current heads that are hand ported. Also, I could have gone 12:1 or higher and used Race gas. I will probably eventually upgrade the heads and do a solid lift cam. That should get me close to 700 at the wheels.

Jay - As for threads on Strokers.....Do a search on Strokers..Or, you can send me an email, and I will be glad to give you my opinion on various options.

Regards.

 

[Yellow Fever]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Thanks for the info Martin !
I'm curious why you chose the stroker route instead of being blown ?
(No pun intended )

Do you feel that an SC set up would be less reliable ?

Cheers
Jeff

 

[LTHL VPR]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Great question....When I consulted for APEX on stroker packages about a year and a half ago, we experimented solely on naturally aspirated setups. We found some very interesting things.

With wild cams and head combos we could get some really good 'bragging rights' peak numbers, but the mid range suffered terribly. I think too many people get caught up in the peak numbers and don't stop to think that they may only see that power for a blink of the eye... Personally, I would take an extra 25rwhp at 4500 rpms anyday over 25rwhp at 5900 rpms.

In the end, the best overall power and torque across the rpm range was seen with heads that were not 'hog ported'. What I am saying is that less cfm @ .500 lift made more power across the rpm range, probably due to the intake restrictions and the higher cfm we could get at lower lift. I found this very interesting. A great example of this type of effect was 'noted' in a recent Car and Driver article about the [******] 600+hp SRT package. I think they said something like the car was a few seconds slower than the stock SRT when accelerating in the same gear with with the heads and cam mods at low-mid rpms. Again, low-mid range power they were talking about.

In addition, properly matching the cam with the head flow and intake proved to be a difficult task but well worth it (we saw another 50+rwhp with a proper match). When we completed the LETHAL 650 package I know I got a ton of e-mails from people trying to figure out how we made so much torque and power from 2500-4000 rpms.

Anyway, I don't know what the most hp and torque is to date, but keep in mind that drivability and type of gas (pump/race) can play a major role in this.
After several cam, head, and exahust changes, my 01 ACR with the LETHAL 750 package pulled 671rwhp and 704 rwtq. This car is very drivable and does not require race gas. The compression ratio is under 10.5:1 (I am sure it would make noticably more power with higher compression).Certainly with a more aggressive cam, more head porting, or race gas you should be able to reach 700rwhp, but it will probably cost you some valuable power in the low-mid range which may be sorely missed.

Here are my latest numbers. The engine has 1200 miles on it...still breaking it in...

3400 rpms...420 rwhp, 655 rwtq
3800 rpms...490 rwhp, 675 rwtq
4200 rpms...560 rwhp, 700 rwtq
4600 rpms...600 rwhp, 690 rwtq
5000 rpms...630 rwhp, 670 rwtq
5400 rpms...650 rwhp, 630 rwtq
5600 rpms...670 rwhp, 610 rwtq
5800 rpms...640 rwhp, 580 rwtq

* From 3200 rpms to 5700 rpms the car never makes less than 600rwtq!
* Interestingly, I think because the power is sooo smooth and the torque is flat, my car does not break traction under WOT in 2nd gear once the tires are warm, so it hooks up really well.

Hope this helps! If you are really trying to get 700rwhp, it is certainly within reach!
-Wayne

 

[Maverick The Electrician]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

If you go the motor route, you may want to do some research. I have seen stroker motor cars make less RWHP than heads and cam cars. A good heads and cam car can make well over 550-580 RWHP. I have seen strong stroker motors at 630-650 range. SW's car in a race set up made almost 700 RWHP. I am currently doing a stroker motor in mine, will let you know how it does, but the RWHP was guaranteed.

 

[LTHL VPR]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Good point, Mav. I too have seen a car with ported/polished heads on it that made less power than a Viper with just an exhaust upgrade. Scary!!

Make sure the work is done by someone who knows what they are doing and what your objectives are.
-W

 

[JGK95]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Jeff,

For my stroker - the 510, I had the short block assembled by Hennesse y. We used coated bearings, JE Pistons, and Manley Pro Rods. Compression will be 11:1

I am putting it all together with McIntosh Performance here in Atlanta.

I am expecting about 625 at the tires. But here is the deal....I could have upgraded my heads to CNC OR gone with Gen 3 heads...Either would give a significant gain over my current heads that are hand ported. Also, I could have gone 12:1 or higher and used Race gas. I will probably eventually upgrade the heads and do a solid lift cam. That should get me close to 700 at the wheels.

Jay - As for threads on Strokers.....Do a search on Strokers..Or, you can send me an email, and I will be glad to give you my opinion on various options.

Regards.

Martin,

I will be doing a search on stroker motors awa adding this thread to one of my all time favorites list. I truly understand the separation of DynoQueens now from this thread. The most important factor that I've come to realize is getting the most torque at the earliest RPMs. 600 rwtq at 3200 WOW What caught my attention was that you stated the hand ported heads were less of a performer than the Gen III heads. Please explain, is it really that radical? With so many good heads makers out there, I feel overwhelmed in my search.

Thanks for your valued info. As I get closer to setting up the car we in fact WILL be speaking.

Thank you,

Jay K.

 

[Yellow Fever]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Thanks for the feedback guys ! Wayne, you have mail

Cheers

Jeff

 

[LTHL VPR]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

BLUTHINDER-
You have mail....

JGK95- Yes, having 600 rwtq at 3200 rpms is great!! I think that's why Car and Driver magazine called my car the 'All time King of Throttle Response'. Mine stroker package is NOT a solid lift; wanted to keep things more simple. Car makes peak power at around 5600 rpms and peak torque at 4300 rpms. Tons of torque everywhere. Nothing's more pleasing than pulling on a 911 when I am in 5th and 6th gear and they are in 3rd!! I try to make it a little more challenging this way.

Regards,
Wayne

 

[Torquemonster]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

This is a good thread!

Wayne's LETHAL750 motor is without doubt one of the finest motor only combos for the street on hyd roller. The figures speak for themselves - and as Wayne said, having power in the mid range is key on the street. A fat power curve will feel a lot stronger on the street than a peaky one even though a very high peak power may win on the strip if the gearing is matched to keep it in the peak range.

In street driving - to get the best out of a peaky engine you must always be in the right gear at the right rpm or you'll get holeshot everytime. Think - driving a ricer. Who wants their Viper to be like a ricer?

My definition of fat vs peaky in this setting is different than for a milder engine. In this power level - a fat power curve is one that pulls harder than stock from 3000rpm to 6000+. A peaky one will pull harder than stock from 4000+. That 1000rpm makes all the difference.

There is significant gains to be had by going to solid roller cam. The faster ramps will make it possible to gain power everywhere, or build even more top end without losing excess bottom end. The trade off is the need for stiffer valve springs and routine lash adjustments.

The Gen. 3 heads - properly prepared - will allow a 500 cube Viper engine to be built to possibly 1000hp (850rwhp) on motor alone. But it would be all out drag race and require many fabricated parts - like custom throttle bodies/intakes etc. The stock bottom end would also be thrown away and replaced with longer rods, shorter pistons and stronger crank.

For acceptable street use retaining some bottom end - I'd expect around 750rwhp on a solid roller cam engine with top prepared Gen 3 heads to be around the limit - and that would require 500 cubes+. These are rough ballparks figures only and do not take into account the fact the intake or something else may be a bottleneck to get past a certain figure. A higher flow intake I think would be required.

As mentioned - not all heads are prepared equally - even CNC heads are only as good as the template. CFM is only one variable. Velocity is as important and good velocity at low lifts is more important for a street engine than peak CFM at high lift. Not many people talk about the velocity of their heads because they are under pressure to put out big CFM numbers to impress everyone - but the real head gurus know where it is at - and peak CFM is not it.

As for strokers - more is not always better. When rod stroke ratios drop below 1.5 don't expect long life at 6000rpm. Monster pro stock engines tolerate poor rod stroke ratios only because they are engineered to compensate for the shocking loads and stresses - they'd not last a weekend on the street. They also use the longest rod that can physically fit.

For the Viper - rod ratios in the low to mid 1.4's is a low rpm engine - don't think you can rpm it like a stock one forever without very good gear (incl. after market rods) and expect higher bore and ring wear as the longer stroke tries to push the piston thru the sides of the bore - esp. as piston speeds reach the stratisphere. A short rod ratio moves the pistons much faster than a longer rod ratio. At low speed this fills the cylinder quicker and helps torque, but as rpms rise it becomes a problem as there is less time to fill to cylinder and the piston speed reaches a point that it will at some point fail without the strongest of hardware used.

The old Mopar 440 uses 1.8 rod stroke ratio - they lost a little torque to a short ratio motor like a 454 Chev at low rpms - idle to 3000 - but after that it is good bye Chevy. A well built 440 will make more torque and hp than any equivalent spec 454 and will rpm at 6000+ all day on 2 bolt mains.

A well built 440 will peak torque at 4000 but will still be strong off idle up. That makes them a great engine for hot street work. The equivalent built 454 will peak torque much lower in the rpm but will not be as happy at WOT where you will stay above 4000. Result - at partial throttle the 454 will feel slightly stronger - but bang down a cog and nail it at 3500 and the Chev will be blown away.

A stock Viper will dork any 700rwhp motor only from idle to 2500rpm - that is the trade off - but after that is where it is at.

Lesson: A big stroker makes more power everywhere at lower rpms - but if you want to go for it - keeping rod ratios to a sensible limit will be more important than how big the engine is. Also - how much bottom end are you willing to lose?

 

[Yellow Fever]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Thanks for the informative reply Barry ! It seems like most of the aggressive Dyno#'s are coming from guys with SC set ups..Given the fact that a quality SuperCharger pkg will run approx $25K -$30K ( Forged interals, head/cam work , Paxton or Vortech Blower ,Headers etc..)

Based off this information a Stroker pkg could get in the same Dyno range with a much more linear power curve..Why would anybody choose an SC pkg over a Bad ass NA set up ? (price being equal)

I would think that a NA motor would be a more reliable set up...and as you pointed out it would have much better Torque curve.

I'm trying figure out if I should go with a Supercharger or NA set up

CHeers

Jeff

 

[Joseph Dell]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

Although I'm a SC guy, let me put on my old stroker hat from years past...

Stroker motors _traditionally_ were less reliable than SC motors because the internal parts used to wear out quicker. And in line with what Torquemonster said, extra-long valve lengths or strokes that were too long tended to cause premature engine failure. Example: Talk to anyone rebuilding a ford 302 and ask them about stroking it to somewhere between 306 and 347... there are 347 kits out there, but they just didn't last. Most folks would choose a 306 or something _near_ that rather than going to the max they could.

That being said, the SC cars don't put any additional wear and tear on the motor under normal driving conditions... it is while under boost that they push the air (and correctly the fuel) into the motor.

Many a SC car have run 750-800hp at the tires w/o modifying heads or cam. So you can maintain your drivability w/o having to take the motor out to rebuild the internals.

As for pricing, most of the SC tuners prices fall between 10k and 20k for the get-you-started-and-make-you-happy types of set ups.

Finally, if you look at what production line cars are being rigged up with, many come from the factory with superchargers or turbos. Why? Because they are reliable.

Not to say that a stroker isn't reliable. I'm sure they can be built as such. But for my daily driving, I like knowing that if I mash the go-fast pedal, I get 700hp at 3500rpm. But if I don't mash the pedal, the car still drives like a normal viper.

Just my .02...

JD

 

[Yellow Fever]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

JD, All valid points ..Thanks for your input !!

Cheers

Jeff

 

[Torquemonster]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

I concur with Joseph - the all motor is great for circuit racing where weight is a big issue and extra power adders can't be put to the ground anyway.

A high compression all motor will have faster throttle response than boost, but we're splitting hairs - a well set up boosted Viper will not be sluggish at the prod of the throttle!

A well built boosted engine will make more power and torque everywhere.

At equivalent hp levels both will suffer heat problems at WOT and slow speed work - but the advantage goes to all motor which has no big front intercooler to reduce the radiator efficiency. This only impacts tight circuit type work - esp. on a hot day.

The only other issue with SC is belts - they will wear over time, but can be changed by yourself on the better setups. Turbos don't have that problem. Both SC and Turbos should run for years - just keep the oil clean.

Do not think that because an all motor 700rwhp Viper ran almost 10 flat that it will be quicker from a roll or feel as powerful as the SC cars running low 10's that make 850rwhp. The difference seat of pants will be huge - it is just the boosted cars are not getting it to the ground - try a roll on from 50mph and the 850rwhp boosted car will pull the all motor car with ease. The boosted car will also have far greater bottom end and be closer to stock to drive as Jospeh said.

It comes down to how much you can use and what you prefer. It'd be fun to have both - but in the end - the boosted car will be the one you grab the keys for most But then, on a balmy sunny afternoon in the mountains - along a good windy road - the all motor car with good compression will be a blast whereas the boosted car will be white knuckle trying to keep the boost down to managable levels.

 

[JGK95]

Re: Whats the maximum amount of \"Naturally Aspirated\" RWHP/RWTQ on a Viper?

I think somewhere on this board someone said " You'll run outta Ba!!s before you run outta speed" LOL! Forgot who that was... This is a Great thread going, I've read all sides and definitely see myself going the NA route for road racing like the Viper CC motor (Motec and other ideas) with the exception of going to Caldwell. I'd have to knock off a brinks truck first!

Jay K.