Rev Limitations

[SpinMonster]

I would first like to say hi to all the members as I am new to the forum and I'm just doing some comparitive investigating on transitioning from a heavily modified corvette to a viper.

I have many questions about modding a 1999 rt-10 and will post them as I have time.

My first question has to do with the rpm rev limitations as I noted the engine is red lining relatively low in the 5500-6000 rpm range. What are the components that cause this rev limit....valve springs-lifter type or brand-engine balance-rocker arms? What fixes (specific parts/brands) are available to allow the use of a higher rev limit---near 7000?

 

[Russ M]

Viper=Low rev's

Forget about trying to make it rev out higher no point, you can make a load more power if you want at low RPM's.

 

[joe117]

You didn't ask about $$$ but just in case you don't know I'll tell you.

It will cost quite a bit more to mod your Viper. Limited components available and very expensive.

 

[Fishtail]

I would first like to say hi to all the members as I am new to the forum and I'm just doing some comparitive investigating on transitioning from a heavily modified corvette to a viper.

I have many questions about modding a 1999 rt-10 and will post them as I have time.

My first question has to do with the rpm rev limitations as I noted the engine is red lining relatively low in the 5500-6000 rpm range. What are the components that cause this rev limit....valve springs-lifter type or brand-engine balance-rocker arms? What fixes (specific parts/brands) are available to allow the use of a higher rev limit---near 7000?

I believe part of it is oiling too. I hear the oil pumps in the engines are not that good at over rev.

-Lou

 

[SpinMonster]

Amazing: You ask a AND give exact examples of what you are looking for as far as types of answers and you still get: you can't do it and it cost too much as compared to a corvette. (so far regearing costs less than a corvette)

It is an engine and I do my own work. there must be mechanical reasons why it can't rev to 10k like an engine with the same stroke. So lets try it a new way:

1-roller rockers: available?
2-dual valvesprings: available?
3-external oil pump: definitely available
4-upgraded lifters/solid roller? available?
5-has anyone successfully run this engine near 7k?

As far as reasoning, a person interested in drag racing wants a higher rev limit so that regearing the car with say 4.10's along with drag radials or slicks gives a much better 0-60 and 1/4 mile times when you have the ability to cross the traps at 7k in 4th gear and not have to shift to second going to 60.

Thank you for responding and trying to help but if you dont know what causes the rev limit please do not tell me it can't be done or it is too expensive.

 

[RedGTS]

Thank you for responding and trying to help but if you dont know what causes the rev limit please do not tell me it can't be done or it is too expensive.

No problem. There are a couple of reasons no Viper drag racers, including those who have unlimited funds for upgrades and run 9's, go your route, and neither of them is because it can't be done or because it's too expensive. It's because it doesn't make any sense.

 

[AG98RT10]

If all you want to do is run 1/4 miles, the Viper is a waste of time. Sure, there are guys here running nines in snakes, but the cost and effort to do so is high, and you end up with an expensive vehicle that is little better at road racing than before.
The Vette is also compromised for 1/4 mile running, since it's also more of a road racer design. People say if you want 1/4 mile times, better to just take an F body and mod the hell out of it - less money and better results.

 

[joe117]

Thanks for setting me straight on giving you info that you didn't need or ask for, I'll try to improve.

But hey, if you want to see some discussions on Viper V10 at 7000 rpm, you can do a search on the words "7000 rpm".
Here's a link to the results. http://vca2.viperclub.org/forums/dosearch.php

Seems like the problems are more than just replacing valve train components with better ones.

Oiling, piston fly cutting and lower end strength seem to be some of the problems.

Also, and I know you didn't ask, @ 7000rpm the 4.11 rear with 27" tires, will only get you 51mph in 1st gear. It will only get you 137mph in 4th gear.

There are some guys on the board that are running faster than that in their Vipers. I don't know for sure but I don't think they are turning 7k rpm or using 4.11 gears.

The big time road racing Vipers do turn up to 7k rpm. Check with those guys.

 

[Bullet488]

I can offer some insight into the limitations that might explain the lack of information. Unlike the LS1-LS6-ZR1, I have never seen a viper motor continue to make power over 6000rpm. This includes strokers, forced induction and N20. I've seen ported heads, ported GTSr heads, big valves, extruded intake manifolds, hand ported intakes, big tube headers, etc.. Regardless of modification made to increase flow the engine does not like to make power over 6k. (All my experience is in drag racing so I'm not sure what the road racers are doing) The GTSr race cars with their dry sump oiling and revised intakes may be the exception, but that is FAR removed from what most are willing or able to do.

That being said.. There are several types of roller rockers available (arrow, mopar, T&D) and I know that a few have tried solid roller cams. I've also seen some oiling modifications and you have valvespring options. The most important realization is that you must change your strategy and work with the characteristics of the viper's V-10.

FYI, in a 542ci bulletproof stroker motor, we go through the traps at around 6400rpms. Although the engine could likely handle it, ANY higher would be a COMPLETE waste of time and would necessitate a gear swap. With a taller tire or a little less gear, we would run faster. Keep in mind that with the commonly available gears (3.08, 3.31, 3.45) you trap anywhere from 140-150+ at ~6000 rpm in 4th gear. The low end torque of this motor DOES NOT require a steeper gear to get the 60ft or 1/8th mile you need to run a number.

Hope this helps and good luck with the viper.
Scott W

 

[Cris]

My first question has to do with the rpm rev limitations as I noted the engine is red lining relatively low in the 5500-6000 rpm range. What are the components that cause this rev limit....valve springs-lifter type or brand-engine balance-rocker arms? What fixes (specific parts/brands) are available to allow the use of a higher rev limit---near 7000?

The 1999 red lines at 6200 and hits fuel shutoff at 6250, I believe. Not 5500 to 6000.

As indicated above the GTS-R was capable of higher engine speeds. Through Mopar you could at one time buy many of the unique components that would help attain that goal. That is an expensive solution. Titanium rods, polished crankshafts, dry sumps, short runner intakes, extrememely long duration camshafts, light weight pistons, roller rockers, higher load valve springs, etc can all help you get there. But the question really is why. Unless you have a limit imposed on you by an organization (such as a restrictor plate like the GTS-R required) let the cubes in the Viper work for you. They don't hand out awards for red line. Results are what is important.

 

[SpinMonster]

As for why: my experience with my 426 hemi is such: I have 725rwhp on a solid roller motor that turns 9500 at the traps. No off the shelf cam makes power up that high. That translates into higher 1/4 mph speeds and with 6.13's in the rear, an 825rwtq vehicle CAN hook with higher gear ratios. Limiting rpm and running 3.07's is not the answer. I respect the v-10 but the laws of physics dont include a separate chapter just for this engine.

It is also my observation that 9sec vipers are as easy (and cheap) as a top end and a 200 shot.....9.72 if the ad was not a lie.

I wasn't trying to start an argument but as an engine builder not familiar with this motor, I am surprised that there was only one post that showed any useful info. Any cam grind can be had for the viper and an aftermarket computer/engine management system would be needed but what was the point in not just saying the valve springs are the weak link (valve float) or the hyd lifters can handle any more spring pressure....only one post to tell me such things. I dont need anyone to build the motor for me. Just looking for the right parts combination to start with.

A fully balanced short block with forged internals (still dont know what crank or rod bearings to use....fed mogul???) should be able to wind very high 8-10k on ANY motor. That combined with a custom grind cam on a narrow LSA will make power up high as any engine will. Head flow is the next issue.... gtsr heads are 6k....add 3k for a balanced short block /forged diamond custom pistons and rods.....stock crank....add computer 2400, headers 1600, air cleaners 300, exhaust 1500, rocker arms1100, dry sump system (COST?) and a 200 shot (have it) and I come up with a number far under 20k which is a lot less then I had into my vette. I'll decide what is too expensive or 'worth it'.

the tach has warnings on it as you get to 5500....why?...just wondering if anyone had any input I wasn't having an attitude....guess it came off that way...sorry but DOES ANYONE KNOW THE FACTORS THAT LIMIT THIS ENGINE'S ABILITY TO REV HIGHER---EVEN TO JUST NEAR 7K....it isnt in the lower end....and oiling can be corrected.

 

[SpinMonster]

If all you want to do is run 1/4 miles, the Viper is a waste of time.

That is an opinion. I saw a viper canibalized for it's internals and dashboard to make a v-10 powered challenger at the NY car show....that is a waste of time or is it simply a project that you're not interested in?

I like the viper it is rare and looks good to me...juuuuust a bit surprised that the dodge flagship can't keep up with a vette that has 10k into the motor so I plan to fix that, for me....and I have no plans of racing. I also never went parachuting, windsailing, or golfing....all of which I would think of as a waste of time.....just illustrating a point.

From the heart though; thanks for the input.

 

[joe117]

So what is your question? You have an answer for every point that anyone has brought up. It's just an engine, if any part of it cant do what you want, fix it, make it stronger, lighter, better.

If you have no limits as far as money is concerned.
You know as well as anyone that any engine can be made to do anything.

So there you go, if you want to make the V10 go to 10k rpm, just go out and do it. You know how and you have the money.

I don't think you really want to mod a V10 at all.
I think you just want to ask questions about why the V10 can't make power like a modded Chevy V8.

This is kind of a tip off,
"a bit surprised that the dodge flagship can't keep up with a vette that has 10k into the motor"

Did you really come here to ask questions?
I don't think so.

 

[SpinMonster]

By the way....thanks to bullet488 for the informative post

 

[SpinMonster]

So what is your question? You have an answer for every point that anyone has brought up.

Well when people tell me I have to flycut pistons to get a motor to rev, yeah I will have a response to that kind of input....if valvefloat causes the valve to hit them springs with more tension fix it.

I think my question was answered by a few people that refrained from telling me things that have no mechanical info.

TO ANSWER YOUR MOST RECENT QUESTION: what things can I do to increase the rev potential of this engine?
you gave a good link but didnt stop there, maybe you should have. As for my statement on the differences in modding vettes and vipers:get over it, I didnt mean anything bad.

 

[Cris]

You have shown a crappy attitude and received about what you should have expected.

On a more informative note the V-10 is based on the 360 / 5.9L Chrysler V8. Outside of tuning effects and dynamics, which would be different, I would think that you could base changes on the 5.9L which has a lot more tuner parts available.

Note also high speed dynamics of this engine will be different based on the odd fire aspect. I would not make the assumnption that things that work on a v8 automatically will work on a v10. The faster you spin it the more important the dynamics. I am not aware of any tuner that has made a high speed version of this engine. There may be reasons why. The rest of the world may not be as smart as you but they are not idiots.

 

[DChan415]

PISTON SPEED

 

[utahviper]

If you want a high reving motor call caldwell in california or fat albert motorsports in arizona, they do it all the time.

As far as I understand it is a oiling problem(fixed with a dry sump system $5000-6000, Fat albert or west coast viper) and a solid roller cam( caldwell or fat albert). There are some rotating assembly upgrades: (Rods $1100-3000, pistons $1000-1500, billet mains and studs $?, new rod bearings $?, cryoing the crank, and a bunch of machine work on the block $1500-3000 depending on who) I would guess that you would have $10k in the bottom of the motor, without the dry sump system but including the cam, to be able to run 7-7.5k rpm. Then you have the upper end of the motor to deal with, intake( upto $10k), computer $1000-3000, mopar heads with porting and bigger valves $5k for heads and $4k for porting and valves, T&D's $1100, headers and exhaust $2500-3000,add another $3k for miscellaneous and you are probably there.

To sum it up, 10k for the bottom of the motor, 5k for dry sump, 15-20k on top end. Total approximate $30-35k and I think it is a pretty good guess. Caldwell and fat albert do motors for around 35-50k, not including exhaust or computer. BTW, you can go crazy with a stroker billet crank $6-7k.

I know you do all your own work but are you a machinist as well? If so then you can take the labor out of the equation.

I have a pretty good handle on the prices because I just rebuilt my bottom end and assembled the motor myself(with the help of some friends).

 

[RedEnuf93]

It is possible to make a 4-****** to spin 11.000rpm...
It is possible to make a V-8 to spin 9500rpm...
It is possible to make a V-10 to spin 9000rpm...
It is possible to make a Harley motor for drag racing...

What is the reason you are intrested of making Chicken Salad out of Chicken [******]?

Buy a $8000 Nova and you will go faster for half the effort and time (and I am not even referring to available funds yet)....

I just dont see the logic here. Viper motor in not meant to be a drag race motor, it is a motor made for low end torque. I see its suitability in canyon carving and at the track (left and right turns)

Why make a Massey-Ferguson a F-1?

However if you are a pioneer on the field and are willing not to take NO for an answer, I will lift my hat for you. I would like to be proven wrong, since I love the Viper.

I would say go for it, let me know later that I was wrong...

 

[SpinMonster]

As per Lingenfelter(thanks for the e-mail): the rev limitations are from the valvetrain: stock springs, lifters, rocker arms, and retainers; the motor revs fine to 7k with that replaced and power output at those rpm's is had with custom cam grinds available from Chris at comp cams....thanks for all the input.

Once again (with my crappy attitude) if you dont know the answer to a TECH question refrain from offering opinions as to why something is a waste of time, too expensive, or that it doesn't make sense to you that someone wants to do it.

Posting of opinions doesn't belong in this thread. Post it in the general discussions area where people care about such fluff.

All this because the tach is marked at 5500 and I wanted to know why....THIS WAS A TECH THREAD FOR INCREASING REV ABILITY.

For those that offered any tech info..thank you and I will not be checking back on this thread since we now have an answer.

 

[Joel]

Such arrogance

 

[9 seconds]

Such arrogance

And ignorance.

 

[GR8_ASP]

Okay, I see I do not have enough technical knowledge for this or related topics so I will keep my keyboard silent. BTW once you find a way to spin that V10 to 10,000 rpm let us know.

It is an engine and I do my own work. there must be mechanical reasons why it can't rev to 10k like an engine with the same stroke.

 

[joe117]

So here he is, doing SERIOUS RESEARCH. DO NOT DISTURB.

Yes, he's a ****.

 

[Daniel Cragin/DC Performance Inc]

The Viper engine can be made to rev much higher, but it is very expensive and the power curve is really not useable for street applications. The higher piston speeds and valve spring pressures will limit the life of the engine. If you really want to build an engine like this, the GTSR race block is the way to go (smaller crank journals). Production connecting rods cannot take the revs (Carrillo are the best), you will want to go to a solid lifter billet cam and reduce the valvetrain weight. The production intake will not make power at those revs so a short runner or multiple throttle body system should be used. Dry oiling will eliminate the windage problems. Pair all this with a good engine management system and you are ready to tune.

The bottom line is, to build a reliable engine like this means you need to replace almost everything. It is more cost effective to build a motor that makes power in the 3500-6500rpm range.

 

[Janni]

Dan,
Can't you read - money is no object. And he doesn't want anyone telling him what's the most cost effective thing, etc. He just wants ANSWERS.

In fact, he'd like all the knowledge from all the tuners to be placed here - documented - for free - so that he can do all this work at his own shops.

However, he knows WHAT he wants, but wants everyone to help him get there and does't want superfluous information like the fact that there's a reason tuners build Viper motors the way they do. Please - don't muddy the waters with knowledge from years of building Viper engines.

Thank you.

 

[Svsi]

Gentlemen
I would like to add information that is helpful tuning the V-10 to 8000revs.
#1 Lightweight componets in the valve train,titanium valves,or lightweight
stainless valves.The 2.20 intakes with 1.65 exhaust.
Solid roller cam gun drilled that has the lift 600+ to raise the torque,
titanium lifters. GTSR CNC heads,dry sump.
#2 Gen1 or Gen2 heads that have the same componets and are prepped the
same way as #1.
#3 SVSI has run there car 7500 with the stock intake.I know for a fact that
Canaska/Sothwind ran the stock intake 8000+ in the n/a GTSRs that they had.
#4 Walker Evans raced there trucks 1000miles on GEN1 heads with only 6500rpms
maximum.There valves were twice the stem size and weight as the stock
valves.There valves were stainless and only 2.02s 1.60 exhaust.There engines
only had 1:60 ratio t&d rockers.They ran making 725hp with dry sump.So
when you look at the different motors,was Walker building a stronger motor
than the GTSR? Walker also used solid billet roller cams and solid lifters
but they were not lightweight.The Walker Evans block was iron with steel
billet cranks and billett main caps and girdles. GTSR blocks all aluminium
with the HEMI crank size,billet main caps.
#5 I believe that the aluminium motor would not hold up to free reving that
was done during the 1000 mile. But the Walker Evans wold hold up in a
American LeMans race.JUST AND OPINION WHAT DO YOU THINK ????

SVSI
Ron Sr

 

[3snakes]

WHY not remove tack get rid of the red paint? est. is 2.50 if you do it yourself.......

 

[Daniel Cragin/DC Performance Inc]

I remenber the development of those Walker Evans motors and they went through quite a few engines. Biggest problems were the crankshafts. The problem with the long runner manifolds had to do with reversion at lower engine speeds and the long duration cams (hard to tune down low) and the runner length hurt hp. The engine could be run to 8k with the stock intake, you just could not get the best power at those rpms.

 

[joe117]

Dan, I hope you aren't telling this guy it can't be done.
He gave very specific instructions that he didn't want to hear that from anyone.

"if you dont know the answer to a TECH question refrain from offering opinions as to why something is a waste of time, too expensive, or that it doesn't make sense to you that someone wants to do it."

If I were you I'd watch out before you get into trouble.