Power Question

superdavz

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I have been reading alot about the differences between the Viper and the Z06. I dont understand why a Z06 can put on a set of headers and put in a cam with the result being 550rwhp. If my thinking is correct when paxton brings out a kit for the Z06 wont we be out matched?

If the VIPER already comes with headers and I have read about people putting cams in their cars and only picking up 30-40rwhp. I'm just trying to figure this out.
 

Viperchad

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Good question bro.....Obviously after hearing Joe say that the other night.....I was a bit concerned too. BTW....welcome to the GENIII boards buddy....aren't you gonna announce your latest addition to the board??????
 

jpas

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I have been wondering the same thing. Why do the Vipers run such a low compression ratio? Has anyone tried a 10.5:1 or 11:1 on a Viper engine with a big CAM.

The stock headers are not comparible to a set of long tube headers with a good merge collector.

I was going to go with a Turbo setup, but I think I might try a custom CAM, high CR, ported heads and make a set of long tube headers and see what happens. I am sure that there is also a good amount left in timing and fuel.
 

SweetRed04

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I have been wondering the same thing. Why do the Vipers run such a low compression ratio? Has anyone tried a 10.5:1 or 11:1 on a Viper engine with a big CAM.

The stock headers are not comparible to a set of long tube headers with a good merge collector.

I was going to go with a Turbo setup, but I think I might try a custom CAM, high CR, ported heads and make a set of long tube headers and see what happens. I am sure that there is also a good amount left in timing and fuel.

I'd bet its low because that was all that was needed to meet their 500 HP goal. Why would they go higher than necessary - the Viper V-10 is clearly a lightly stressed engine. The low compression ratio also makes it easier to turbo or supercharge compared with engines in the 10.5 or higher ratios. (High compression and forced induction usually lead to short engine lives.)

DC gets 425 HP out of the much smaller (about 25% less displacement) SRT-8 Hemi enigne. If the V-10 were tuned to that level it would have about 575 HP.
 

VENOMAHOLIC

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I have been wondering the same thing. Why do the Vipers run such a low compression ratio? Has anyone tried a 10.5:1 or 11:1 on a Viper engine with a big CAM.
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It has been done by Dodge since 1995. It is known as the Viper GTS/R. It was estimated the 1996 version, even with a pair of intake restrictors, made at least 650 hp. It went 0-60 in 2.9 sec and to 100 in 5.4. 1/4 mile was 10.3 at 143.9mph. The GTS/R weighed then 2500 lbs.

There really is not as much difference between a Viper race car and a street version as found in other makes. They run high compression and beefier internals but with a very similar block and drivetrain. It has been argued that the C5R and C6R run entirely different engines than stock which is how they have been successful.

The hard part is getting a high compression Viper engine to pass emmissions. Vipers in racing always have the largest restrictor plates because the V10 engine is so much better than the other makes that if it wasn't it would win every time.

This is why I prefer the Viper even over the new Z06. The Z06 (I guess) runs 10.75/1 cr on a 427 and gets 500 hp. On only 9.06/1 cr, the Viper gets 505 SAE hp. I am not sure exactly what the V10 would get at 10.75/1 cr but a guess would be well over 675. :2tu:
 

Green Viper

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On my Gen 1 Viper (originally 400 hp) we did some minor head work but increased the compression ratio to 10.2:1 and it dynoed at 483 hp/501 lb-ft at the rear wheels.

This was without tuning the A/F or timing and with 70mm throttle bodies (cost some torque) and the usual mods of K&Ns/hi flo cats, Borla exhaust & headers. It ran fine on pump gas even 91 so I have a feeling we could have gone more aggressive to at least 10.6:1. I was told by several experts there was at least 40 more horses by playing with the A/F and timing, more if I upgraded to a better camshaft.

Since the SRT-10 starts with 110 more ponies than my Gen 1, it is not unreasonable to get mid/high 600s (or more) at the motor by doing the same things I did to my Gen 1.

What do you plan on doing with the power? Honestly, when you get much more power you need a plan with itmes like uspension, braking, cooling and other systems. Somewhere around 600 the tires start to be a weak link for the street, especially if you have 3.55 or higher gears.

Best of luck!
 

WILDASP

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What do you plan on doing with the power? Honestly, when you get much more power you need a plan with itmes like uspension, braking, cooling and other systems. Somewhere around 600 the tires start to be a weak link for the street, especially if you have 3.55 or higher gears.

Best of luck!
Bingo!You just identified the main problem,at least for the street.(A car running on race tires,ie.slicks,is a bit different animal)For the sake of simplicity,let's take the SRT10 and the new Z06,both with just over 500HP at the crank.Both are already somewhat traction-challenged on street tires.I drive both,so I have no particular axe to grind here.Say we add 100rwhp to each.We then have a problem with getting that power to the pavement,so we go to stickier tires(if we can find them).
Now that we've hooked up the power better(and quicker)we place more stress on the driveline and suspension components.Beefing them up adds weight,so we get into a weight vs. reliability trade-off.As if that weren't enough,we reach a point of smaller returns for the additional horsepower,that is,a 20% increase in HP does NOT yield a 20% increase in performance.I'd tend to agree that,for the street,we're about done for balanced and reliable performance at around 600rwhp, with either present platform.With the Viper,we can easily reach that through forced induction(supercharger or turbos)with a modest amount of boost.With the LS7 engine,the Vette will have to make the additional power with a cold-air intake,headers,cam and tune;with the high compression,they can't just bolt on a forced induction without modifying the heads,pistons and possibly other internals as well.The general thinking on the Vette side is that if GM does a supercharged Vette,they'll most likely start with the lower compression and smaller LS2 engine,getting a bit over 600HP at the crank,or about 540rwhp.This is in the same range that we might expect from the current LS7 with the mods mentioned above.We already know we can get more than that from the current Viper engine,whether normally-aspirated or forced induction,with mods that are already well-proven from a reliability standpoint.Stock-for-stock,the two cars are about even,with the Vette having a slight edge-with reasonable mods,edge goes to the Viper.
 
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superdavz

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Thanks for all the information guys. This question was more for my own curiosity than anything else. The guy that works with me just got a new Z06 and has been telling me a lot about all the power they can make with the few things that are available. I personally will get my new coupe in about 2 months or when its finished. I don't really plan on racing *********, I have a gen 1 for that. I just want to put on some more power to have fun with and to kick some ***!
 

WILDASP

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Thanks for all the information guys. This question was more for my own curiosity than anything else. The guy that works with me just got a new Z06 and has been telling me a lot about all the power they can make with the few things that are available. I personally will get my new coupe in about 2 months or when its finished. I don't really plan on racing *********, I have a gen 1 for that. I just want to put on some more power to have fun with and to kick some ***!
In that case,simply bolt on a Paxton and enjoy! :D
 

Paul Hawker

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A lot of potential power is locked up in the heads. A good head massaging will give you quite a bit of power.

Don't worry too much about the Z06. They have lots of problems on their own. Overheating on the track, can't change out tires or adjust pressures without instigating traction control.

Be very happy with your Vipers. I would not even thinking of trading our "problems" for theirs.

Just try getting an aluminum chassis repaired at a regular body shop. Try putting on a set of track wheels or tires, Try hopping up the engine, and then sorting out the traction control. Try holding your body in the woogy seats on a road course. Try to run more than a few laps on a hot day. Try upgrading the suspension. Try fitting a roll cage. Try convincing anybody not into cars that it is worth more than a standard vette. Lots of issues.
(However it is a fantastic street car).
 

Andrew/USPWR

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Without going into the motor, TT or Super Charging. What can be done, just to get a little more HP. I don't want to void the warranty or make it any louder. I know that doesn't leave much. I’m looking to mod a future SRT/10, to have a little more HP than stock but still be a SL55 type daily driver. I keep thinking, changing the gear ratio in the dif might be the trick.
What say you guys?
 

WILDASP

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Without going into the motor, TT or Super Charging. What can be done, just to get a little more HP. I don't want to void the warranty or make it any louder. I know that doesn't leave much. I’m looking to mod a future SRT/10, to have a little more HP than stock but still be a SL55 type daily driver. I keep thinking, changing the gear ratio in the dif might be the trick.
What say you guys?
You can pick up a little in the intake with K&N's and go to a 3.55 rear gear-You'll give up some on the top end but be a bit quicker.A number of guys here who aren't running big power have done the 3.55 rear gear and most seem to like it.I haven't done it simply because I'm still considering a Paxton,and the 3.07 works better with that set-up.
 

Andrew/USPWR

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Thanks Bill, I'm not concerned with top end because, who needs to go 200mph? But what will those gears do for slow drivability? Owning a Gen II and the jumping it starts doing at low rpms and slow speeds, is what I’m trying to avoid.

Andrew
 

Vipermann

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Without going into the motor, TT or Super Charging. What can be done, just to get a little more HP. I don't want to void the warranty or make it any louder. I know that doesn't leave much. I’m looking to mod a future SRT/10, to have a little more HP than stock but still be a SL55 type daily driver. I keep thinking, changing the gear ratio in the dif might be the trick.
What say you guys?

It will be hard to pick up any significant power without putting your warranty at risk (depends on the dealer) ... if it doesn't risk the warranty, it probably doesn't affect the power that much either (there's no free lunch). Having said that, I've added the following:

>K&N
>B&B 3" exhaust (no headers)
>T&D 1.75 roller-rockers (stock springs, w/hardened push rods)

... dyno runs pulled about 464 rwhp, a gain of about +28hp ... I'm pleased ... based on those gains with just the 1.75 rockers, I'd believe there was a lot to be gained in the heads ... but I picked up a little HP the cheap and easy way, without taking the heads off ... my next HP move would be to tune with a VEC2 because the AFR on the dyno showed a high number down low, and tons of gas up high, so I'd guess there might be another 15-20hp there with some more gas down low, and some timing added in the higher rpms ... but ... the VEC2 would be another step toward a potential warranty arguement if I ever have a problem ... (there's no free lunch). Good luck.
 

Vipermann

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btw, the B&[******] were a b_tch to install, and required custom pipe work without headers (they're made to go with headers), but I haven't found any jet-coated stainless steel headers yet, so I held off on getting those ...
 

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