I have to say the LS7 is a very impressive engine, it’s amazing that it can rev to 7000 I am surprised they didn't put the ls7 in the zr1 but I understand why they didn’t. but I still think the v10 is the motor to have and my 8.4 with variable timing and awesome race heads is amazing motor i think it has more potential than the LS7 when it comes to big HP.
Once the FI kits come out for the 08-up Vipers it's going to be cool. At this point the problem is no matter what you do to them your right around 600 whp. My Heads/cam Gen 2 has 612 rwhp so it's hard for me to make the jump.
But once there is DIY blower out for the gen 4 it's going to be game on. Hell it should make 900+ crank HP at 8psi (800ish wheel). Thats a hell of a bolt on car! Add headers/exhaust, 10psi O MY!
I'm waiting....
I would tend to doubt that the stock internals are going to withstand 800hp. A normally aspirated Gen 4 motor with well over 700 is within reach as demonstrated by the Challenger V10 drag pack.
Expecting that kind of increase is unfair and unrealistic. You have to remember the total surface area subjected to pressure is much higher on the viper than the lsx and stealth engines. Bigger bore, and more cylinders with similar pressure means a significantly higher amount of total stress.700 at the crank is easy on a gen 4 as demonstrated by the 600-620 RWHP gen 4 vipers out there. But there is a big difference between 700 crank HP and 700 WHEEL HP.
And dear god I would sure hope a 8.4L V10 that makes 600 hp stock can suport 900hp crank (~800 rwhp)with mods like a blower on stock internals. I have made 800 AWHP (over 900 crank) out of a stock 3.0L V6 in one of my stealths, cast pistons and from a motor that only made 300hp stock. I also have made 700 rwhp out of a Stock bottom end 6.2L LS3 with heads/cam/ blower on pump gas in a 2010 camaro And thats double the power at the wheels the car made stock. It's taken a daily beating for a yr and still runs like a top.
If the gen 4 Viper motor cant withstand a 50% power increase on the stock block Dodge needs to go back to the drawing board because every other modern motor can, and can with ease.
If your going to pull the trans to replace 5th...might as do it right and use this gear set up.
This setup will allow you to use 1st to start with. It also allows you to in effect have a "higher" redline as you can hold each gear for a higher mph. With most drops going from 6000rpm to about 4500rpm...you have a nice tight ratio to stay in that small power band.
Rear 2.73
1st = 2.66 (66mph) (50mph = 4500rpm)
2nd = 1.78 (99mph) (66mph = 4000rpm)
3rd = 1.35 (130mph) (99mph = 4550rpm)
4th = 1.00 (176mph) (130mph = 4450rpm)
5th = 0.84 (209mph) (176mph = 5050rpm)
6th = 0.56 (314mph) (70mph = 1350mph...great mpg )
Expecting that kind of increase is unfair and unrealistic. You have to remember the total surface area subjected to pressure is much higher on the viper than the lsx and stealth engines. Bigger bore, and more cylinders with similar pressure means a significantly higher amount of total stress.
Nice plan there. Do you know if all those gear sets exist, including the 2.73 rear gear?
2008+ Viper 8.4L Engine (rated 600 hp)
Bore x stroke 4.055 x 3.96
Compression 10.2:1
Redline 6,250 rpm
2006+ LS7 7.0L Engine (rated 505 hp)
Bore x stroke 4.125 x 4.00
Compression 11.0:1
Redline 7,000 rpm
2008+ LS3 6.2L Engine (rated 436 hp)
Bore x stroke 4.0065 x 3.622
Compression 10.7:1
Redline 6,600 rpm
There are hundreds of LS3/LS7 cars out there pushing 650-700 rwhp (740-800 crank hp) on stock internals, using mostly Prochargers or turbos. As you can see, the LS7 has a higher CR, larger bore and stroke than the Viper engine does. I'd expect the factory 2008+ V10 to be at least 750-800 rwhp capable, if the pistons/rods could hold up. That is the main question.
Nice plan there. Do you know if all those gear sets exist, including the 2.73 rear gear?
QUOTE]
You bet. Common T56 gear ratios. You might want to go a little higher on 1st but it would be super tall and a PITA in a parking lot That would help with the rpm drop between 1st and 2nd. But...you could start a 50-150 roll-on from 1st.
. Just because you can double the HP of a 300 HP engine without changing internals doesn't mean the same should happen with a 500 HP engine.
Expecting that kind of increase is unfair and unrealistic. You have to remember the total surface area subjected to pressure is much higher on the viper than the lsx and stealth engines. Bigger bore, and more cylinders with similar pressure means a significantly higher amount of total stress.
Try Triple the HP of said 300hp V6
And I'm not asking for Triple, or even Dbl, but dear god 50% more, thats not asking for much. Hell I added nearly 54% RWHP to my 2001 "cream puff" Gen 2 viper by simply doing striker heads/cam/header/exhaust/tune (399 rwhp to 612 rwhp)
Did you really just say that a V10 8.4L motor making 900 hp at 8psi of boost there is MORE stress on the motor then a 3.0L V6 making 900 hp at 30psi of boost?
Man we better call the Top fuel guys and tell them to go down to 1.0L single cil.motors. They will be under less stress at 8000 hp then there 500 cid V8's are! think of all the money they will save on motors!
You dont need to be a rocket scientist to know that making 4.92 HP pre Cid on 6 rods, 6 pistons, 4 main caps is harder on parts then making 1.75 hp per Cid on 10 rods, 10 pistons, 6 main caps .
Sorry NineBall I think be have got your thread way off Topic..... End Hijack
If your going to pull the trans to replace 5th...might as do it right and use this gear set up.
This setup will allow you to use 1st to start with. It also allows you to in effect have a "higher" redline as you can hold each gear for a higher mph. With most drops going from 6000rpm to about 4500rpm...you have a nice tight ratio to stay in that small power band.
Rear 2.73
1st = 2.66 (66mph) (50mph = 4500rpm)
2nd = 1.78 (99mph) (66mph = 4000rpm)
3rd = 1.35 (130mph) (99mph = 4550rpm)
4th = 1.00 (176mph) (130mph = 4450rpm)
5th = 0.84 (209mph) (176mph = 5050rpm)
6th = 0.56 (314mph) (70mph = 1350mph...great mpg )
First of all, I never said anything about a 900 hp 6 cylinder being under less stress than a 900 hp 10 cylinder. The fact that you claimed I said so is quite silly since you are quoting me in my response.
Expecting that kind of increase is unfair and unrealistic. You have to remember the total surface area subjected to pressure is much higher on the viper than the lsx and stealth engines. Bigger bore, and more cylinders with similar pressure means a significantly higher amount of total stress.
To your point though, I do hope that one day a Viper comes stock with forged internals similar to a Ford GT. However, I'd rather it not and stay under $150K, which I believe is the direction the Viper would go if it took that route. Remember, they have to add all the electronic nannies for the Gen V. The R&D from that, plus the actual equipment I fear will put the Gen V Viper at a starting point of $120K.