New Lethal 750 dyno numbers

[Bill/APEX Motorsports]

Thanskgiving morning, we did the final tuning on our Lethal 750 with our new headers and slightly more aggressive camshaft. The numbers ended up at 671rwhp and 715rwlb/ft. torque. with a very nice air/fuel ratio all the way up. This is all normally aspirated, 550ci power!

The car is an absolute rocket. Thanks to the stock 3.07 gears, the acceleration is blistering yet very smooth. Of course, with over 600rwlb/ft torque from 3,200rpm up, you still have to be careful with the throttle.
And to make the block plenty strong to handle the extra power, we added our new billet main caps, which increase twisting strength roughly 50% over the stock caps.
I'll post dyno pictures soon...

 

[Supra]

DANG! Congrats! Pardon my ignorance but is this the most powerfull normally aspirated, NO NOS package available for the Viper?

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Bill/APEX Motorsports:
Thanskgiving morning, we did the final tuning on our Lethal 750 with our new headers and slightly more aggressive camshaft. The numbers ended up at 671rwhp and 715rwlb/ft. torque. with a very nice air/fuel ratio all the way up. This is all normally aspirated, 550ci power!

The car is an absolute rocket. Thanks to the stock 3.07 gears, the acceleration is blistering yet very smooth. Of course, with over 600rwlb/ft torque from 3,200rpm up, you still have to be careful with the throttle.
And to make the block plenty strong to handle the extra power, we added our new billet main caps, which increase twisting strength roughly 50% over the stock caps.
I'll post dyno pictures soon...

<HR></BLOCKQUOTE>

 

[Bill/APEX Motorsports]

To tell you the truth, I'm not sure if this is the most normally-aspirated hp.

It very well could be! Can anyone out there claim more?

 

[MES]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>
671rwhp and 715rwlb/ft. torque
<HR></BLOCKQUOTE>

Impressive, I want one. Let me know when your 750 package goes on sale, maybe a 50% off Christmas special

Are you ever going to take it to the drag strip? I bet that's enough power to go into the 9's which would make you the first all motor Viper into the 9's That's some good bragging rights/publicity

 

[Bill/APEX Motorsports]

MES, yes we're going to try to get to a drag strip soon. With only two within a two hour radius, and the fact that the rain's going to start soon, it might be a while.

We'll get there as soon as we can, though!

 

[Anthony - 98 GTS]

Bill,

Great numbers for N/A. You need to bring either a shop car or a customers car to the Viper Powerfest in Houston/RCR in January.

I would love to see one of your cars up close.

 

[Toronto_ACR]

can you post some pictures of the car and engine for us. It is very impressive. How releaible is the engine since it is stock block, heads and crank.

Thanks

 

[Torquemonster]

Excellent effort Bill!

what rpm's would you be comfortable turning in that baby?

The new SRT 10 heads may offer the opportunity for even more power when they are available! Good work.

 

[LTHL VPR]

Torquemonster-
Looks like you dug this one up from awhile back.
We spent hundreds of hours testing all sorts of naturally aspirated parts on Vipers to come up with the LETHAL 750.

Our goal was that we wanted a car that was mild mannered enough for the street, but had ungodly amounts of power and torque for an engine-only setup. We felt this was the best way to make power consistently, reliably, and would maximize the longevity of the engine, tranny, and drivetrain.

We used the highest quality parts available, and strengthened any weaknesses in the engine, drivetrain, and cooling systems.

The end result was a car that anyone could drive (stock-like drivability), but would stand up to 'abuse'. Some people don't realize that the best parts for the street that offer ultimate longevity, are not necessarily the same goals in mind when people build engines for racing. In that industry, many times engines are torn down after every race and rebuilt; parts and components are not necessarily made to last with no adjustments for thousands of miles like a street car (2 totally different goals).

To that end, for the LETHAL 750, the car reaches peak power and torque in almost the same rpms that a stock Viper does. The Viper engine is not a great design for a hign reving engine. I never need to take mine above 5900rpms to feel everything it has to offer. Again, this was another one of our goals. The less rpms, the less stress you place on the engine.

TORONTO ACR-
Look at the website for more info on the engine....you are incorrect in thinking these components are stock! The LETHAL 750 uses the stock block, and that's about it. We use MOPAR heads, a custom billet-keyed stroker crankshaft, forged pistons, billet rods, custom camshaft, custom designed billet maincaps to significantly increase the strength of the block, as well as dozens of other power and reliability enhancing parts.

Hope this answers your questions.
-Wayne

 

[Torquemonster]

oops I just looked at the date of your original post - someone bumped it and i didn't check.

I appreciate your reply and I like your engine philosophy. We may need to talk, I want my Viper engine done in the USA before I import as although I know some specifics I will be wanting in it - I don't wish to pay for someone over here to experiment at my expense... I'd rather pay someone like you who has the experience with those engines.

I'm still undecided about boost - I'll never settle that one until I try it out to see if i like it or whether it's too much of a good thing to live with compared to an all engine 750hp.

I've always wanted 1000hp - but until you drive it, it's hard to know whether I'd actually enjoy it. Our roads aren't that good compared to your interstates. It may be 750hp is more than "adequate"

 

[LTHL VPR]

Torquemonster-

I think 750 hp and 800 tq is plenty for the street! When I drive the car, I feel like it is right at the limit of adhesion for the tires through 3rd gear, but somehow the tires stick most of the time.

If 1000hp is what your goal is, I can tell you that you will be wasting horsepower and most posted speed limits as your tires search for traction. However, we aim to please!!

We are just putting the finishing touches on my car.....the new, LETHAL 1000!!! (we are 1 step ahead of you!).

This car is the LETHAL 750 + a small amount of boost. With lower levels of boost, heat does not become your enemy, and your engine is not 'pushed' as hard! No intercooler is required, and the installation is much cleaner. Once my car is finished, I will post some pics for you. Couple things you will notice...GOALS:
1) Supercharger kit is the first Carb certified unit (legal for the street in all 50 states)
2) No external fuel rails, no extra injectors (clean, stock look)
3) No intercooler to sit in front of your radiator to block precious air flow
4) Will enable you to use an aftermarket radiator (still working on this, but very close...).

Regards,
Wayne

 

[Torquemonster]

Thanks Wayne

look forward to seeing you post the results!

re 5900rpm - you gotta turn 6 man! There's something about seeing 6000rpm on a big engine - its addictive ... but know what you mean - powers under that.

I understand the goals - makes for a neat and tidy installation with minimum things to go wrong - will appeal to most customers who'll try before buy and be sold.

Have you considered Aquamist water injection as an alternative to intercooler as a way to keep air temp down on hot running? Takes up hardly any space.

BTW - I believe a tight quench is possible even with a boostable compression on the V10 - that and ceramic coating will help reduce any detonation problems without excess spark retard.... just thoughts!

 

[Paolo Castellano]

&lt;BR&gt;And to make the block plenty strong to handle the extra power, we added our new billet main caps, which increase twisting strength roughly 50% over the stock caps.

[/QUOTE]

Bill, how do you measure that the billet main caps have 50% more strength in resisting torsional loads? Is that while the motor is assembled or just compared to the stock caps metalurgically speaking?

 

[Torquemonster]

Paolo - this experience with custom caps may help....

the old B/RB Mopar blocks used to flex as they were a bit weak in the webs at the bottom - which limits the 440 block to around 600 reliable long term hp without some help. They were not 4 bolt mains like the hemi.

So, someone started making billet aluminum caps- the theory being to absorb the vibration and therefore allow the block to take more before cracking.

Fact was the vibration goes UP not down - so it didn't work - in fact made it worse...

They then went to billet steel caps - and these can help to reinforce the bottom end, but won't eliminate block stress over a certain hp level. On the 440 these lifted the safe hp to around 800 for drag racing anyway - so that's worthwhile.

Beyond that - we ended up having to build a thick steel girdle plate between the sump and block, and then grout the water jackets. This was good for around 1400hp.... after that it was aluminium block time.

Lesson - a good steel cap can improve the bottom end strength - but only within the limitations of crank and block.

 

[WESTCOAST JASON]

Very, Very nice! What is the largest inch Viper motor out there? Is this the one? 550 inch? Thanks in advance!