Best heads and cam combo for '00?

[Jason Heffner]

Re: Best heads and cam combo for \'00?

There are a number of tuners who offer a cylinder head upgrade for gen 2s including TNT, BTR, The viper Shop, and myself. Seeing that you live in California I would strongly recommend talking to Dan Cragin at The Viper Shop. He has as much Viper experience as anyone and should definitely have what you're looking for. Good luck.

 

[treynor]

Re: Best heads and cam combo for \'00?

Sheyster,
I've done a fairly detailed staged buildup of my '01 RT; you should see my viper page for the full scoop. If you just want the net-net, you can get 495-520 RWHP from any Gen-II car with just the following mods:

Stock airbox w/Tubes & Filters
Headers (Belanger, Hennessey, TNT, CDI, probably others)
3" High-flow cats or no cats + APEX snakebox
3" catback exhaust (choose by sound; they all flow enough)
T&D 1.7 roller rockers
Ported heads w/oversize stainless valves; look for flow #s of 270+ CFM intake & 210+ CFM exhaust at .60" lift.

Well-documented buildups by both Tom Welch (BTR Viper) and myself have demonstrated that you need no other mods to reach those power levels. Several tuners go a bit beyond that power level by swapping cams (especially useful on '00+ cars), extrude-honing the intake, etc.

 

[Chuck 98 RT/10]

Re: Best heads and cam combo for \'00?

Ben, got any pics of your Valaya racing front brake ducting kit?

Does the head job include valve job and is it the typical 3 angled valve job or is there a more productive one for the Viper heads? Or are the heads just polished and ported?

 

[treynor]

Re: Best heads and cam combo for \'00?

Chuck,
I don't have pictures of the brake duct kit, but I can report that it was quite effective. I ran my RT at Buttonwillow with Goodyear racing slicks, EBC yellow front pads, and the ducting kit, and not only never got fade but actually got ABS actuation on the front wheels coming into a couple of slow corners. If you have more detailed questions, I'd call Ted May @ Valaya directly (408.448.8811) -- he's a great guy, and has a lot of experience with customers who roadrace their Vipers.

The heads *I* used were done by Hennessey's shop, and like most tuners he wasn't overeager to spill the exact details of what he does (nor should he be). However, since the valves were replaced it's safe to assume some basic valve job was done; I've not heard of any particular gains to be had by more extensive valvework, as the main bottleneck at the 520+ RWHP power level seems to be the intake manifold.

 

[FastMatt]

Re: Best heads and cam combo for \'00?

the intake cant be that bad, check out this link
http://vca1.viperclub.org/ubb/Forum7/HTML/000346.html

 

[treynor]

Re: Best heads and cam combo for \'00?

The intake IS that bad

For the LPE 542 package, they take a stock intake, saw it in half, port it extensively from the inside, then weld it back together -- see this link, bottom of page 1: Car & Driver LPE 725 review . I did a fair bit of research on this exact topic back when I was building my RT as a N/A car, and at higher HP levels the intake becomes a bottleneck. Extrude Honing it alone is apparently good for about 10 RWHP once you've done heads+cam; Lingenfelter takes a more extreme approach.

 

[FastMatt]

Re: Best heads and cam combo for \'00?

so what els can be dun to the intake for more flow?

 

[Tom Welch]

Re: Best heads and cam combo for \'00?

Matt,

Believe it or not your intake is not the most restictive part. A correctly ported head will draw more air through the intake. Extrude honing the intake is well documented on this site and has shown only a minimum gain in power. Its simple, my own viper makes 800 rwhp through the stock intake and throttle bodies with the stock cam(over 500 rwhp N/A).

The correct COMBINATION of parts is the key.

Why reinvent the wheel and waste more money doing it?

Tom
Http://btrviper.com

 

[Joel]

Re: Best heads and cam combo for \'00?

Can the standard ECU cope with the extra airflow enabled by improved heads. Seems to be well outside the 10% extra that it can cope with. Already with the limited mods that I've carried out the part throttle mixture feels a little weak, although our euro spec vipers have some ecu differences from US ie; only two forward O2 sensors

 

[treynor]

Re: Best heads and cam combo for \'00?

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Can the standard ECU cope with the extra airflow enabled by improved heads
<HR></BLOCKQUOTE>
Yes, it can. My 515 RWHP car used the stock ECU. WOT mixture and part-throttle driveability were both fine.

 

[Joel]

Re: Best heads and cam combo for \'00?

Its good to know, now I'm tempted !

 

[LTHL VPR]

Re: Best heads and cam combo for \'00?

Great question! Many people don't understand the importance of matching the camshaft with the heads.

Since we performed just about all of the installation work on Ben Treynor's 00 RT/10 (treynor) including heads, headers, NOS/Propane kit, etc.. at our Viper shop in Northern California, we had a solid dyno baseline to build our LETHAL 500, 600, and 650 performance packages.

Some important things to consider when adding a camshaft:
1) Will it pass emissions (many camshafts are too aggressive to pass emissions)
2) What is the final driveabililty (idle quality, hanging idles, startup)?
3) Does the installation facility have an their own dynojet and Viper tuning software (your car will need some tuning to run safely)?
4) Is the final parts designed to be used on street, track or BOTH?
5) What other work is performed to insure ultimate reliability?
6) Are the prices for installation fair and reasonable?

We are very pleased with the final results of our LETHAL 650 on a 2001 Viper. The major power components of this package are heads w/matched camshaft, and intake, throttle body and airbox mods. Since YOUR Viper is a 2000, I would expect the results to be similar since the cars have the same stock parts to start with. If you would like a detailed list of ALL the components click here: http://vca1.viperclub.org/ubb/Forum24/HTML/000156.html

HERE ARE THE DYNO NUMBERS:
STOCK 2001 ACR (w/K&Ns & tubes): 398hp, 442tq
ADD headers: 432hp, 479tq
ADD LETHAL 650: 572hp, 587tq

The car passes emissions, comes with custom computer tuning to ensure maximum reliability, and, best of all, the power is available all the time!

If you would like more information about your Viper, our packages, or potential mods, I would be more than happy to help you make educated decisions(408.562.1000).

Good Luck!
-Wayne (LTHL VPR)

 

[Joel]

Re: Best heads and cam combo for \'00?

Sorry to labour this point, but in what way does the ECU compensate for increased airflow, does it hold each injector open longer to inject more fuel. What happens at WOT when I believe the fuel/ignition map is factory preset and doesn't 'learn' ?

 

[GTS Dean]

Re: Best heads and cam combo for \'00?

Joel,

I believe that the ECU can change the injector pulse width up to 66% off the baseline map for closed-loop operation. WOT is open-loop, but it feeds lots of extra fuel. Increasing fuel pressure is the easiest way to get past the constraints of the stock system, but that requires a bit of rework.

 

[treynor]

Re: Best heads and cam combo for \'00?

To reiterate, however, you do not need to do anything to the fuel system or ECU at the ~510 RWHP level. For example, here's my dyno chart from the day after I installed heads & roller rockers in my '01 RT/10, kicking the power from 438 RWHP to 515 RWHP:

You must be registered for see images

This car had the stock fuel system and stock ECU. Note the nice safe A/F curve.

FWIW, the blue lines were the best dyno runs from when the car had headers / exhaust / hi-flow cats / filters / tubes...

 

[FastMatt]

Re: Best heads and cam combo for \'00?

man look like with stock heads, hp REALY drop off after 4500rpm!
the heads/rocker set up peek #'s done shock me, but at 5500rpm you picked up like 150hp!!! holy crap!

 

[HouseofSpeed]

Re: Best heads and cam combo for \'00?

Good discussion on the topic at hand...and I definitely agree that COMBINATION is the key.

The intake is the restriction on a car with a good set of heads...Tom, the only reason you are making 800 is because you are supplying your own atmosphere (N20). If the stock intake were meant for anything other than a production car, why wouldn't it be used in competition? Because it is a piece of crap and a huge compromise on a modded street car.

Joel, unfortunately..the stock PCM and the programming behind it are mismatched as well. You can make power with it, but as with any speed density system...changing the vacuum signal at idle and part throttle through an increase in airflow and valve timing changes can and often will compromise driveability/emissions/fuel economy (not that we buy Vipers for their fuel frugality).

There are many competent shops/tuners out there...it is not nearly as one-dimensional as it once was....competition making it a better buyer's market. Choose wisely and outline your performance needs to the shop you choose. If I can be of any help, feel free to call or e-mail. Good Luck.

 

[Martin D]

Re: Best heads and cam combo for \'00?

Kyle,

Good points! Lets get your new custom intake on my car and see just how restrictive the stock intake is.....looking forward to the piece! I am betting 600/600 at the tires.

Regards,

 

[Tom Welch]

Re: Best heads and cam combo for \'00?

Kyle,

I have to disagree with you. Horsepower is horsepower and it takes all aspects of a correct combination to achieve it. Don't believe me? take 2 pistons out and go to the dyno.

The stock intake and throttle bodies will accomodate enough air to make 550 rwhp(naturally aspirated..much more with forced air induction or nitrous) with drivable compression. After that its spend 10,000.00+ for an aftermarket piece that is NOT designed for the low rpm, high torque application of the typical customers Viper engine.........including my own.

A good topic though.

Tom
Http://btrviper.com

 

[Anthony - 98 GTS]

Re: Best heads and cam combo for \'00?

Although I don't have my car together yet, I am in the middle of a significant project on my '98 GTS with Kyle at House of Speed here in Houston.

Since I have never driven my car, I unfortunately won't have any baseline numbers to compare. My car started with a base Venom 500 Package and we are performing the following upgrades:

--BTR Intake Tubes with K&N Filters
--Extrude Honed/Ported Intake Manifold
--Ported/Polished cylinder heads with larger intake/exhaust valves, new valve guides, retainers and heavy duty springs
--T&D 1.7 ratio shaft rockerarms and hardened steel pushrods
--Custom roller hydraulic camshaft upgrade
--Lifter upgrade
--Fuel system upgrade
--1.75" headers with 5-to-1 merge collectors
--3" exhaust system with high flow cats
--Aluminum flywheel
--Aluminum pulley upgrade
--Flyuidine radiator
--180 degree T-stat
--3.45 rear gears
--and finally a healthy shot of NOS

As soon as we get her together I will post my dyno numbers. I already have a roll bar and 5-point belts so I will also post my track times when we are done.

Anthony

You must be registered for see images

 

[Tom Welch]

Re: Best heads and cam combo for \'00?

Anthony,

Good luck on your project. You are in good hands with Kyle as I have heard nothing but good about his work.

Tom
Http://btrviper.com

 

[SoCal Rebell]

Re: Best heads and cam combo for \'00?

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by FastMatt:
man look like with stock heads, hp REALY drop off after 4500rpm!
the heads/rocker set up peek #'s done shock me, but at 5500rpm you picked up like 150hp!!! holy crap!

<HR></BLOCKQUOTE>

Matt, you can say that again, Ben took me for a ride last summer, our cars were similar except he had heads & 1.7s and WOW what a difference, it seemed like she just kept pulling, I was very impressed. Then he hit the nitrous button and it was, see ya later.

 

[treynor]

Re: Best heads and cam combo for \'00?

Hey Ron,
Just wait until I give you a spin in my intercooled stage III DLM car! You thought that NOS hit was fast? That was "only" about 580 RWHP