Heffner's Prototype Twin Turbo Viper GTS

[Viper TT]

Heffner\'s Prototype Twin Turbo Viper GTS

It is alive and well! Jason has definitely raised the bar with this twin turbo kit!

I am normally a person who turns his own wrenches and describing my personality as "particular" would be an understatement. Initially it was very difficult for a person of my nature to drop off my vehicle for someone else to work on, but this type of project was out of my league. Jason is one person I would not hesitate to take this and any future vehicles to for any type work. It has been an honor to work with someone of his caliber.

Enough rambling about my personal hang-ups!

Jason's research and engineering in developing this kit is phenomenal. Stating that this kit is an absolute work of art, doesn't even begin to describe the quality and attention to detail that has been put into this kit. Beginning at the headers through the downpipe and continuing on to the discharge plumbing, not one component of this project has been compromised. He has put a great deal of effort in packaging this kit to fit tightly in the engine bay without any plumbing looking out of place. Basically you can just gawk over and under the engine bay for hours on end!

I received a call from an extremely excited person (Jason ) on Saturday morning to let me know the car was up and running. Amazing how passionate Jason is about building Vipers! Monday afternoon we strapped the Viper on the dyno. After a few pulls, we seemed to have a boost control problem where the boost would bleed off as rpms climbed. I couldn't believe that the car was performing as well as it was considering it had been operational for a matter of minutes and the largest problem we were encountering is a boost bleeding issue! We called it a day after a couple of hours of testing. The next day, Jason figured out the problem and it turned out that re-routing 1 vacuum line fixed the problem! A prototype twin turbo Viper operational for less than a day and the largest problem encountered was with 1 vacuum line!

Now on to the good stuff and hopefully my memory serves me correctly! With an extremely rough tune (11:1 AFR/Reduced timing/93 octane pump gas), we managed to pull 725rwhp/825rwtq @ 11psi. This is on a completely stock engine(No rockers, cam, or headwork) and through a set of Random Tech catalytic converters. This car has absolutely no turbo lag to speak of and the torque curve is incredible! I was trying to watch the boost gauge and by the time my eyes corrected to the gauge, the dyno pull was over! At no point is the torque number below 700ft-lbs.

I want to thank Jason for building this car far beyond my expectations, especially on the 2nd day of testing! I can't wait to drive this car on the street once Jason buttons everything up and finishes testing and tuning.

 

[1TONY1]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Nice. You can bet Jason will fine tune that thing and the numbers will get better !! Did I mention you **** !!

 

[Gerald]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

sweeeeeeet

 

[96 GTS]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

It will only get better. After Jason gets everything done, be sure to have him take your car to the strip to see what numbers it can produce.

 

[Yellow Fever]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Congratulations Sal !! I'm on the list for Heffner's 1000 SCI pkg next month..Now you have me thinking that I might want to switch that to Jason's TT PKg..
I'm sure it would push out my completion date, but then again good things come to those who wait.

Please keep us posted !

Cheers

JEff

 

[GaryA]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

It definitely makes you think about twin turbos when you see that incredible torque curve! Jason had to rub it in when he superimposed the TT curve over my SC curve--and he's not even finished tuning it. I think it was making around 700 rwtq at 3000 rpm (this was on the first day of tuning!).

Oh yeah, and it really is a work of art, but I don't think Jason will be posting pics of it any time soon!

 

[Anthony - 98 GTS]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Congrats, Jason does great work!!!

Now lets see some pics!!!!!

 

[ronviper]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

SALP, congrats i have always been a turbo person from owning SUPRAS TO BUICK GN'S. However why not a single turbo it seems it would be less cost and make the same power, with 488 cubic inch turbo lag is a non issue. Presently i have a GN stage1 4.1 with a PTE 88 turbo, 3800 stall the car is just bad. What fuel management system are you running, compression ratio and will you be able to run more boost?

 

[Viper TT]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

We're already planning an MIR track rental!

Tony: I have no doubt it will get better! I know I ****, but this sucker can't seem get this smile off his face!! So I'm ok with it!

Jeff: You can't go wrong either way!

Gary: The turbo devil is sitting on your left shoulder, isn't it? BTW, where were you on Tuesday? It was a joyous day at the Heffner Power Plant!

Ron: I am also an diehard turbo fan! Hence my other toy! I honestly believe packaging a large single turbo in a Viper would not turn out well. We are currently using a SplitSecond piggyback system, but anxiously awaiting the AEM EMS (which I've had great success with in my Supra). The compression ratio on a factory engine is 9.6:1. Of course more boost will follow! (Remember I'm also a Supra guy!)

 

[MannyC]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Guys, I have a question. If you are not going to be 1/4 mile tracking the car, is the TT really that much better than the 1000 SC package that Jason is putting out? I ask because at 1000 HP or 850 at the rear wheels or whatever it comes out to, aren't you already spinning tires in 3rd gear and probably chirping them in 4th? So unless you are racing up to near 200 MPH, why?

I would love to get a Turbo, but I started thinking about the power I am going to have already and whether the extra cost of a Turbo is worth it. I know you can tune boost for to change on the fly at different RPM's and in different gears, and I can see that being a huge advantage, but other than that, for a street race (to whoop up on bikes) isn't 850 RWHP whether from a SC or a TT going to feel nearly the same since traction is traction?

I would love to hear your comments on all of this. My next Viper will be a Turbo, no doubt. Damn, I better start shopping for one. HA!

Manny

 

[ronviper]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

SALP, the FAST system works great for my buick i don't know whether it would accommodate a V10. Lance Ward at FAST is great to work with but i am sure whatever system you and Jason go with for tuning will do the job.

 

[beckertb]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Manny,

IMO, the biggest advantage of the turbo is that boost will be available from much lower in the RPM. With the centrifugal design as on my Heffner car, full boost isn't there until 4000 +/- RPM, but with many of the newer turbos (ball-bearing, more efficient impellers, etc), they will spool up more quickly and hence deliver higher HP and TQ numbers and essentially shift the power curve to the left while maintaining the high HP numbers for dyno bragging rights. Will it translate to better ETs, trap speeds? Hard to say. Clearly traction is the limiting factor for most of us.

Best regards,

Ben

 

[Moundir]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

congrats sounds like a beast. Gotta love the tq that the turbos make How much boost do you think you can on that sucker?? I'd love to see 20+ lbs on race gas

 

[Torquemonster]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

congrats sounds like a beast. Gotta love the tq that the turbos make How much boost do you think you can on that sucker?? I'd love to see 20+ lbs on race gas

Jason's TT package is already making over 400rwhp by 3000rpm -that is wild on a stock engine otherwise!!

You want to run 20lb Mike?

Well - firstly - its CFM flow more than the boost that counts - but say you run a TT Viper with big turbos set up to flow high CFM at 20lb boost. On a built motor - I'd give you less than 10 seconds to live at WOT on the street There are limits - and that is past them for road useability at WOT.. nice in theory though!

 

[MannyC]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Manny,

IMO, the biggest advantage of the turbo is that boost will be available from much lower in the RPM. With the centrifugal design as on my Heffner car, full boost isn't there until 4000 +/- RPM, but with many of the newer turbos (ball-bearing, more efficient impellers, etc), they will spool up more quickly and hence deliver higher HP and TQ numbers and essentially shift the power curve to the left while maintaining the high HP numbers for dyno bragging rights. Will it translate to better ETs, trap speeds? Hard to say. Clearly traction is the limiting factor for most of us.

Best regards,

Ben

Ok, but if a SC'd car is already spinning tires at low RPM's when you floor the thing, why do you need even more torque and HP at those low RPM levels? If you're going 130MPH and no longer in danger of spinning tires, I can see the extra HP and torque being better, but if you are in a race and you are at those speeds, you will be shifting into high RPM's anyway.

Treynor mentioned that on his S/C'd car, he had so much power that he could spin the wheels at 150 MPH, and thus had to 'detune' the car.

I don't think I would want a turbo for the extra power. I would want a turbo so that I could control the boost levels at various RPM's and at various gears. For example, real low boost in 1st and 2nd gear to minimize wheel spin and more and more boost as I shift gears or get higher in the RPM range. Or the ability to hit a button and turn boost off or turn it way down, like when the roads are wet or if you wanted to road course the car. Those advantages could be huge IMO. Having more HP at lower RPM's when you've got a 1000+ HP car seems counter productive unless you are dragging your car and have huge slicks that can handle the power.

Am I way off base here? I ask because I want my next car to be a Turbo (heck, I would have had my current car a Turbo but I want to wait a while until most issues get worked out and I wanted my car back in December.)

Manny

 

[ronviper]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Superbar the turbo has a wastegate which with the proper controller you can regulate your boost. You do not have to run 12psi all the time however with a s/c the pulley is set therefore you have the same boost level at wide open throttle. I just love the torque and horsepower curve with the turbo at most speeds under 80mph it puts my buick side ways instantly. What a rush, SWEATY PALMS, PALLIATING HEART, AND SCARED LIKE HELLL, but isn't that what we pay for.

 

[Bandit400]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

My primary reason for going the turbo route was to have the flexability to tune the car down or up on the fly. If I want to take a casual ride around town, I dont need to have 850 hp on tap at all times. Now when the guy in the vette pulls up, I can have full power at the push of the button. Also, I don't have to worry about belts slipping or being thrown.

Bandit400

 

[Torquemonster]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Powerful engine management software

Twin Turbos

Innovative features

are all combining to change the face of the ultimate street Viper forever.

There are several tuners offering this and more will cash in on the bandwagon. Some will come and go, some will survive, some will thrive.

As this is a Heffner thread - let me make a prediction....

In the end - as you look for the Heffner TT packages - you'll need to search the front of the pack because that is where he'll be.

Great effort Jason - there's no doubt in my mind about the future and you'll have earned this buddy!

 

[Anthony - 98 GTS]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

A TT Viper will beat any other combination on the street or strip. With the TT you can adjust boost and "de-tune" the car for daily driving. The TT also quiets down the exhaust note and doesn't have the blower whine.

You will see most of the top SC guys going the TT route over the next year.

 

[Drag Racing Consultant]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Sounds like the bar will soon be raised in the TT competition. Lets see there is SVS, Heffner and Henn. I am curious to see the pricing stand points to performance and see who sets the bar for all out power, ET, MPH and top speed. Would be nice to see some really nasty power being made out of a TT package for a reasonable price.

 

[ElDiablo Viper]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

My primary reason for going the turbo route was to have the flexability to tune the car down or up on the fly. If I want to take a casual ride around town, I dont need to have 850 hp on tap at all times. Now when the guy in the vette pulls up, I can have full power at the push of the button. Also, I don't have to worry about belts slipping or being thrown.

Bandit400

When a guy in a Vette pull sup you just turn it down to valet mode LOL

 

[1TONY1]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

You can easily change the boost level on a centrifical car without changing the pulley, but you have to have a capable enough fuel management system to keep the a/f in check. One that either will adjust itself or you would have to manually change the tune up. It will also take a real good fuel management system to be dialing the boost up and down on turbos.

 

[Lee00blacksilverGTS]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Sal, congratulations on the car, I think I remember talking to you at Jasons dyno day last spring and due to our mutual friendship with Jason you trusted me with a little verbal peek into what you two were planning. It sounds like you have exceeded expectations. Great things come to all who plan carefully and develop good ideas with patience, only aiming for perfection. I think that describes both you as an owner and of course Jason as the genius tuner we all know him to be. How good is it when Jasons shop is 10 miles from my house?

 

[pjb]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

sal >> congrats again and definitely want to ck out the set up in person. keep us posted on the MIR thing. thanks for the info on the supra. hopefully i can find a decent quicksilver

 

[ViperJoe]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Whats taking care of all that heat produced? Bigger oil cooler and rad?
Are the turbo bearings water or oil cooled?
Intercooler air to air or other?
Thanks

 

[MannyC]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

You can easily change the boost level on a centrifical car without changing the pulley, but you have to have a capable enough fuel management system to keep the a/f in check. One that either will adjust itself or you would have to manually change the tune up. It will also take a real good fuel management system to be dialing the boost up and down on turbos.

Tony, How much control can a good engine management system give a Supercharged car by adjusting the A/F ? I've been reading a lot about this new AEM system -- would that work? Could something like that be used to reduce power in the first couple of gears so you can mash the accelerator pedal and just take off, the whole time being on the verge of breaking your tires loose?

 

[Gerald]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

You can easily change the boost level on a centrifical car without changing the pulley, but you have to have a capable enough fuel management system to keep the a/f in check. One that either will adjust itself or you would have to manually change the tune up. It will also take a real good fuel management system to be dialing the boost up and down on turbos.

Tony, How much control can a good engine management system give a Supercharged car by adjusting the A/F ? I've been reading a lot about this new AEM system -- would that work? Could something like that be used to reduce power in the first couple of gears so you can mash the accelerator pedal and just take off, the whole time being on the verge of breaking your tires loose?

[hijack]bah!, Manny, trust me.. You'l learn to feather your throttle. YOu'll know how to handle 800+++ rwhp so well within a couple months you'll be able to do a powerslide 180 Degrees across intersections, U turns in the road, etc..
The biggest improvement you can do is get some sticky tires.. With the power you'll be pushing, throw those Michs' in the corner of the garage.[/hijack]

G

 

[MannyC]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

I have heard that supercharged cars are horrible on road course events because the power is not consistent and more importantly, the car heats up very quick.

Would a twin turbo Viper be any different? Could somebody have a 1000 HP beast on the road, but then hit the "track" button which retards turbo boost allowing you to run it on a road course event, or will you still have heating issues?

And is any tuner turbo charging Gen I's ? I am sure some of you know where this is going

Manny

 

[Paolo Castellano]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Powerful engine management software

Twin Turbos

Innovative features

are all combining to change the face of the ultimate street Viper forever.

There are several tuners offering this and more will cash in on the bandwagon. Some will come and go, some will survive, some will thrive.

As this is a Heffner thread - let me make a prediction....

In the end - as you look for the Heffner TT packages - you'll need to search the front of the pack because that is where he'll be.

Great effort Jason - there's no doubt in my mind about the future and you'll have earned this buddy!

As usual, the mighty "Torquemonster" says and does it best! The 1st being the man with all the answers and the second being our beloved V-10!

Sal, Congratulations on your awesome Heffner Twin Turbo System! I have seen the dyno sheet and it looks awesome!

You definitely made the right decision going with my man Heffner!

I have seen your car there for the last little bit. I hope to meet you soon!

Those are some outstanding #'s for a stock motor and a rough tune. Jason is only going to make more power!

To quote the Torquemonster:

"Twin Turbos

Innovative features

are all combining to change the face of the ultimate street Viper forever......"

This is just the beginning of next year's fun to come!

I can't wait to get my Heffner Twin Turbo System! With all the flexibility the turbos offer, the really high HP cars will have to be turboed!

Up to 750 RWHP Vipers will be awesome with the supercharger...... But after this, the ability to have adjustable boost control for calmer everyday driving needs and also ultimate high-end HP considerations will truly make for the ultimate street Viper!

I think it would be interesting to overlay the dyno graph of a similar RWHP blower AND turbo car.

Manny, the thing about the centrifugal blower cars is how the boost, HP and TQ rise with RPM.

Remember that torque is what moves the car period.

Sal's stock Heffner Viper makes 830+ RWTQ around 3500 RPM. This is close to what my car makes at its torque peak........ He is not even running that much boost.

As we all know, it is the area under the torque curve, that makes for the degree of brutality in the acceleration.

If you compare this car at 725 RWHP and 830 RWTQ to a blower car with 725 RWHP and 700-720 RWTQ, which one do you think would be faster?

In a drag race, I would think the turbo car would be faster.

In a every day rolling down the street looking for a race scenario, I think the turbo car would be faster in an average of situations.

As far as a roll-on from around the torque peak of the blower car is concerned, I think the blower car would have the edge because it has the HP climbing throughout the rest of the gear while the torque curve has minimal downward slope.....

It is nice to see there are so many more choices available to hot rod the Viper....

I can't wait for Jason to get his hands on the AEM!, Talk about the "Ultimate Street Viper......."

 

[Paolo Castellano]

Re: Heffner\'s Prototype Twin Turbo Viper GTS

Whats taking care of all that heat produced? Bigger oil cooler and rad?
Are the turbo bearings water or oil cooled?
Intercooler air to air or other?
Thanks

ViperJoe, The turbo bearings are both water cooled and oil cooled. The oil lubricates and is cooled through the oil cooler. The turbos are cooled by the cooling system.

Intercooling is air to air.