Heffner vs. Hennessey Twin Turbo Information
- Thread starter Infantryman
- Start date
Gentlemen,
The fuel system assist I mentioned on the TT/SC cars was the boost a pump. My TT only GT ran 220.1 mph at the mile without a boost a pump and with stock injectors. My car was hampered by having me drive it BUT.....I was staying at the Holiday Inn Express in Beeville, TX and I had eaten three of young Ms. Mullet's cupcakes!! There is no question that Jason was coming off the starting line much faster in the TT/SC Mullet Mobile. I think he had 4 cupcakes.
John.....screw these TT GTs, I want to see a Venom GT at the next Texas Mile!!!! Get one of your buyers to participate and I will guarantee you a HUGE GT Forum cheering section!! I predict 235 MPH. We'll have a special T-shirt made for you!! Make that happen please.
Chip
The fuel system assist I mentioned on the TT/SC cars was the boost a pump. My TT only GT ran 220.1 mph at the mile without a boost a pump and with stock injectors. My car was hampered by having me drive it BUT.....I was staying at the Holiday Inn Express in Beeville, TX and I had eaten three of young Ms. Mullet's cupcakes!! There is no question that Jason was coming off the starting line much faster in the TT/SC Mullet Mobile. I think he had 4 cupcakes.
John.....screw these TT GTs, I want to see a Venom GT at the next Texas Mile!!!! Get one of your buyers to participate and I will guarantee you a HUGE GT Forum cheering section!! I predict 235 MPH. We'll have a special T-shirt made for you!! Make that happen please.
Chip
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BlackICE
GT Owner
From a programming/tuning viewpoint that would be hard to do. Best to have all 16 injectors of the same type and size. That is what the ecu expects to see.
BlackICE
GT Owner
Great you are smarter than I am.
The ECU switches from 8 to 16 injectors around 3500 RPM, it does this by giving a signal to the injector control module to go into 2 injector mode, while doing so it also adjusts the injector duty cycle (to about 1/2) to compensate for the 2 injectors being used. If you run bigger secondary injectors the parameter such low and hi slopes are different. The ECU doesn't have tables for account for this. So you would have to treat both large and small injectors as the same size and lie about in the fuel maps for RPMS above 3500 to compensate. This would be difficult to achieve seamless operation during the transition from 1 to 2 injectors as well as making the tuning math more troublesome.
IMO it would not recommend using different size injectors unless you have a different ECU such as a Motec. Also I doubt that anyone has done so with the stock ECU. Can someone get it to work OK? Yes, depending on your definition of OK. Many tuners don't give a sh*t about operations other than WOT at RPMs above 3500. In that case it can be made to work. If you want OEM type driveability the answer is NO!
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Mullet
FORD GT OWNER
PL510*Jeff
Well-known member
Wonder of wonders - they agree!
Keep the debate going as I have learned a lot about SC/TT, ECU programing and where to find the best cup cakes south of Long Island.
Keep the debate going as I have learned a lot about SC/TT, ECU programing and where to find the best cup cakes south of Long Island.
Hennessey Performance
GT Owner
- Mar 15, 2006
- 767
Hi Chip, no Texas Mile action for the Venom GT until 2012. You will get a chance to go for a ride in one this year and you might even get a t-shirt to go with it....
Outkastscc
Well-known member
- Oct 17, 2007
- 137
After eating one of Ms. Mullet's cupcakes and drinking one lemonade I went faster on my bike at the Texas Mile. The cupcake was purchased on the black market by that point. I think that made it extra special.
Maybe no one cares, since the main objective is HP, but I would love to see pics of both systems installed.
To me...how something looks, as well as how it performs, makes a difference!
Ummm...can't wait to see the replies on that statement. :rofl Seriously though...post some pics guys.
To me...how something looks, as well as how it performs, makes a difference!
Ummm...can't wait to see the replies on that statement. :rofl Seriously though...post some pics guys.
Here is a photo of the engine in my Heffner TT GT. It won't help you make a decision though because the Hennessey TT/SC install looks really bitchin' too. :willy
Chip
Attachments
We originally did the TT upgrades without the blower, but once we figured out how to do it with the blower it makes perfect sense. Same peak power and a ton more torque down low. Durability has been awesome, as Mullet just loves hot lapping the Texas MileMost of the original TT guys we did have switched to the new TT/SC setup. We have done dozens and they are amazing.
I'd like to thank you all for your insights in this thread. Special thanks to Mullet and Dave Golder.
Having decided what I really want the car for, I'm dropping my search for a GTX1 and picking up my GT later this week (as soon as I complete agonizing over whether I want yellow w/black stripes, or white w/blue) then shipping it to Texas for some Hennessey love.
Dave Golder
Member
- Sep 10, 2008
- 15
Venom GT
:biggrin :biggrin :thumbsup :thumbsup :banana :banana
John,
I'm at your disposal. I have a really fast airplane to get me to Texas AND after I go for a ride in your Venom GT you are welcome to try your hand at some 350 MPH+ aerobatics in my Glasair III. It'll be a great day for both of us. Just give me about a weeks notice. I'll write up a review in the Ford GT Forum as well. :cheers
Chip
:biggrin :biggrin :thumbsup :thumbsup :banana :banana
John,
I'm at your disposal. I have a really fast airplane to get me to Texas AND after I go for a ride in your Venom GT you are welcome to try your hand at some 350 MPH+ aerobatics in my Glasair III. It'll be a great day for both of us. Just give me about a weeks notice. I'll write up a review in the Ford GT Forum as well. :cheers
Chip
2112
Blue/white 06'
I know I read that adding a TT to a Whipple did not work out, my question is, do they do a pulley swap on the stock supercharger before adding the TT?
shelbyelite
PERMANENTLY BANNED
- May 10, 2007
- 1
yes, they usually go with a bigger pulley on the stock blower to lower the boost from the blower.
2112
Blue/white 06'
Makes sense. Wouldn't that help with the keyway stress and heat buildup mentioned in earlier posts?