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The Quest for 275 MPH

Discussion in 'General Viper Discussion' started by FST SNAKE, May 18, 2020.

  1. FST SNAKE

    FST SNAKE VCA Venom Member Venom Member

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    Well the high from 252 MPH is starting to wear off and we all know what the next number should be. I'm looking into what it will take to reach the next logical goal of 275+. Some of the concerns are the tires and which ones should I be using considering the speeds I want to attempt. I have been speaking to some very knowledgeable people regarding this and hopefully we can come up with a solution that we all are comfortable with. I feel like the team is capable of making enough WHP/Torque from the engine to reach the 275+ and the car is gear capable provided the engine is able to push it to those speeds. We will probably make a switch from C16 to E85/E98 considering some of the issues we had last time with temps. As to safety I don't know how much more I can do beyond what we have done already, maybe update the gear I wear and a new HANs, it's about time for that anyway. I feel the car is aero capable of 275 although I might put a very small spoiler on rear to tighten up the back of the car. I would probably have 3 to 4 spoilers made from maybe 1/2" to 1.25" tall so that I can make a few 225 to 250 MPH passes to see how each feels and then bolt on the one that feels best. It does like to dance side to side just a little bit at top speeds and a small amount of downforce could help with that. The nose seems to create enough downforce at speed that the car feels very connected up front. I just need to get the balance right between adding small amount of downforce at the rear and none up front. I want to limit the distance to 1.5 miles max which will help with the IAT issues we had in the past. As before I'm not trying to be the fastest Viper in the half mile, mile or any specified distance, I'm just chasing the top speed at any distance.
     
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  2. newredrt10

    newredrt10 Former VCA National President Administrator

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    I have looked at many of the peoples cars doing speed runs. I have not seen your car run or don't remember it. my concern is the rake these cars are running. If you run a boat or car noise high you will flip backwards some time. like some Vipers have on the drag track. if your frount down force is ok, drop the frount ride height(at speed) 3 degrees lower than the rear ride height(at speed). this will do several things, keep air out from under creating more down force, will permit removal of down force generators reducing drag(increasing speed). find a tire that has a stronger side wall that will not colaps under down force like somany do, but has the rubber for tracsion (maybe nascar tire)
     
  3. FST SNAKE

    FST SNAKE VCA Venom Member Venom Member

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    Thanks for the input, I do rake the car prior to any runs. The front is lowered as much as possible and the rear is typically a few inches higher. I have some data from past runs that we use to make these adjustments. The tires obviously grow in height with the centrifugal forces acting on them and as the speed increases the downforce acting on the car can result in the tires rubbing the wheel wells. We have learned over time what clearances we need to prevent this. As to tires which are the biggest concern I'm looking at Nascar and Formula 1 tires and trying to find a workable solution that will give me some comfort at those speeds.
     
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  4. Viper_199

    Viper_199 Enthusiast

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    I think Bugatti was working with Michelin or someone and had a carbon fiber reinforced tire that could hold up to 300mph
     
  5. randyzimmer

    randyzimmer Enthusiast

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    Why get stability from drag when a vertical fin could be the answer you're looking for.
     
  6. FST SNAKE

    FST SNAKE VCA Venom Member Venom Member

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    Excellent thought, could take the tail wagging out of the car at higher speeds. I will look into that. I am looking into possible time in a wind tunnel and adding vertical fins will be on the list of options to run. I will let u know how it turns out. Thanks
     
  7. DJ'sviper

    DJ'sviper Enthusiast

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    You sound like you really know what you are doing. Don't push to hard that we don't hear from you again. Work your way up and God be with you.
     
  8. FST SNAKE

    FST SNAKE VCA Venom Member Venom Member

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    Thank you, I want the 275 but I'm also not afraid to lift if that's what the situation requires. Besides the little bit of tail wagging it's a very stable car, but of course every mph gets it closer to the edge of that. I will take great care to make sure it's a safe run.
     
  9. FST SNAKE

    FST SNAKE VCA Venom Member Venom Member

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    Hey everyone, been a while since I've discussed the plans for the next attempt at a big speed. We are back on the car making changes and prepping it for the effort to break 275+ but honestly any speed faster than the 252 MPH run gives us more data to work with. We have the tires/wheel combination worked out and the new transmission will arrive soon. In addition to that we are making the obvious changes to bump the WHP/torque to a level to allow for this. The team is also making some additional safety improvements which everyone that does any form of racing should be concerned with. I will come back and hopefully be able to provide some pictures and more details on the build. I really appreciate the support from everyone and looking forward to a time when we don't all have to stand 6 feet apart with our masks on. Thanks, David
     
  10. Shaggy

    Shaggy Enthusiast Staff Member Administrator

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    Do you have videos of your 252 mile run?
     
  11. FST SNAKE

    FST SNAKE VCA Venom Member Venom Member

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    This is the link to my run on Johnny Bohmer Proving Grounds YouTube channel which has a lot of videos
     
  12. FST SNAKE

    FST SNAKE VCA Venom Member Venom Member

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    The progress marches onward and I have had to switch to a sequential as I can't find a 6060 or T56 that has the gears I need along with the torque rating required. I'm an old school guy who really wanted to do this with a H pattern but the choices were don't run, run with a sequential or run with an automatic. This is a 6 speed from RTS up in Kannapolis NC, probably some of the best machine work I've seen. The gearing actually allows me at max RPM to top out over 300+ but that isn't going to happen with me driving. My goal is anything over the last run of 252.588 MPH and hopefully 275 if that's possible. Here's a few pictures of the transmission, installation is already in the works. It has a load cell and will be managed by the Pro EFI system to allow for no lift shifts once I leave the line.

    Blucifer Sequential 2.jpg Blucifer Sequential.jpg
     
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  13. FST SNAKE

    FST SNAKE VCA Venom Member Venom Member

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    I had the Greg Good heads off of Blucifer refreshed by Nelson Competition over in Pinellas Park Florida. Kris did a great job, checked everything form pushrods, lifters, rockers, valves and springs etc to make sure it was all in spec. Heads were decked, valve seats cleaned up and everything reassembled and ready to go back on.

    Blucifer Greg Good Heads.jpg

    Blucifer Greg Good Heads 2.jpg
     
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  14. FST SNAKE

    FST SNAKE VCA Venom Member Venom Member

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    Headers had a few small cracks that were repaired by Lakeland Speed and Custom and then Jamie had them recoated. They will be putting heads back on soon and bolting up headers, turbos, etc. It's coming together and we are making sure it's as ready as we can possibly make it for the next run. I'm so looking forward to the moment it's all back assembled and on the dyno for the tuning.
    Blucifer Headers.jpg
     
  15. FST SNAKE

    FST SNAKE VCA Venom Member Venom Member

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    In an effort to make the car a little more aero at the speeds I'm hoping to reach we are making small tweaks to the body, diffuser, etc. This picture shows the fog light covers being made, the metal is rolled/formed to tightly fit up against the bumper. Then a "angled cup" is tig welded to the back and the assembly is bolted in from the backside. I wanted to keep it removeable to allow me to return to the stock look later on. After that it's the diffusers turn for some modifications.

    Blucifer Aero Bumper.jpg
     
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