It looks as if he is foot braking it before he breaks into the beams to build the boost. Then bumps it into the beam and the rpms really come up. Maybe he is just good with the pedal and can bring it up on a transbrake without hitting the limiter??

Who knows.

 

my point is you cant just build boost like that (unless there is something else in the equation) with that small cid and that large a turbo just by holding the gas near max rpm...

it just doesnt do it... thats why 2 steps are so popular with us here to make boost...

so i have to assume there is a lot of load on the engine when transbraking and that he is building boost based on that amount of drag (dont understand how there is that much) and the rpm he is holding the pedal to.?

 

The car mentioned above has a fast system on it along with my MSD digital 6. The limiter is set at 4,500rpms through the digital 6, which is hooked to the trans-brake. You can build as much boost as you like on the trans-brake due to it engaging 1st and reverse at the same time witch puts a load on the car. I'll have him jump on here and chime in.

Neal

 

well there ya go....launch rev limiter.

 

JUst so that Mightymouse understands, it's the trans brake that builds boost with a auto car. On a stick car you'll have a two step that builds boost.

 

i got it now.. makes sense completely i just had no idea the auto would put that much drag on the engine while on the transbrake.

 

The original post said that there was no sig of electronics. You cannot hear the car sitting on a rev limiter before he laucnhes. A lot of the stangs sound like guns going off sitting on the limiter too. LOL

 

He loads it up first on the footbrake to build a couple pounds, then bumps into the beams and comes up on the t-brake like PNYKILR said. Not all rpm limiters sound like gunshots either...Anthony's turbo'd Cobra hits against the 2step nice and soft, while my turbo'd GT would sound like the engine was about to fall out, LOL.

And yes, his white car maxes the 1200rwhp dyno fairly easily.

 

Hey guys, this is Anthony Dickson, the owner of the car in question. Let me start by saying that although I dont currently own one, I have owned 2 LT1's, 1 LS1 6spd., and back in the day an IROC and T/A GTA, so dont be hating!!! J/K!! Seriously though, I have read all your post and lets see if I can clear up some of the questions. First: The car does have a two step but... whoever it was that said he couldnt hear it was right. On that day I was NOT using it. Someone said "he must be controling it w/ his foot" This is true, I was. I do currently use the two step, but only to control total launch boost and rpm. Getting any more confusing? What you are seeing is over a year of hardcore testing with different transmissions, torque converters, and F.A.S.T tuning. Also w/ exhaust wheel and housing sizes. Most of what you see is from the FAST tuning. The more timing we put in down low and fuel we take away will determin how fast it spools. My 5 speed car is the exact opposite. We take away timing and add fuel to it so it will spool. In the stick car we actually put in enough fuel down low that combustion is happening in the headers, thus causing the turbo to spool sooner.This is not always true witha stick car but it works for us, alot has to do with cam timing. The problem with the trans brake theary is, Most transmission builders agree that in a car with this kind of power and a converter like mine, every second you are on the trans brake floored, you will put 100 degrees in the transmission. I have personally melted a bunch and can tell you they ignite at around 300 degrees!!! The trick is to concentrate on building a launch tune-up. Alot of guys get carried away trying to be king of the dyno. A peak number doesnt get you down the track faster than a guy who makes a little less but applies power to the track from start to finish. Bottem line in my oppinion? If it has a stick, use a two step aggressively!!! I leave in my Cobra at 5600rpm and I only shift it at 5400rpm! If its an auto and wont spool hard down low? If you have stand alone or the ability to tune fuel and spark, Spen ALOT of time finding what works for your combo. If you can get it even close, the two-step will do the rest.And yes, start footbraking it atleast 5 feet before you pre-stage, its easier on the trans than the trans brake. I should thanks Jimmy from HP Performance for his help with the tune-up, he is a really, really knowledgable person with stand alone. Wish me luck later this month while I go to PHX. to try and win another PSCA Fastest Street Car Shootout. Thanks for listening. ANTHONY DICKSON

 

Thanks for showing up here on LS1tech Anthony. Glad you could shed some light on this for us. I hope to see you and the car at the track soon, my car is almost ready to hit the strip.
Jeremy

 

Mightymouse, Just to clarify about the trans-brake with an auto (based on my experience):
The trans-brake will only allow the RPMs to go as high as the stall converter. Even if you floor the gas, you won't redline, because the stall is always less than redline. A 2-step is not needed unless your car makes too much boosted power at the stall converter RPM to get traction. In that case dial the 2-step low enough so that when you release the trans-brake, the tires won't roast.

If I use the trans-brake, I automatically roast the 26x11.5x15 Hoosier QTP's to high heaven. I'll either have to go to a true drag slick, or hook the 2-step back up again, and try lowering the RPMs just a little. Taller tire is out of the question because I don't have enough gear to get 'em rolling.

Also, on a stick car, the 2-step must be hooked up so that the bypass/blowoff valve is closed while the 2-step is engaged, otherwise it does nothing except control RPM. When I had the 6-speed, the 2-step was not hooked up properly, so it did not build boost off the line, which was the whole reason I got it. Oh well, I'm an auto now.

 

Let me just say WooooFFF. Nice car and a great piece of driving there Anthony. Very educational too on the technique overview.

Rick

 

Awesome post anthony! We need more real hardcore guys on sites like these.

i also have heard of loading up the motor in a stick they way he is saying (lots of fuel and low timing to combust earlier..thereby adding load to the stick car). Since you have DFI, MM, perhaps something new to try??

 

lol ya i am familiar with the gunshots running the dfi 2 step rich creates. nobody watches the runs cuz they all duck under the bleachers. i havent needed THAT much boost off the line YET so leaving around 14.0 is fine with me (and the crowd)

 

Look into the Boost Builder feature that is built into your DFI box. You enable it through the first stage of Nitrous controls -- but you don't have to be injecting nitrous to use it. Program your desired RPM and boost levels, then the DFI modulates the 2-Step to build boost when you mash the throttle before you launch. It also has it's own target air-to-fuel map so you can make it as rich as you like. Works like a charm.

 

Wow thanks for the heads up Anthony! Good luck at the next race.

 

gtp 40, i know this and use it exactly as you stated.. thats what i meant when i posted what i did.

unless you switch to the dual mapping it backfires like a summabitch.