224cid BUICK V6 spooling a 91mm Turbo
- Thread starter Alky V6
- Start date
Don, looks like you need to work on the weight transfer. The car is running way to low in the front going down the track, I.E. no weight on the rear tires.... Traction problems you speak of, not the need for a wing.
What was all the smoke at the end of the track?
What was all the smoke at the end of the track?
The front grill is blocked off and I have the front end tied down. Trying to keep air from getting under the front of the car.
Yes, it looks like tire pressure has been the main traction issue. Everyone was suggesting I go higher on the tire pressure. That was an absolute disaster, and was very dangerous. I ended up going lower on the tire pressure, and a dramatic improvement right off the bat. The pressure is currently at 8.75.
They're MT 29.5x10.5-15W stiff sidewall slicks.
The smoke is a crankcase pressurization problem that's floating the rings. I'm adding TOP FUEL size breather capacity before the next time out.
The crankcase pressure was getting high enough to lift the lifter valley cover plate and spray oil from the front sealing area.
I wonder how much hp I'm losing to crankcase pressure?
The crankcase pressure was getting high enough to lift the lifter valley cover plate and spray oil from the front sealing area.
I wonder how much hp I'm losing to crankcase pressure?
Believe it or not, the car is leaving the line with 1 to 1.5 psi boost and the nitrous. Just before the 60 foot mark, the nitrous shuts down with 170-180 kPa boost pressure built up by that point.
The nitrous is activated one second before the transbrake releases. A perfect amount of time to properly work a sportsman tree.
The car leaves the line as a true nitrous car and transitions to a true turbo car by the 60 foot mark.
The nitrous is activated one second before the transbrake releases. A perfect amount of time to properly work a sportsman tree.
The car leaves the line as a true nitrous car and transitions to a true turbo car by the 60 foot mark.
Your not hitting the suspension nearly hard enough IMO off the line.
You need to hit the tires harder and bring ithe boost in almost fully before you even reach the 60 ft mark.
Very good point, and I completely agree with you. The perfect solution would be a turbine housing with a slightly smaller a/r so I could build a little more boost at the line. Since they don't make that housing for the model turbo I'm running, a lower axle ratio would be nice to increase torque for the launch, get me into second gear sooner so that I can ramp up the boost sooner, but the lower axle ratio would greatly limit me on the top end of a 1/4 mile charge with the size tire I'm running. My redline being 7800 rpm.
The best solution, I believe, is to run a wide ratio gearset in the THM400. I've been eye balling the 2.98 gearset by Coan. Anyone hear any news on that gearset?
The lower gearset would increase torque off the line, allow the rpm to ramp up quicker and sooner. Boost being tied to the rpm rise, the map would ramp up quicker and the 1-2 shift would come sooner. I have to level off the boost to 14 psi for the 1-2 shift, so the sooner I get through that shift, the sooner I can allow boost to ramp up to full limit. ETs and mphs will improve. I imagine it would be worth close to a tenth at the 60 foot. That would be around a 1.30 60 foot. The car likes that 60 foot.
It will be more inconsistent (traction) than anything you could possibly imagine going this route. I agree that something needs to be done with the turbo though.
Just my opinion.
Yes, I see your point and I've been weighing the same thing, and you're absolutely right. The type of launch I'm getting now is a perfect sportsman tree bracket racing launch.
Not very showie, and as a matter of fact, a boring looking pass, but the potential for good consistency for bracket style racing is there.
I will be running the 10.5w slick as well with a stiff wall in Sept. Hitting the tire hard is needed for sure, but good job non the less in making this work sportsman style 
. We are going to leave with more boost this year, given the fact we will not be running Radials. Im looking to leave at 13-15#'s minimum with a 3.50 gear.
. We are going to leave with more boost this year, given the fact we will not be running Radials. Im looking to leave at 13-15#'s minimum with a 3.50 gear.I will be running the 10.5w slick as well with a stiff wall in Sept. Hitting the tire hard is needed for sure, but good job non the less in making this work sportsman style
Make sure you share a video of it. Sounds like a fun ride.
The rpm after I finish staging is 3150 rpm at WOT. Timing is 32.Donnie, What kind of rpm , boost , timing numbers do have on the brake , at the hit and the ramp up to 1 second?? At the 60' mark what is your boost and timing and rpm?? Im just curious it may compare to mine. Mike
When the first amber lights, I release the transbrake 'button' and the nitrous activates and takes the rpm up to 4590 rpm. Timing on the nitrous is 15 degrees. The transbrake is still active.
After one second on the nitrous, the transbrake releases.
After another 1.4 seconds, the nitrous shuts down, map is 170-180 kPa. Timing comes back to 32.
Ok I can hear exactly what your doing with the timing in the video by the grunt of the engine. It sounds happy when you start doing the burnout and gets a bit grumpy as it goes , then in the staging process the motor is not real happy until after the 60' mark which is around where the timing is coming back on. My timing is locked with no retard ever!! It likes timing above 32 and will make giant gains with additional timing increases. Im wondering if the 15 degrees of timing is killing your 60' numbers? Are you spraying it with gas or methanol?? Mike BTW if you dont want this discussion on here I can back off!!
BTW if you dont want this discussion on here I can back off!!Hey dont worry Don, I will. Just got to make sure th camera man isnt my brother, since he likes to move it around to much and kills the vid
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