For all the bhp figures I've been calculating in this thread, I've been using 15% for estimated drivetrain losses. 15% is considered a bare minimum percentage to use for estimating drivetrain losses with an automatic transmission. I've had a chassis dyno operator suggest that with an automatic and high stall torque converters, drivetrain loss percentages are more like 25+%.
The Only 3300 lb. Buick V6 in the 8s using...
- Thread starter Alky V6
- Start date
Welcome!
By registering with us, you'll be able to discuss, share and private message with other members of our community.
- Status
So now your trying to tell us that your 91 is done!! At just over 1000 hp. 25% I like that......
turbobitt
Well-Known Member
- Joined
- Feb 14, 2002
- Messages
- 2,465
I was playing with this Turbo calculator last night for my own car. I was playing with the numbers and used your engine displacement and made a few assumptions.
Squirrel Performance
Target power 1100
BSFC 1.1 for Meth ?
A/F 5.5 ?
VE at peek HP 95%
Redline 7800
Peak power 7000
Max boost 6500
Min boost 3000
Intake temp 190F and 40F
I don't know Meth so the BSFC and A/F may be way off. Using this calculator, the boost required to make this power at 190F is 49 lbs. Now reduce the intake temp to 40F and boost drops to 34 lbs. Don't know the accuracy of this calculator but it clearly shows the effect on charge temps. Based on this, I would say that the cooling effects of meth and turbocharging is greatly underestimated. So, with your intake temps at 90C, I would still bet that the meth injection is taking way more heat out then is realized.
Allan G.
Not only does he have the slowest car on the planet with a 91mm turbo, he will also have the slowest car on the planet that has used up a 91mm turbo. And all that with 224cid!
DonWG is an over-achiever! LOL! :biggrin::biggrin::biggrin:
Maybe you have something worthwhile to add for a change? That would be a shock.
What's your opinion of what's been covered so far? I'd sure like to see an educated responce from you for once.
It's funny how those that want everyone to think they know it all will resort to trolling. What does that really mean?
I think everyone knows what that means. :wink:
I fixed your numbers above in the quote. Start with those. The VE is the gray area, in my opinion. Try playing with that number to reach the target bhp power. I'm sure the sim your playing with is using bhp for power output. Not chassis dyno power output.
Is the sim you're using taking into account the cooling effect of methanol? If not, then you will have to take a guess as to how much the fuel is cooling the intake air temp. The IAT I gave is measured 12" before the throttle body, in the up-pipe. This temperature reading is after the dry liquid intercooler and before fuel is introduced. If your searching for an intake port temperature, I think the 40F you picked is a very good guess. I can't remember exactly what my EAP gave me for an intake port temp, but that is very close.
Something else to keep in mind when playing with simple calculators. Pressure pulse tuning can contribute 2 to 4 psi extra boost, on top of general MAP, at the intake valve. That may be what you're seeing with the 34 psi answer in your sim.
Ok, I'll bite...... I thought that when you selected this turbo, you did so, based on the info the sim gave you, also you've mentioned a few times that your is in the middle of the turbo map. What have you found that changed this ?
turbobitt
Well-Known Member
- Joined
- Feb 14, 2002
- Messages
- 2,465
I still don't agree with the pressure-pulse tunning, or at least the credit you are giving it with regards to cylinder scavaging. However, I do believe pulse tunning of the headers could be very valuable in driving he turbine and enhancing your backpressure ratio. Not much to argue there.
The calculator was a good experiment to show how the one variable, such as charge temp, could have a drastic effect on a given performance level. This is where I think your combination may shine as a result of using meth and probably one of the key reasons you can get the performance from your stated valve sizes. This is a possible solution to your original question.......
Something, I may add, thats unique to meth and couldn't be done with gas.
Allan G.
I don't exactly understand the question. I think you're assuming that when I used the sim to pick the 91mm turbo, that I wasn't aiming for an efficient area of the compressor map?. By the time I had realized how the nitrous was helping me to spool a turbo (the experiences from the T70 and T76), I had come to the conclusion that I could most likely succeed in spooling a 91mm turbo. With spooling a 91mm turbo no longer being a concern, the only consideration left was picking a turbo that would give me the most efficiency throughout the majority of a run down the track. Before I came across the S510 turbo, I had played with other 91mm compressor maps and I will tell you the engine sim went crazy. The sim really did like the 91mm. The difference between the 91 and an 88 was very noticeable. I was determined to go with a 91mm over an 88 if I decided to go big. The problem was always the surge line with the other 91mm compressor maps. I could see by mapping out an operation line that surge was very possible. Then I stumbled across this S510 and when I finally found a S510 comp map and mapped out an operation line, I was hitting the ceiling, jumping up and down. The S510 comp map, compared to all other 91mm comp maps that I had come across up to that point, was like discovering gold. If one takes the time to really study that comp map, it's pretty amazing for a small engine application. The only problem was the choices for turbine side. There weren't many. I was going to have to take a leap of faith that I would be able to spool a gigantic T6 turbine side. I did finally accomplish that goal.
I hope that answers your question. If I misinterpreted your question, try to reword it.
I suppose another take on your question might be that I'm not exactly smack dab in the middle of this 95mm comp map, if it were to be adjusted for the 91mm wheel. After obtaining real world results, which turned out to be better than what the sim was predicting, I did have to adjust the operation line through the comp map. Hence, it is off a little from original predictions. Originally, I was predicting the operation line to start more at the very left edge of the 78% island and work up through the map at a steeper angle. If adjusting to a 91mm in my mind, I was guessing the operation line would be right up through the middle. What changed that was when I had decided to enter a 6.90 index class. I had to drastically detune the car and ended up with 6.80s with only 8 psi boost. I was a little surprised with that. To slow the car down even further to hit that 6.90 index target, I would have had to change out the wastegate spring to a lighter one. That was too much trouble to me and I gave up trying to run in that class.
Anyway, that experience of trying to get the darn car slowed down enough gave me an idea of how much rwhp the car was making at only 8 psi boost. I then mapped that point out on the comp map and it ended up adjusting my original predictions with this turbo. When you adjust for a 91mm wheel, the operation line would be over to the right of the most efficient sections of the map. That's what I'm guessing.
Looking back now, I probably should have gone with the standard S510/95mm. The operation line through that map looks awfully pretty to me.
I have to agree with most of your point. I originally saw that same potential before I even started the project long ago. That's why I went with burning methanol in the first place. But then, all the reading I've done on engine building for methanol fuel stresses the need for larger valves and larger ports, mainly due to the increased amount of fuel that needs to pass through the port and valve, using up port volume that would be needed for air intake too. So, that is still a very grey area, in my mind. Expert engine builders saying I need larger valves and ports for methanol fuel, yet,... here we are trying to explain an extraordinary performance.
On top of that, it's not like I'm running extremely rich mixtures to take better advantage of the cooling effects of methanol. 4.65 for a blown application is on the lean edge. The typical roots blown applications run in the 3s to one for intake charge cooling.
ROFLMAO! How many times must this be stated before you will understand. Your car is a DOG. It's a PIG. It does NOT have "extraordinary performance".
You have a stage motor with aftermarket heads, with nitrous, a giant 91mm turbo, wheely bars, W tires, etc, and you are so slow that you would get smoked my many of the STREET cars in Detroit. I'm completely baffled why you would think anything you did with your simulator did you any good at all. I haven't been so amused by someone patting themselves on the back in a long time!
I suppose then that you must have a comparison you can come up with. What sort of power have you obtained out of a Buick V6 with any Stage I style head using 1.83, 1.5 valves?
BTW, Melony has a car that is much faster than anything you've ever dreamed of building. Since you want to make silly comparisons.
I think the 'play time is over' bell is ringing. Better head back to your classroom, little one.
With every additional post you make, we're all really starting to finally see the intelligence shining through. Keep it up. I'm actually beginning to enjoy your posts.
Speaking of extraordinary performances, you're putting on a beauty. You should be proud of yourself. Everyone here sure is proud of you. (applause in the background)
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
- Messages
- 5,802
What I would take away from a conversation like this is that larger ports and valve would increase hp but they really have no idea how far a certain valve size can go. No one can say, you need a 2.08/1.6 valve to make x amount of power. Certainly no one in their right mind can ever say. You can only go 9.40's with a 1.83/1.5 valve arrangement. Because valve sizes have never been tested in that light. When someone buys a set of heads, they aren't going to buy a set of heads with a small valve. If they can get a 2.05/1.6, they will do it. Your looking to compare hp figures with something that people abandoned years ago. This means all the new turbochargers, new cam shaft designs, new converter tech....none of this has been used with a small valve head to see how far they can go. So if your looking to be the fastest guy with 1.83/1.5 valves I'm sure you have accomplished that. I don't see any sense in anyone else trying to better your numbers just to prove a point.
I really don't expect others to try to best me with small valves. I just think it's surprising how far I've been able to take these heads. Why couldn't someone with stock heads do the same, or close to it? I think I've simply shown some new possibilities.
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
- Messages
- 5,802
Your asking why someone wouldn't put a set of stock heads on a TA block then build a custom turbo system to mount a T6 turbo then use nitrous to spool it? Simple answer would be because it's cheaper and easier to go faster with a set of heads and a smaller turbo using off the shelf pieces. Just look at the time you've spent making this work and it's level of complexity. Watching your video of your staging technique reminds me of watching the space shuttle ready for launch....and I think it has less timers and wiring harnesses. Switches, delay boxes, different fuel systems, an EGR system etc. No one wants the headache when going with well thought out combo doesn't need all the extra gadgets to work.
This is 100% correct and also completely obvious. It's a nice and long way of saying his combination is stupid.
Let me ask you something, Dusty. Why would anyone bother to try and do 8s with a 109 block?
Flyboy. You can chime in with an answer too. Do you think it's Stupid to try doing 8s with a 109 block?
I'm looking forward to this answer. :biggrin:
- Status
Similar threads
