So now you're going to try to tell me you have the balls to try a S510? No you don't.Ok sorryI should have said S510.
Time to go Stage II!
- Thread starter Alky V6
- Start date
Simple answer, Gene, is no. And if anyone would like to explain to me why they think it should go faster with a smaller turbo, I'm all ears. Please include some science to back up any theories. I'm getting tired of people simply blurting out it's a mismatch without any further thought process to explain why they think so.
What sort of answer are you looking for? VE percentage by RPM? How wide of a RPM picture do you want around the VE peak?
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
Why does science have to come into play here? I can come up with some crazy scientific theory to prove anything but all that matters is how it truly works in the real world by putting power to the pavement.
Here are the facts. If your turbo is so large that a smaller turbo will put more usable power to the tire earlier in the run, the car will run quicker. It's been proven over and over and over. The Mustang I drive has had at least 6 different turbo's on it in the last 3 years. As of right now the g-trim 85mm is faster than anything before it. Including an f-trim 94mm, Y2K 91mm and 47-88mm. The 47-88mm has a smaller compressor wheel and turbine wheel than the Y2K91mm. The reason it's quicker is because it reaches it's full hp level earlier in the run which reduced it's 60' and 330' times. If I left hard enough to bring the 91mm in as early as the 88mm there are traction issues. That is something no simulator or science will tell you. The highest mph is also with the LF85mm. It doesn't make as much boost as the 47-88mm but the backpressure is 10psi lower so the car makes more hp for a given boost level. In this case. Reducing backpressure by 10psi is a larger gain than increasing intake pressure 2psi.
The difference in Don's combo is the nitrous. Without the nitrous his car won't get out of it's own way and would indeed run quicker than the large turbo. But since he has the nitrous assist he can offset the lazy turbo by using the nitrous to get everything moving.
Here are the facts. If your turbo is so large that a smaller turbo will put more usable power to the tire earlier in the run, the car will run quicker. It's been proven over and over and over. The Mustang I drive has had at least 6 different turbo's on it in the last 3 years. As of right now the g-trim 85mm is faster than anything before it. Including an f-trim 94mm, Y2K 91mm and 47-88mm. The 47-88mm has a smaller compressor wheel and turbine wheel than the Y2K91mm. The reason it's quicker is because it reaches it's full hp level earlier in the run which reduced it's 60' and 330' times. If I left hard enough to bring the 91mm in as early as the 88mm there are traction issues. That is something no simulator or science will tell you. The highest mph is also with the LF85mm. It doesn't make as much boost as the 47-88mm but the backpressure is 10psi lower so the car makes more hp for a given boost level. In this case. Reducing backpressure by 10psi is a larger gain than increasing intake pressure 2psi.
The difference in Don's combo is the nitrous. Without the nitrous his car won't get out of it's own way and would indeed run quicker than the large turbo. But since he has the nitrous assist he can offset the lazy turbo by using the nitrous to get everything moving.
Chris Hogeland
TWISTED 6 RACING
- Joined
- May 28, 2006
Dusty Bradford said:
I agree 100%
I agree also.
And to say the sim is unable to show me the problem I may run into with the power not coming in quick enough off the line is dead wrong. You're simply using the wrong sim. I understand the power curve through the launch problem completely, and if anyone has been paying attention to what I've been sharing with the Stage I build, they already know that is a problem that I'm fighting. I think I've even mentioned that problem already in this thread. I also agree that we're not going to know anything for sure until this thing is together and running.
That was a good scientific statement, Dusty. You may think no science was involved in your statement, but I hate to tell you, there was some scientific thought and applied application going on there.
And to say the sim is unable to show me the problem I may run into with the power not coming in quick enough off the line is dead wrong. You're simply using the wrong sim. I understand the power curve through the launch problem completely, and if anyone has been paying attention to what I've been sharing with the Stage I build, they already know that is a problem that I'm fighting. I think I've even mentioned that problem already in this thread. I also agree that we're not going to know anything for sure until this thing is together and running.
That was a good scientific statement, Dusty. You may think no science was involved in your statement, but I hate to tell you, there was some scientific thought and applied application going on there.
Here's a reply to GNDriven's question.
The whole time that I've been calculating with this Stage II build, I've been using a 65% figure for the intercooler efficiency. Just for the heck of it, I decided to make a run on the sim using an intercooler eff % of 95. The result was very interesting. Below are the resulting graphs using 65% and 95%. The 65% is first.
The red trace line is your VE line, GNDriven.
The whole time that I've been calculating with this Stage II build, I've been using a 65% figure for the intercooler efficiency. Just for the heck of it, I decided to make a run on the sim using an intercooler eff % of 95. The result was very interesting. Below are the resulting graphs using 65% and 95%. The 65% is first.
The red trace line is your VE line, GNDriven.
The graph that was run using 95% intercooler efficiency resulted in some BMEP numbers that are pretty wild. Most likely I'll be shying away from that tuneup.
And yes, it broke above 1,625 bhp.
Notice the difference in the boost curve between the two runs. "?"
And yes, it broke above 1,625 bhp.
Notice the difference in the boost curve between the two runs. "?"
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
I assume this was directed at me so let me clarify.
I can tell you that you will not have a problem bringing the power in quick enough. Anyone using nitrous should never experience a problem with this. What the sim can't predict is if that power will actually accelerate the car to it's predicted performance. When you throw in chassis settings it don't matter how quick you can make the power. All that matters is if you can apply it. Now your talking ride height, instant center, tire size, weight bias, front end travel, track conditions just to name a few. All these make a huge difference when going from a 1.22 60' to a 1.14. Anyone can leave on enough boost and rpm to make the power but applying it is totally different.
You're absolutely correct. All the sim can do is show what might be possible, given certain circumstances. It's up to the fellow tuning the chassis to move it from fantasy to reality, or figure out if a parameter input into the sim is just plain unrealistic.
Besides, I don't think I would ever pursue a 1.14 60' with the weight my car is, just for the durability factor alone.
Oh I, see now its about my balls.......
Don't you know? It's always the balls.Oh I, see now its about my balls.......
Now here's what confuses me. You all get down on me because my combination is so complicated.
Here's the deal that you think is too complicated. After fully realizing the potential of my original engine, I pick out ONE turbo that would be oversized for a turbo only configuration. I install a nitrous system, and tune the nitrous system to spool up that ONE oversized turbo. Done. No multiple turbos over the years. Just ONE turbo that I've been able to move from one engine configuration to another.
Most people would simply need a single nozzle nitrous system to spool up most oversized turbos, so what's the big deal? I know. Filling up that nitrous bottle every so often can be a hassle. On a small shot system used for spooling only, a 10 lb. bottle would easily last the whole day of racing. Most likely over 15 runs down the track. With my large shot system, I've gotten as many as 7 runs out of a bottle.
That could be done, but it's a bit more complicated. It would depend on how much smaller the turbo is, and how much nitrous is needed to spool it. If you needed a 200 shot to spool up the turbo, you might not want to inject that same amount on the top end. It may overspeed the turbo. You might need two separate stages. One to spool the turbo and a smaller shot size for the top end.
You'd also be using more nitrous per run, so you'd be changing out and filling bottles more often.
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
You spent how long figuring out how to put enough nitrous through this engine on alky to get it to come up on boost? How much time and testing and re-doing the set-up to get it to work? There are pages and pages of you making this afterburner system and spool-up set-up sound so complicated like your the only one who can figure it out. Now you down play it like it's just as simple as filling a bottle and mashing a button. Which way would you like it??
Most swap turbo's to keep up with class rules. It's just the difference in being a test and tuner vs a class racer. Us class racers have to take a turbo everyone else uses and figure out how to make it leave harder and run faster than the other guy.
lol Yeah, you're right. It took me quite a bit of time learning what I know now. It took me about 3 days to fully map and get another fellas nitrous/methanol/turbo combination going for him, without the help of a chassis dyno, so I did learn quite a bit in all that time. It was time well spent. And you know what? After you go through all the testing of trying this way and that way, it does just end up being rather simple. Just like learning to walk. There's a lot of falling until it becomes second nature.
That's sort of why I share my experiences so that others can learn through my mistakes.
Class racers? I won't even go there. Doesn't interest me. I have never liked others dictating to me what parts or systems I have to use on my car.
Why is there class racing? Follow the money.
I think you missed your calling and should have been a politician.I will explain the best way i can(TSM cars have been high 8,s and 9,1 with stock heads these days let along TSO cars..) Would this be a true statement?
TSM cars weigh more and have a smaller turbo with no bottle or alcohol but go just as fast as you have gone..Im not trying to be mean i just dont understand why you dont see what im trying to point out.
