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Forced Induction Turbo, Supercharger, Methanol, Nitrous


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Old 05-29-2019, 05:21 PM   #15
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Originally Posted by Turbo View Post
I'm not sure if that is actually the case, unless we are talking hitting full boost at VERY low RPMs (where there is insufficient oil pressure at the crank/rods) ?


These cars seem to suffer from oiling issues at higher RPMs, not at lower ones.


Given this, an install that gives up some top end for more midrange might be able to yield the same performance while giving better reliability, not worse.
Correct me if I'm wrong, peeps. Oiling issues at high rpm and high heat are bearing issues. High torque at low rpm bends your rods and such. The FA20 needs some major surgery to do 500 HP all day at the track. It also needs major surgery to take a lot of lb/ft at 2500rpm.
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Old 05-30-2019, 12:28 PM   #16
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Originally Posted by jsimon7777 View Post
Correct me if I'm wrong, peeps. Oiling issues at high rpm and high heat are bearing issues. High torque at low rpm bends your rods and such. The FA20 needs some major surgery to do 500 HP all day at the track. It also needs major surgery to take a lot of lb/ft at 2500rpm.

But can we even get enough torque at low rpm to actually do that, running something moderate like 10-12psi of boost?
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Old 05-30-2019, 12:56 PM   #17
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But can we even get enough torque at low rpm to actually do that, running something moderate like 10-12psi of boost?

With stock rods, absolutely. Easily overcome with an EBC and knowledgeable tuner though.
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Old 05-30-2019, 02:08 PM   #18
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With stock rods, absolutely. Easily overcome with an EBC and knowledgeable tuner though.

So can we quantify the trouble area, RPM-wise? Torque-wise? Or boost-wise?


Still having a hard time wrapping my head around this. I'd like to really bump up my torque in the 2,500-4,500 RPM range, but I'm pretty sure I'll still be far below the peak torque many guys are generating who are running higher overall boost levels then what I'm thinking.
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Old 05-30-2019, 03:52 PM   #19
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If you want lots of low-end torque, I suggest you do some bottom end work and get a turbo. Maybe new rods and bolts would be enough. This is a motor meant to dash at 7k, not lope at 2500.
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Old 05-30-2019, 10:02 PM   #20
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Originally Posted by jsimon7777 View Post
If you want lots of low-end torque, I suggest you do some bottom end work and get a turbo. Maybe new rods and bolts would be enough. This is a motor meant to dash at 7k, not lope at 2500.

I'm already boosted. What I'm after, is a bit more low end and lots more midrange in the 4,000-6,000 RPM region.
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Old 05-30-2019, 10:09 PM   #21
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Originally Posted by Turbo View Post
I'm already boosted. What I'm after, is a bit more low end and lots more midrange in the 4,000-6,000 RPM region.
The unequivocal answer to this is to build your engine and then chase low-mid range torque with either a positive displacement supercharger, or a fast spooling turbo.
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Old 05-30-2019, 10:22 PM   #22
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I have full boost at 2300 RPMs, although that's not very nice to the rods, and with a solid heat management strategy, I've had no issues. No BOV/Recirc makes for fantastic transient response and modulation.

Hey Mike- when you say you have "full boost" at 2,300 RPMs how much boost are we talking? Stock bottom end?


Also, do you mind sharing the compressor & turbine wheel size and housing A/R specs for the turbo you're running?
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Old 05-31-2019, 11:52 AM   #23
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So can we quantify the trouble area, RPM-wise? Torque-wise? Or boost-wise?


Still having a hard time wrapping my head around this. I'd like to really bump up my torque in the 2,500-4,500 RPM range, but I'm pretty sure I'll still be far below the peak torque many guys are generating who are running higher overall boost levels then what I'm thinking.

I'd talk to your tuner about that.


For a track car, not sure why you're looking for torque under 3500rpm though. I can't think of any situations where I'm under that rpm on any tracks in Ontario.
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Old 05-31-2019, 07:41 PM   #24
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Originally Posted by Turbo View Post
Hey Mike- when you say you have "full boost" at 2,300 RPMs how much boost are we talking? Stock bottom end?


Also, do you mind sharing the compressor & turbine wheel size and housing A/R specs for the turbo you're running?
Whatever my EBC is commanding. 100% stock bottom end.

I have no idea what the exact specs are; it's the 18G provided with the GReddy T518Z kit.

I don't recommend doing this; you WILL bend rods if you try to make big power that low. This was purely an exercise to see how low in the RPM band we could get the turbo to make full commanded boost, and done with extreme caution and supervision.
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Old 05-31-2019, 10:44 PM   #25
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Originally Posted by wparsons View Post
I'd talk to your tuner about that.


For a track car, not sure why you're looking for torque under 3500rpm though. I can't think of any situations where I'm under that rpm on any tracks in Ontario.

I'm not looking for tons of torque down low, but I'd like the car to pull harder from 4,000 - 6,000RPM and it will be pretty hard to do that without increasing power (and torque as well) below 4,000 too, won't it?


As for why -well- when I'm running at TMP through the 4-5-6 complex I'm bouncing off the rev-limiter in 2nd on a perfect run. If I drive this section in 3rd (perfectly) I'm within a tenth but the slightest of mis-steps and it's easy to lose a half second+ there because I'm down on grunt.

The 5-6-7-8 complex at Grand Bend (where I drive more) is almost identical and presents exactly the same problem.


My thinking is that making these changes will allow me to drive these complexes in 3rd, competitively. Safer for the engine (as I won't be bouncing the limiter) and with the potential to go quite a bit faster as right now I'm running out of RPM not grip.

Last edited by Turbo; 05-31-2019 at 11:07 PM.
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Old 06-01-2019, 12:07 PM   #26
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Originally Posted by Turbo View Post
I'm not looking for tons of torque down low, but I'd like the car to pull harder from 4,000 - 6,000RPM and it will be pretty hard to do that without increasing power (and torque as well) below 4,000 too, won't it?


As for why -well- when I'm running at TMP through the 4-5-6 complex I'm bouncing off the rev-limiter in 2nd on a perfect run. If I drive this section in 3rd (perfectly) I'm within a tenth but the slightest of mis-steps and it's easy to lose a half second+ there because I'm down on grunt.

The 5-6-7-8 complex at Grand Bend (where I drive more) is almost identical and presents exactly the same problem.


My thinking is that making these changes will allow me to drive these complexes in 3rd, competitively. Safer for the engine (as I won't be bouncing the limiter) and with the potential to go quite a bit faster as right now I'm running out of RPM not grip.
A longer differential would solve that without having to swap turbos or build your bottom end.

Also, Mike, aren't you mainly driving at the high end of the revs when you drive hard? Just because you can put strain on the low end doesn't mean you do it much.
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Old 06-01-2019, 02:15 PM   #27
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Originally Posted by Turbo View Post
I'm not looking for tons of torque down low, but I'd like the car to pull harder from 4,000 - 6,000RPM and it will be pretty hard to do that without increasing power (and torque as well) below 4,000 too, won't it?

Not with an EBC, good tuner, and progressive boost. Doesn't have to want full boost right away, it can be scaled in so you're spooling low but not too low to risk the rods.
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Old 06-07-2019, 04:07 PM   #28
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If you can make more boost than you want low down seems as though you should go bigger turbo for more efficiency, less heat, more power and less stress on the engine.
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