JUN GT Intake Manifold - It's finally here!

[NoHaveMSG]

Originally Posted by 86TOYO2k17

Over the course of a run, what percentage of time are you at WOT above 5k vs below 5k rpm?

Couldn't tell you what percentage, I don't have RPM logs. What does it matter though? There are situations where you may have to leave the car in a higher gear because you can not shift in the sector without loosing time, but a lower gear would put you into the limiter. Not that uncommon to drop down to about 4k rpm on any of the tracks I have been to.

[86TOYO2k17]

Originally Posted by RayRay88

If Aluminum and Metal Intake components were so inferior, they wouldn't be widely used in automotive and motorsports. You know who and or why they use plastic intakes? Low cost and entry level components. You can injection/blow mold a few thousand intakes for the fraction of a cost of a cast or welded manifold.

Probably volume and rate of sales making AI way cheaper unless they know they will sell a certain number of units to make the cost of molding worth it.
A quick google search In fact, this person broke it down pretty well and backs up my hypothesis. https://www.speed-talk.com/forum/vie...22743&start=15

This is probably why aftermarket is usually metal, and oem vehicle manufacturers usually use plastic. It’s the cheapest option for both parties given the circumstances. Aftermarket isn’t using metal because it’s inherently better it’s cheaper for them.

Again heat was the most minuscule of the negative points. But the only one people are fixated on. When given a choice all things equal I’d choose plastic. In the end sure it’s probably negligible and no meaningful difference.

If two products are 100% equal, same cost, weight, performance etc... the only 1 difference was one was 1f hotter. It is still technically worse and can be listed as a negative even if it’s ultimately negligible.

[86TOYO2k17]

Originally Posted by NoHaveMSG

Couldn't tell you what percentage, I don't have RPM logs. What does it matter though? There are situations where you may have to leave the car in a higher gear because you can not shift in the sector without loosing time, but a lower gear would put you into the limiter. Not that uncommon to drop down to about 4k rpm on any of the tracks I have been to.

It matters because that is the entire point. To calculate and decide which option is better. You are probably at or above 5k rpm while WOT 95% of the time. Not sure what’s complicated about that. One option makes more power above 5500 rpm (where you spend the vast majority of your time while WOT) vs one option making more power below 5500rpm.

To overly simplify and dumb it down to the simplest example. If you are at or above 5500 rpm while WOT 51% or more of the time vs being below 5500rpm at WOT then the 2nd option is better. If you are WOT below 5500rpm 51% or more (which makes zero sense) then option 1 is better.

[prandelia]

Originally Posted by nikitopo

I'm not saying it is not worth it, but if someone goes into that route then he has to do it all the way. Sure someone could rev up to 8k with stock (weak) valve springs as much as he likes or needed for some race track, but then he'll just have a ticking bomb.

I would argue otherwise. The whole point is to avoid having to open this engine up because it's a nightmare to pull and work on, compared to say a K24 or something. Nothing is easy to do on it. So you might as well try everything you can within reason before you open it up. That's my plan atleast, as it also requires the least amount of downtime.

Every race car engine is a ticking time bomb. I remember 2 years ago people telling me how shitty the FA20 was, and it will blow up, blah blah. Yes, it will, but when you do the right things, like run proper oil viscosity and pressures, it certainly will go alot farther.

I'll see how it likes going to 8K occasionally, and when it does let go, which it eventually will, I'll replace it with something else, or have a mildly built setup even more prepared for 8K. Will that be next year or 2 years from now, only time will tell.

[why?]

Originally Posted by prandelia

My car is already tuned, so it took maybe 2 hours for tweaking of my current tune. It's just a simple flat hourly fee, pretty cheap actually.

Doesn't more tuning always help?

That torque table could easily make it all worth it.

[NoHaveMSG]

Originally Posted by 86TOYO2k17

It matters because that is the entire point. To calculate and decide which option is better. You are probably at or above 5k rpm while WOT 95% of the time. Not sure what’s complicated about that. One option makes more power above 5500 rpm (where you spend the vast majority of your time while WOT) vs one option making more power below 5500rpm.

To overly simplify and dumb it down to the simplest example. If you are at or above 5500 rpm while WOT 51% or more of the time vs being below 5500rpm at WOT then the 2nd option is better. If you are WOT below 5500rpm 51% or more (which makes zero sense) then option 1 is better.

Why does it have to be WOT? I can't be at 90% throttle at 5800RPM? Stop looking at just HP and look at where the torque is. There is not enough of a difference there to change shifting habits. Track layout and gear spacing are clearly not factors to you.

You clearly have little to no track experience. If I am wrong, please post your data of never driving below 5k RPM under throttle on anything but an oval or drag strip.

[86TOYO2k17]

Originally Posted by NoHaveMSG

Why does it have to be WOT? I can't be at 90% throttle at 5800RPM? Stop looking at just HP and look at where the torque is. There is not enough of a difference there to change shifting habits.

You clearly have little to no track experience. If I am wrong, please post your data of never driving below 5k RPM under throttle on anything but an oval or drag strip.

You clearly aren’t comprehending and understanding this simple basic point. I see exactly what you’re saying and it’s irrelevant to what i am saying.

Because if not at WOT then why would 5hp or 5 ft lbs matter?
If not at WOT modulate throttle to make the power you want.


I specifically said WOT and not on throttle for a reason.

Of course you’ll be on throttle plenty of times below 5k but i highly doubt you are at WOT 51%+ of the time below 5500rpm but if you are then good for you...

I’ll try to dumb this down even further.

If option one makes 155ft lbs mid range but less torque/power 5500+
Option 2 makes 150ft lbs mid range but more torque/power top end 5500+

Under a non WOT scenario, say you would use option 1 at 35% throttle because you want say 90ft lbs in that scenario or option 2 you use 40% throttle to make the same power, You can modulate throttle % to dictate needed power. A 5hp or 5ft lbs max power difference is irrelevant unless at WOT.

Or you scenario 90% at 5800, if you made less power you couldn’t do 93% throttle to make same power? Once at 100% throttle you are at the limit and can’t get more. Below 100% you can modulate more or less throttle to get the power needed for the situation.

For racing applications with 7500rpm redline would you rather have 155ft lbs below 5,500rpm but only 145ft lbs above 5,500rpm, or 150ft lbs both below 5500 and above 5500 both.

[NoHaveMSG]

Originally Posted by 86TOYO2k17

You clearly aren’t comprehending and understanding this simple basic point. I see exactly what you’re saying and it’s irrelevant to what i am saying.

Lol we are not even talking about the same subject at this point.




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[86TOYO2k17]

Originally Posted by NoHaveMSG

Lol we are not even talking about the same subject at this point.




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Agreed. I’m talking about the context of the original post i made that you quoted. And you’re talking about something entirely different.

[RayRay88]

Originally Posted by 86TOYO2k17

Probably volume and rate of sales making AI way cheaper unless they know they will sell a certain number of units to make the cost of molding worth it.
A quick google search In fact, this person broke it down pretty well and backs up my hypothesis. https://www.speed-talk.com/forum/vie...22743&start=15

This is probably why aftermarket is usually metal, and oem vehicle manufacturers usually use plastic. It’s the cheapest option for both parties given the circumstances. Aftermarket isn’t using metal because it’s inherently better it’s cheaper for them.

Again heat was the most minuscule of the negative points. But the only one people are fixated on. When given a choice all things equal I’d choose plastic. In the end sure it’s probably negligible and no meaningful difference.

If two products are 100% equal, same cost, weight, performance etc... the only 1 difference was one was 1f hotter. It is still technically worse and can be listed as a negative even if it’s ultimately negligible.

I think we're almost saying the same thing or one of us is misinterpreting something.

OEM's are doing production in the thousands so yes plastic injection molding will always be cheaper, but you'll also notice as your vehicle price point and performance increase aluminum and cast steel becomes more and more prominent. The site you linked was for small shops/hobby enthusiasts casting their own products for one offs. This wouldn't be feasible for any sort of production run.

I'm still not sold on plastics heat properties. I work with companies who use plastics and advanced materials exclusively in aerospace/automotive/defense/motorsport applications and none of them would pick a plastic application over metal unless cost was an issue. Even then they usually have to work with fillers and our materials suppliers to make sure it can handle whatever application they need it for.

[rice_classic]

I suspect that prandelia will be just fine. The problem with chassis dyno is that when you put in a different final drive and pull in the SAME gear, you will often see a lower power graph due to how they calculate power; but the car would be faster in a straight line in reality because he would be turning more RPM for given wheel speed in a given gear vs the 4.10 diff.

Good info on how gearing affects dyno numbers: http://www.bishopsperformance.com/dynoinfo.htm


The important thing that stands out to me is that this modification keeps him within the legal rule set and at the target WHP range, allows him to utilize another 500rpms if needed without the engine completely falling on its face and the 4.55 FD will literally help him everywhere on track, especially when using 8k rpm.

Without lumpier cams or bigger valves, the cylinder heads can only breathe so much and something like a larger throttle body or fancy intake manifold is only going have to have incremental gains on an NA application without addressing the cyl head.

A lot of sentiment here is that the juice isn't worth the squeeze, which is false, if you're racing and it's in the budget, it's not just worth the squeeze - it's imperative to remain competitive. What's being realized by many is that this modification and class of racing isn't within most of our budgets and therefore unjustifiable. Prandelia is not modifying a street car after all.

[rice_classic]

Also, I think things were put properly in perspective when he said the price of the manifold isn't unreasonable at all when you take into consideration the disposal of $1800 in tires every 6 sessions (hoosiers). I wouldn't be surprised if his annual tire budget is ~$5-10k

prandelia, I've enjoyed watching your races in GLTC and can see why burning some $$$$ to find that "little bit more". it looks like you only need a "little bit more".

Good luck in 2021.

[86TOYO2k17]

Originally Posted by 86TOYO2k17

The 250 shifts the powerband up about 3-400rpm, and should make more power everywhere above 5500 rpm, and hold onto the power slightly longer. Even if short shifting at 7k you should never be under 5k rpm. So for racing scenarios the 250 is the best for NA.

Originally Posted by NoHaveMSG

That is not how the real world works. Maybe, maybe, if all your gearing was perfectly setup for a specific track that had no long section of corner combinations that would prevent you from shifting it could work. Or maybe if you are playing a video game and you have flappy paddles.

Originally Posted by prandelia

My car only sees the track, so their marketing data regarding the lower frequency, and lower RPM vibrations don't have much meaning to me, as the vast majority my RPM's are 5000-7500.

[NoHaveMSG]

Originally Posted by 86TOYO2k17

Lol, not what I was getting at, but I am glad you found something to give you purpose today.