Achieving 750WHP+ Without Port Injection - A Plug and Play Solution for 2020+ Supras

[Rocksandblues]

fwiw i heat soak in VA summers only at 450hp on the track. I can agree it is pretty simple to get relative cheap and easy dyno power out of the b58. Number of different paths.
Keeping the engine healthy and longevity requires some serious $$ to keep these cool and safe.

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[jRuN]

The Wagner manifold is available for purchase again, I think they have maybe 6 or so in stock from what I just saw

 

[Awad]

Update : I am spinning in 4th and I did a 100-200 with stock tires and wheels because transmission does not handle the 32 PSI at all disengaged completely and I have to turn car off and on I will be building transmission but a pull from 4th onto top of 5th I got 5.98 seconds slipping gears

 

[zrk]

Let me clarify that statement. Port injection pretty much has no limitaion to how much power can be made. For us wierd people, something like 600whp is more than enough to go "around" the track. So lets say a car makes 600whp with port injection. Take that car, tune it DI only and I bet it makes more power.

This makes no sense. If the car has fuel, the car has fuel. If trims are in check and lambdas look good, it doesn't matter how you get that fuel into the composition chamber- it's going to compress and go boom when you add spark.

Now, I suppose there is an argument to be made about timing accuracies on when the injectors fire, but PI can be tuned just as finely as DI, if the car isn't pig rich it's going to make exactly the same power.

 

[Thraxbert]

Agree. Power is based on the AFR, CR, displacement, timing, and (distantly relative to the first four) IAT. PI or DI do not change the fundamentals that determine power.

 

[Evolution]

This makes no sense. If the car has fuel, the car has fuel. If trims are in check and lambdas look good, it doesn't matter how you get that fuel into the composition chamber- it's going to compress and go boom when you add spark.

Now, I suppose there is an argument to be made about timing accuracies on when the injectors fire, but PI can be tuned just as finely as DI, if the car isn't pig rich it's going to make exactly the same power.

I know I am just a nobody on the forum and people dont know what I do for a living but I have actually done this test before (not on a Supra). The key word you are missing out on is "efficiency". Why would every car manufacture switch over to DI if there was no reason for it? The answer is not just for emissions and fuel economy.

We build engines for a certain race series (this one is actually kind of boring) and in previous years, they were stuck with PI. Once they got to changing up the rules, DI was able to be run. The PI engines typically dyno at 185-195whp (like I said, boring). By switching over to DI, we were able to get another half point of compression out of them while running more timing. The results were around 220-230whp. The TQ curve was also a lot better. Between the two engines, the heads flowed the same CFM and the cams were exactly the same specs.

Also to note, this was on the same dyno, nearly the same DA (was done a day apart), same car, same tuner and same dyno settings. But then again, who cares about dyno numbers....

 

[Thraxbert]

But compression ratio is set by the piston and cylinder geometry. Changing from PI to DI (or vice versa) on the same car does not and cannot change that relationship. You are correct to say that DI allows for an engine design with higher CR versus an equivalent motor with PI. But keeping the car the same does not give DI any advantage, because there are no changes to the fundamentals that make power. Fuel, air, comp, displacement, and timing all remain the same for X power target commanded.

 

[Evolution]

But compression ratio is set by the piston and cylinder geometry. Changing from PI to DI (or vice versa) on the same car does not and cannot change that relationship. You are correct to say that DI allows for an engine design with higher CR versus an equivalent motor with PI. But keeping the car the same does not give DI any advantage, because there are no changes to the fundamentals that make power. Fuel, air, comp, displacement, and timing all remain the same for X power target commanded.

Remember the key word here - efficiency. DI is more efficient than PI. Can we agree on that? So by adding PI to a car, you are losing efficiency compared to a full DI car. Wouldnt a more efficient setup create more power because, well, its more efficient?

Questions for you. Why can a DI engine run more compression than a PI engine? Why can they be run leaner without melting pistons? Wouldnt a car make more power at stoich than at 11:1 afr? Are these all not benefits of running DI?

My test results were not made because of that half point of compression. That was probably worth 5whp. It was the DI portion, due to being more efficient, that got the extra power. Car was able to be run a full point of AFR leaner while taking more timing all while being at a higher compression. I can do another test with 2 of the same compression engines if you would like but the outcome will be the same.

 

[Awad]

Update : I don’t know if I mentioned but I’ll be posting all data I can Wednesday. Seeing the whole discussion of PI vs DI the main concern is getting all the fuel possible however I do agree about efficiency. And for power Direct injection has the benefit of a cooler air/gas mixture into the cylinder compared to PI and it enables a higher compression ratio which offers higher performance and efficiency. Second, it enables better engine performance at cold starts. Like @Thraxbert said you can’t physically change the compression ratio unless you actually do however because it injects cooler mix of air and fuel this helps with avoiding premature ignition . In racing cooling and efficiency are king I have not upgraded cooling to see the effects it has on the car and upgrading accordingly . I will now start cooling upgrades but that’s aside from the point of this thread . Again I’ll post all data available Wednesday.

 

[EddieNel]

This damn thread has my head spinning. It’s a lot to digest for this new guy.

 

[DarkZupra]

This damn thread has my head spinning. It’s a lot to digest for this new guy.

A lot of people arguing semantics. Wait for the data, compare pricing and ease of install/tuning, and then make a decision. Im waiting to see what happens here as well.

 

[OldHead-MKV-Owner]

 

[KBGT]

And for power Direct injection has the benefit of a cooler air/gas mixture into the cylinder compared to PI and it enables a higher compression ratio which offers higher performance and efficiency. Second, it enables better engine performance at cold starts.

How does DI achieve this claimed benefit of cooler air and gas into the cylinder as compared to PI?

The second claim of better DI engine performance at cold starts vs PI may or may not be true but it does not matter. Why you ask, because even if you run PI on your car you still retain the stock DI. That stock DI system is what supplies fuel to your engine at all times including cold starts. The PI only starts injecting when in boost.

Edit:

 

[zrk]

still retain the stock DI

Yuuupppp and it fucking sucks. If we could delete DI we could run full methanol.

 

[EddieNel]

Yuuupppp and it fucking sucks. If we could delete DI we could run full methanol.

That’s right! I was at Circle K and asked where their methanol pump was located and the clerk was like huh?

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