GS350BO

That’s an interesting comparison. I’ve never used a throttle commander but I can understand based off of what I hear from folks. So, today I took the car out for a spin to meet some friends up for lunch and I do notice it feeling a little bit peppier. Maybe this could be that the temp is cooler or the TCU adjust its shift logic….who knows I’m just guessing at this point. But can’t ignore the fact the color just looks good right next to the blue manifold.

lobuxracer

iTrader: (2)

The experience will be much like a lightweight flywheel from back in the manual days. Quicker rev build in low gears from less inertia, but zero power "gains" just unleashing a little more of the power that was being used to spin up the heavier damper.

Nunz

That makes a lot of sense, I will say I agree with you that they look fantastic with the blue manifolds... might have to copy you eventually. I just got a set of FIGS LCA Bushings, next will be pulleys, and maybe a Loi tune

GS350BO

Do it! Lol. Yep, I heard good things about the Figs LCA. It’s on my to-do mod list. I definitely recommend you add the HS coils to the list. After install I notice a stronger pull, feels like power delivery is more consistent, and according to research it does add power. I’m going in for a dyno session this coming Monday, curious to see what numbers the car put down with the current mods. This will be my semi-baseline before installing a full exhaust and tune.

RRRacing

iTrader: (1)

really, really curious to see how coils add power. I’m not trying to rain on the parade. I do not know if any NA engine car with a modern coil on plug ignition that legitimately gains power with coils. I’ve run these cars at over 700whp on e85 and tried both coils and ignition boosters like the JMS Powermax and noticed zero power gains, so to say that our OEM ignition coils are so marginal that we would see gains NA is extremely unlikely with tune or without. Only scenario I can see some improvement is with old high mile coils… but then again you can buy new Denso coils on Rockauto for like $35 each.

Rafi

RRRacing

iTrader: (1)

This is true, there are no actual power “gains” on dyno, rotating weight reduction improves accelerator particularly in the lower gears.

results below are our testing (others have independently verified similar results).

GS350BO

@RRRacing I’ll drop this for you, Rafi >>https://www.clublexus.com/forums/rc-...oil-japan.html

I did my research and everything points to it making power and confirmed it myself after install. This product is legit and Japanese don’t do gimmicks lol

RRRacing

iTrader: (1)

yes I was very impressed with the scientific rigor of those tests 😂

GS350BO

Well, I can tell you the fastest FBO IsF are running these coils. And he confirmed the plugs do make a difference in performance. I believe his car ran a 11.2 @120+ mph w/ FBO and a Loi tune.

lobuxracer

iTrader: (2)

And the Loi tune is the reason why. I can just about guarantee you hotter coils will not make more power on the OEM tune. You don't need hotter coils until your cylinder pressures increase. That only happens when you get the AFR closer to ideal. For example - my 1984 FJ1100 came from the factory with a measured 9.2:1 compression ratio (factory claim was 9.5:1, but as is typical mine left the factory with a less than ideal CR). When I set the deck height and milled the head, the measured CR was 11.25:1. The stock ignition would not fire the engine because the compression was way too high for what the OEM box could deliver. So I put in hotter coils and burned up the output transistors in short order. I swapped out the output transistors with higher current units, put in a bigger heat sink, and changed the bias resistors to complement the new transistors, and everything was hunky dory for the most part. The OEM box also had way too much ignition advance for the new compression ratio, so I had to modify the reluctor to reduce full advance from 36 degrees to 29 degrees. I can also assure you 32 degrees was not good. It cost me a set of pistons. I can also tell you there was a 4 mph trap speed difference between the right main jet and one size too rich/one size too lean. The right jet got 126 mph, too rich or too lean got 122 mph.

Plenty of stock FJ1100/1200s ran just fine with the OEM ignition. Mine didn't because the engine was mechanically modified.

So - we know very well Toyota/Lexus/Yamaha factory tunes are quite rich to prevent engine failures while under warranty from bad fuel. They depend on the cats to clean up the exhaust, and they do that well. Once you tighten up the tune, cylinder pressures go up (they have to if you are making more power) and as a result, the OEM coils don't have enough spark to light the fire consistently. If you were to mechanically modify the engine by milling the heads or decking the block (which would definitely be done if you were blueprinting the engine), you might have similar problems depending on where your CR ends up.

Honda is notorious for adequate and no more ignitions from the factory. Every Honda bike engine we modified needed better ignition just to start.

RRRacing

iTrader: (1)

Fastest FBO ran a 11.5 or so on our tune before switching to Loi, but between running 115 and 11.4 he did other things to his car, including our pulley kit, which he himself confirmed improved his 0-60 time by 0.1 sec.

Rafi

RRRacing

iTrader: (1)

Im sorry, but using that logic, what do you think my cylinder pressures are when I run 715whp at 10psi boost on e85???? I have no misfire issues, perfectly smooth torque curve at MUCH higher cylinder pressures. I had a customer bring HKS coils for install, and threw them on a supercharged car just for kicks…. made no difference on the dyno. I also did an experiment a while back on my ISF, running e85 at 10psi, with a JMS Powermax feeding stock coils at 20V peak… no difference.

there is ZERO objective evidence these coils make 1 Hp 😂.

You can’t compare our cylinder pressures to a 4 banger making 15 psi boost and 75-100hp per cylinder… yeah at that point an Subaru EJ or other highly boosted engine might benefit from coils.

And comparing our modern Denso coil on plug ignition to 1984 FJ isn’t relevant.

People need to do a little science here before making grandios claims about magic ignition coils. It would be so easy to do back to back testing of these coils, swapping them on the dyno. And BTW, going to the dyno one week and coming back the next isn’t going to test anything. The variability you get with fuel quality or atmospheric conditions is way more substantial than any improvement a coil can make.

I would absolutely love to be making $$$ selling these coils, if I ever saw a shred of evidence this makes sense.

Rafi

lobuxracer

iTrader: (2)

What do you gap your plugs to for your supercharged application? Is it the factory gap?

E85 isn't gasoline, and heat of vaporization is one of the best features of alcohol fuels because it lowers cylinder pressure by direct cooling better than gasoline. Alcohol works better because you can raise compression higher than you can with gasoline without detonation. That's been known for about 70 years.

Coils are coils. Period. Nothing has changed with how coils work, only how they are charged and discharged. COP has it's own issues with higher operating temperatures, but it eliminates the need for HT wires. Just another trade-off.

Physics hasn't changed. Put a spark plug in a pressure chamber, raise the pressure and it will eventually stop sparking until you put more power to the gap or you close the gap to compensate for not enough power to make an arc.

Close down the gap, and suffer a smaller spark, but a more reliable spark as the pressure increases, or just get a hotter coil and deal with the consequences and service life issues.

The coils are not magic. There are no magic spark plugs. All you need is enough spark to consistently start the fire, and the more pressure you have in the cylinder, the more power you need to jump the same gap. Very basic physics here.

RRRacing

iTrader: (1)

You can get away with stock gap for low to medium boost. Once I start getting to higher levels (up to 10psi) I reduce to 0.032”

Rafi

lobuxracer

iTrader: (2)

But you wouldn't need to do that if you had hotter coils. You're closing the gap 27% to make up for the coils not having enough power to work at higher pressure.