I just want to chime in here regarding tuning our cars. We have tested our tune on all model years, and by testing I mean both street and on our in house DynoJet 424x. Our tune has been around for a long time, and I realize there are ISF owners out there wanting to try the latest flavor tune, but let me just say that no other tune had been as well documented as ours in terms of independent dyno results posted on social media, as well as actual 1/4 mile results.

As these cars age, there are definitely variations in the way these cars respond to tuning. Over the years, we have received and conducted compression testing from probably 100 or more ISF's (owners looking to SC and testing their engines before hand). We have seen 150,000 mile cars test 200psi+, and just a few days ago we had a 80,000 2012 ISF test at 180psi. Some cars test as low as 160 or 170psi! Generally speaking, cars that are KCLV challenged tend to be the lower compression cars. That probably has to do with a number of factors and how well the car was maintained over its lifetime (many of which are approaching 13 years. Based on what we see at our shop, I think the number one factor that results in engine damage is the infamous valley plate leak. Many ISF's, through no fault of the owner, are driven long periods of time with the coolant leak. We see this when we replace radiators and see significant amounts of deposits/corrosion in the upper inlet, mostly due to driving with air in the system. Another major factor affecting compression numbers with ISF's is cars being tracked or driven hard in hot temps without auxiliary oil coolers.

It is interesting that RCF v8 is essentially the same engine, but even as RCF's approach 70-80K miles, we simply do not see the kind of compression test or KCLV response variations as we do with ISFs. There are 2 primary reasons for this. One is the large auxiliary oil cooler does not allow oil temps to reach the levels we see in ISFs. Keep in mind, both ISF and RCF have oil squirters under the pistons to cool the pistons and rings. Once the piston/ring reaches a certain temperature, the stock rings, which are gapped per tight OEM specs, will butt and put pressure on the ringlands. Once the rings butt, cylinder scoring and wear can also occur. These issues are exacerbated in the ISF's due to the common valley plate leak... an issue the RCF does not have.

So let me just summarize what I'm trying to say.

(1) For any of our customers who already have our tune and can do basic datalogs with Toyota Techstream (we recommend getting a good cable like the Tactrix Openport 2.0), we are always willing to evaluate those datalogs and optimize the tune if necessary.

(2) If you have a higher mileage ISF that runs a KCLV of 15-19 on a *stock* tune with good 93oct gas, chances are your car will not respond well to tuning. In most cases, I can predict the exact WHP by just seeing the timing datalog. Timing correlates very closely to dyno results. So if your car is untuned and KCLV challenged, it is not likely to respond well to a tune.

(3) Some tuners, borrowing perhaps from their experience with tuning German cars, claim that leaning out the ISF tune makes power. IT DOES NOT. On the contrary, these cars like to run rich and the tune is most stable when the car is running rich.

(4) Regarding the "transmission" tune that keeps the torque converter locked. This is something we are testing, and hopefully will introduce this option later this year, BUT, there is zero objective evidence that keeping the TC fully locked between 6800-7200 improves acceleration the slightest bit. We have had numerous customers run high 11's and low 12's with our tune as-is. The "new" tunes have been around about a year, with virtually no dyno verification of any of the claims, not to mention a lack of 1/4 mile or 100-200 verification that these tunes are any better than our proven tunes.

Rafi