I was part of the Kraftwerks group buy and chose the C38-91 option. My car is a stock '06 with TP. I also installed a Mocal 25 row oil cooler. I can only get 91 octane gas locally. The car is a daily driver and does about a half dozen track days per year. I don't street race it.

As people have finished their installs and posted results, I have been surprised that this kit makes about 15 PSI of boost.

Does anyone have experience with a stock S2000 running 15 PSI on 91 octane? If so, how does it work?

 

Carefully...

Hook up with a great and confident tuner. Most wont touch the car over 12psi with 91, doesn’t mean you cant get a safe tune in the right hands however. I would strongly recommend running a water/meth kit to add that safety buffer. Its a really practical solution to poor fuel availability on high boost situations. Use it to run safe, and a proper performing ignition curve for your set up. Nothing crazy. The motor will thank you with that dense cool intake charge.

 

Don't risk it. Not sure how the kraftwerks kit works, but if its anything like a centrifugal supercharger where it only sees peak PSI at the redline, you might be able to get away with it. But i still wouldn't risk my motor on 91oct.

 

For reference, I'm seeing up to 17psi on my -81 kit. Just a friendly reminder, as you may see more than 15 on your -91.

This is only on cool days though, as in low 50's or upper 40's.

 

water meth is always an awesome solution. Just some simple washer fluid is all I did. On my old k20a3 I ran a meth kit on my Jackson supercharger gained almost 30 whp with meth and a smaller pulley. Later on my turbo set up I used it for a safer af mix. :thumbsup:

 

Cant less timing make it safe? Either turn up boost or retard timing for more or less power?

 

Junky, you seem pretty knowledgeable about all this FI stuff. Can you explain to me what the water/meth kit actually does? I'm 08 with a Vortech V3, running just over 10psi, and curious if I would benefit from a water/meth kit. I plan on upgrading my heat exchanger to the SOS race one. Not sure if one has anything to do with the other, but I thought I would ask. Sorry for the noob questions?

 

Its a centrifugal charger, so yes, peak boost at redline. It does help. Much more forgiving on the ignition timing safety window overall.

 

In a nutshell, its a detonation suppressant, much like race fuel.

Your introducing a stand alone high oct fuel Source aka methanol, and or diluting it with water, which helps remove heat and create a denser intake charge, both beneficial in cooling the combustion and suppressing detonation tendency of an otherwise poor quality/low OCT gasoline, or tune with a higher timing advancement for more power.

You can use water meth one of two ways, the idea of increasing the performance, relying on it increase the headroom for a more aggressive tune, or simply to run as an added safety buffer. In the case of the OP, it would be primarily used as a safety feature to allow him to run at this questionable boost level for the low fuel OCT used with a proper normal tune.

Higher boost makes the tuning window smaller from retarding timing to detonating. There is a point where you cant retard timing enough, and too little timing makes the engine run hot and can cause meltdown. Fuel type is the way around this. Just think of water/meth as running a race fuel, but instead of in the tank, its introduced through standalone and programmed fuel management system either controlled by your current EMS Aux, or its own separate programmable controller. You put a tank in the trunk, run the line into a meth injector before the TB as a single port design or multi point in each intake runner depending on the power/safety goal, and thats it. Typical windshield washer fluid is 70/30 water meth ratio. I used this along with bottles of HEET or denatured alcohol from Home Depot to raise the meth % to either a typical 50/50 or I ran a bit heavier on the meth % at times. Ive had a few different set ups over the years and they called for different % and cc injections.

There is quite a few threads on the subject here on s2ki if you guys do some general searches and want to wrap your head around the specifics a bit more. I know ive posted quite a bit in many of them.

 

Thanks Junky. I've been poking around here a bit and will do more. I remember a comment from another thread talking about IAT's and someone said something about water/meth kit lowering IAT's. Does that mean that the water/meth is injected at the TB and the IAT sensor is right there to see it? I'm guessing that this means I will need to have my IAT sensor moved, since right now it's located on the intake tube between the air filter and the blower inlet.

I'm playing connect the dots, trying to get an idea of how all this is supposed to work together. I will check the other threads and keep reading about it.

Thanks.