The motor i plan to get is a GSR OBDI. I dunno if it has knock sensors.

 

you cant judge these things by psi!!!!!!!!!! why do people insist on saying 10psi needs this or i can go past that. it depends on your turbo. 10 psi on a t3/to4e isnt the same as 10 psi on a tdo4h it differes with your setup. i just wanna make that clear. alot of things depend on how much your car can handle. i have a friend running 22psi on a prelude making big power but another with a hatch built gsr running 16psi. making the same power. h23 has more torque but not much power. so your whole setup is the deciding factor.

 

sorry, but in this case the psi is a very important factor. I agree that psi will not mean much in the case of how much your engine can or cannot handle. Hp and torque are a better figure, but when it comes to octane rating, compression is what it's about. Since boost (in psi) changes the effective compression then yes PSI is a valid measurment. Also PSI is pressure. higher pressure creates higher heat,... so fuel is more prone to self combustion(pre detonation, knocking, pinging or whatever you want to call it). So for this type of discussion,... yes PSI is valid.

 

is there gonna be that big of a difference in my turbo hatch with switching from 91 now to 93? Will it run any better?

 

What year do you have? Is it equipped with a knock sensor? If so the ECU will try to advance the timing automatically for most power and you should be able to see a difference. Now this is assuming that your ECU had to induce a lot a retard on the timing to avoid knocking. You can see how there is a limit on the amount of gains you can get from simply increasing octane rating of the fuel. So it depends on your current set up.

Now if you don’t have an ECU with knock sensing capabilities or you have a piggy back(full controller) with timing control then you would benefit from the tune by manually removing the unnecessary timing retard.

It is kind of hard to say if there will be a noticeable gain without knowing your set up, and actually looking at some timing maps and so on. All I can say is I can really tell a difference when I added my water/alcohol injection on my “heater” of a supercharger set at 11 psi. It allowed for a lot of timing advance(actually removal of retard so I just gained back the power that was lost because of that).

 

well i have a 92 civic hatchback....no knock sensor

2.5 inch downpipe
2.25 in full exhaust
megan racing pulley
turbonetics t3
front mount
custom turbo headers
msd ignition coil and cap
9mm spark plug wires
hyper ground kit
ported head


and an adjustable cam gear in the garage waiting for the install...(im just lazy)

 

My b16a1 in my 1990 hatch has a knock sensor. . . . . .obd0. . . ..

 

I had a d16z6 in a coupe at 13psi with a stock cam gear and that ran fine on 93 octane.

 

I've read on other forums how someone would run 17psi on a V6 with 10:1 compression ratio one 91 octane pump gas,.... now that is just nuts. Later on I found out he had gone through about 2 knock sensors during that time. He also mentioned that he would normally run it at 12 psi, but on occasion he got the boost itch. I was surprised that he had just gone through 2 knock sensors and not 2 engines. I haven’t had a problem with my set up, but I have never pushed more than 11 psi with 91 octane and meth/H2O injection above 5 psi on a non-intercooled supercharger on the same V6 engine mentioned above.

From what I have read, on a turbo set up with an intercooler on an engine like ours (D16) at 9.5:1 compression or so, you can run safely run up to 12 psi on 91 without having to worry about detonation and even a little more boost on 93 octane. Add water/methanol injection and you can probably go up to 15 – 17 psi or so. Any more than that and I would start looking into new pistons with lower compression,…. Now keep in mind this is all just taking into account boost, octane rating, and compression ratios and has not considered the true deciding factor of how much power your stock internals can handle or even EGTs whch are also important to keep an eye on. Once you are that high in boost, you might be pushing close to 220 hp which will start pushing the limits of your stock internals. Set up is everything and every car is different so boost alone will not tell you how much power you are making. So as mentioned before to determine how much power your engine can handle disregard boost numbers and go by hp and torque, however keep an eye on boost numbers as you may be limited by the things mentioned above.

 

look into alcohol injection. what it does is u run pump 93 octane gas but when u enter boost it will give u the extra fuel u need. the fuel cell would just add more weight. alcohol injection is in a container like your windsheild washer fluid. go to www.smc.com