I run exclusively 91 octane on the street. I run 100 octane on the very rare track day for safety (not power) reasons.

Would you guys recommend running a 5 bar or injectors?

Do you think there will be a noticeable difference in the turbo upgrade from K24s to 24/18g given the gas limitation?

 

I think as far as the 5 bar vs. injectors go it really depends on which tuner you're talking to. I'm running a 5 bar and I'm very happy with it. I'm very confident with my tuner and trust his judgment. IMO if you're going to run 100 for safety reasons only and not turn up the boost (i.e., more fuel required) I'd be comfortable running a 5 bar.

 

Did you come from K24s or K16s?

Was there a real difference in accelaration? How about turbo lag?

 

Based on you making 516 hp on K24's and 91, I don't think you will see any big difference on 24/18's on same fuel. Where the 24/18's shine is when you run 100 in them at 1.3. If you had asked that, the answer would have been a definitive "hell yes."

 

$manager: are you running a 5 bar or Injectors?

I just don't see the point of spending all that money just to be fast once in a while on race gas. Are you suggesting that a K24 setup with a 5 bar is already maxing the potential with 91 octane?

 

When I bought my car it had K16s and a flash. Needless to say it was a night and day difference when I upgraded to my K24/18g. I've had my 18gs for six months and it still feels violent to me. Now if I can ever get around to buying some race gas. I can't say what it would be like coming from straight K24s though.

 

you will be fine with a 5bar if you dont have a problem paying the extra money then go the injector route just for peace of mind.

 

I have a 5 bar and stock injectors. And unfortunately for me, there is a station that sells 100 about 2 miles from my house. My car gets 100 octane probably 3/4 of the time and it is my daily driver. I have checked afrs multiple times and I am good at 1.3bar

If you haven't done it, try to get a ride in a 24/18 car with 100. BIG BIG difference from 91/93 octane.

 

You lucky dog! lol There isn't a place in town that sells 100 octane. It looks like I'm going to have to order some. A couple of interesting options are the E85 that Chris has done or alcohol/meth.

 

I have a 100 octane station on my way to/from work. It's $8 per gallon...

My car is not my daily driver, but I simply don't want to make that concession. I just need to know if 24/18g upgrade makes any sense on 91.

I could just go with a 5 BAR and K24s and see how it goes I guess.

 

I would be interested to know as well as I'm in the process of doing the k24/18's with injectors. Being stuck with 91 really hurts performance. I'm considering trying meth injection as its worked very well on other forced induction vehicles I've owned.

 

I have a Citgo near my house which sells 100 oct for $3.79. Cant beat it , cheapest race gas in town.

 

yes and yes.

I would run the 5 bar with the hybrid upgrade for the same reason you run higher octane at the track. to make sure you have optimized your fuel supply. what kills these engines is detonation. either fuel starve the car or run low octane high boost and kaboom.

is it "necessary" maybe not. but for really a few hundred dollars not sure why you havent already dont it.

also the hybrid turbo is flowing more A/F than the none hybrid version so octane to octane it will always produce more power.

remember I am a vascular surgeon not a mechanic so check with your own boys to see what they say, just speaking from a car with the same upgrades and the FPR was considered part of the upgrade to the hybrid turbos.

 

Ari,

Before the 18g's, I had an EVOMS Stage 4 setup with k16/24 turbos (VERY similar to straight k24's). For me, there was a substantial difference between the Stage 4 and the 18g's. The Stage 4 had slightly less lag, but after 4000 RPM, the 18g's take the cake...and that's at 1.0 bar on 93 octane.

Keep in mind, several guys here are running 1.3 bar with 93 octane, so there is room for upping the boost a bit.

If you really want the 18g's to scream, you can pour in some 100+ octane and crank the boost to 1.3+ and let her rip. It really is amazing how much the quality gasoline combined with more boost wakes the car up. It's a night and day difference.

If I were you, I'd try and get a ride in an 18g car around your area. See if the owner will fill up with 91 octane so you can compare with your car.

Good luck!

 

Ari-

DO IT! Let's get together and putt around some time..