I run 94 octane exclusively, my timing is 14 degrees btdc, spark plugs gapped at .030" and running about 6.5 psi. Oh, and the temperature has been below freezing. Lately I've been getting slight detonation around 7000+ rpm in 2nd gear. Before it was only sometimes at the top of 3rd and 4th. It's really pissing me off! It doesn't happen all the time, though. The car runs so inconsistently. Sometimes the power is really impressive, then other times it seems slow. I'm going to install a Walbro 255 this weekend. Do you think this will help?

 

help

 

can i ask why cold weather would cause detonation?
thanks

 

because colder air is more dense than warmer air. therefore more air gets into the combustion chamber, but it is still the same amount of fuel as before it was cold outside. so it detonates. not enuf fuel for the increased amount of air. can anyone explain it better please? hopefully that helped a lil.

 

have you done anything for your fuel system?

 

something isint right cause the greddy bluebox will be disgustingly rich. cold air shouldnt lean it out that bad.

not sure...

 

hmm but isnt the purpose of a intercooler too cool air, because hot air would cause detonation etc????????? otherwise if your theory is right, then a intercooler would harm a turbo setup, not help it..and youd WANT heat too get into yer intake pipe..

 

Nothing has been done to the fuel system other than the 310 injectors and the blue box. I've heard of other people having the same problem, but it seems to me it was at the top of 3rd and 4th. Someone mentioned that the car runs more lean in cold weather, but I don't know why.

 

Correct, the purpose of an intercooler is to cool the intake air. This serves to pack more oxygen into the cylinders and allows you to add more fuel and ultimately make more power. Heat is absolutely the enemy of a turbo car. Hot air is much less dense than cool air, offering less available oxygen for combustion and hot air is more prone to cause detonation than cold air. The problems arise when the intake charge gets colder than the engine management was designed to accomidate. I don't know how complex the greddy blue box is, but it seems to me that to accomplish proper fueling it would have to be tuned at a relatively consitent temperature and then have a way to monitor intake air temps and alter fueling accordingly. BTW when I say tuned I mean by greddy in the design of the system.

Back to the topic. Do you have a way of monitoring air/fuel ratios during the time that you are detonating? Like falcon said, it seems that on all of the dyno plots that I have seen the greddy blue box makes the car run very rich. Do you have a fuel pressure gauge and fpr? Maybe you could adjust the fuel pressure up some and see if it helps.

 

I have an Apexi turbo timer which has a setting to show A/F ratios. I haven't paid that much attention to it in a while. I don't know how accurate it is, but it has to be better than one of those Autometer light shows. I remember it showed rich under full throttle, though. Somewhere in the 10/1 range. I'll check it again.

Like I said, this weekend I'll be installing a Walbro 255. I figure it can't hurt. I will also be drilling my stock FPR using a Dremel and a 1/32" drill bit according to the Endyne instructions.

One strange thing I've noticed about my car is that it sometimes pulls harder under part throttle.

 

Wow, sounds like some probs I used to have, the inconsistent power, more power at part throttle. But I don't think it's the same reason as yours. Somehow my ignition timing was retarded all the way, and once I put on the b16a2 ECU, the car got slower from 4-5k rpm's WOT. Is your ignition timing advanced? Also, my fuel pressure was way too high then (due to Walbro hi pressure 255, got an FPR and lowered fuel pressure). Maybe running rich with the blue box causes inconsistencies and it does cause the car to run really rich under boost and WOT. But that still doesn't explain the knocking.


[Modified by swrdply400mrelay, 6:30 AM 12/12/2002]

 

I didn't think that the Walbro 255lph HP actually raised pressure, and is almost identical to the regular 255, but flows more efficiently at high pressures. Are you talking about the running rich at idle problem? I'm going to be ghetto and drill my stock FPR and see how that works out, instead of getting the adjustable FPR. Should be interesting!

I'm thinking about getting a MSD "Boost Timing Master." It would allow me to run stock, or maybe even advanced timing before boost, then retard the timing 1-3 degrees per pound of boost using an adjustable **** inside the car.

 

I had the same problem, in 3rd after 7k too. It went away for some reason, but it sounded like little "ticks" or sand hitting my windshield. By the way, I have the same setup as you do, Stock motor,walbro 255lph, NGK 1 degree colder, and the Blue Box. Im getting Hondata installed so no more of these gay problems. Have any CEL's lately? Ive had 1, 71, 72, 73, 74, 13 ....

 

Hondata You're so lucky! I can't afford it, yet maybe I should get it before my motor is destroyed by detonation. I never get any CELs. When I first had the kit installed without the intercooler, I got 13 a few times but have been lucky otherwise.

 

Yup, I was running rich at idle. I know it shouldn't runner richer but it did. I found some other people with the same problem, that's how I knew it was the fuel pump. Otherwise I'd still be here confused as hell.

I say save up for a Hondata, OBDI ECU, and injectors. That's what I'm doing...

 

The fuel pump will help. No doubt. I don't know if it will cure your problems but it will help. Also try retarding your base timing some untill the ping goes away.

Are you experiencing any boost creep? That would cause it too.

 

I called Greddy about it and one of the techs asked me if it was above 7000 rpms when I told him the car was detonating. So they're aware of this problem. He said it's normal because of the high compression engine and that the stock fuel pump contributes to the problem. He also mentioned getting a regulator in addition to the fuel pump and increasing the fuel pressure a little, and that I shouldn't retard the timing more than 2 degrees. I'm already 2 degrees retarded, so hopefully the fuel pump will work.

After I installed an MBC, the boost will spike close to 7.5, then settle down to 6.5. I put the MBC in for quicker spooling, not so I can crank the boost. Boost creep is something else, right?