Hi people,

I know that this could be answered before, but I also know that you people are great and like to help persons like me.

This is my problem:

I think my car (95 Eclipse RS(420a of course)) it's getting lean near 6k RPM thru redline. I think this because when approaching that area the sound of the engine seems to be different and it feels different in that area too. I feels like it has no power in it. So, I took out the spark plugs and they look a little white over the electrode. My car's compression #s with engine warmed up are: 250 255 265 270. I know that those numbers are pretty high for our engines but it has to be because the head is pretty low and definitely has been milled wrong. The car has the essentials and most basic mods for a daily driver, a CAI, an ebay header (piece of garbage), custom muffler but nothing else. I know you can help me out on this because you people know a lot about our cars.

If you have any positive comments and something helpful, please tell me about it. If not, please don't fill this up with critics or bad comments. Thanks a lot in advance for your help.

Why do you rev the engine that high? There is no power there unless you have a MSnS or AEM EMS or something of that nature. The reason it feels different is because its pulling timing at that rpm. To fix it, don't rev that high because its pointless.

So, you're telling me there's no other fix to this than to go standalone? There has to be some cheap tricks to our cars same as others. Please think about it and help me out.

It's an ecu issue.

Read how to fix it using the search.

Nope, even when I sprayed on the dyno the car lost power about 6k because the ecu pulls timing. Like I said there is no point in reving that high because we don't make power that high anyway. Unless you have the head work or turbo etc. to flow enough air to warrant that high of rpm then its just wear on you motor.

so lets say for example, I am at the drag strip, I am not supposed to rev passed 6k then? then why do people recommend redlining in second when drag racing?

when I am at the track, I shift @ 6800 in first, then red line it in second, and I am done in third... If I have been doing something wrong then ohh well, but I dont think so. Keep in mind I am NA.

I could understand that the engine doesn't make any power after 6k RPM, but why then chrysler put the redline up to 7k and the rev limiter a lil upper??? If I shift at 6k, the engine goes really low so I think it gets you slower. That's what I think.

I think that, without any way to verify it's actually leaning out, you have no idea what it's doing, and so can't provide us enough information to help you.

If you really think its leaning out (which it probably isn't, you don't have any mods that require additional fuel) then buy an adjustable fuel pressure regulator and increase the base fuel pressure a couple of pounds.

Does higher than factory compression in cylinders doesn't require more fuel?

Higher compression wont require more fuel just better tuning. Most people redline thier cars so when they change gears they are already in the power band. If you shift at the end of the power band then the next gear may fall below the powerband and it will be slower.

Originally posted by joelrios1
Does higher than factory compression in cylinders doesn't require more fuel?

Just because the compression test numbers are over 200psi doesn't necessarily mean you're running a greater than 9.6:1 static compression ratio.

Stock cams, stock head, stock intakes, dont make any good power at 6k. Sounds totally normal what you are experiencing. Heck, my stock cammed 4g63 drops off at 5500-6000. On a stock setup, shifting at redline isn't really the best thing to do. If i remember right, the 420a's power band is from 3500-5000 at best, and you want to shift to keep the engine close to the middle/top of the power band. If you shift at redline, you are pretty much going to be right at the top if not out of the power band. I usually shift at different rpm's on each gear im going into, as the trans gear ratios are not the same from gear to gear. If you are N/A, I would shift no later than 5700 to 6k. Even when i went to the track, being boosted, i shifted around 5700. I know I would ride out the last gear i was in till the end of the track, as shifting that close to the end of the 1/4 wouldn't do much of anything. Airflow through the stock cams and intake, just sucks at higher rpm. Just because redline is around 7k, doesn't mean the engine is supposed to make useable power there. I think your engine and fueling are fine.