Holeshot? What holeshot?!

[Tasmaniak]

Ok, so quick rundown on the car... RB30 auto NA
Current mods include

Pacemaker headers, 2.25" or is it 2.5"

10.5:1 Compression ratio and something was apparently done to the auto. Its not shift kitted but I was told something about extended bands....All I know is when I punch it it won't shift out of 1st until about 90km/h.

Now, here is my problem, below about 2500rpm (not sure, I have no tacho) this car is gutless! G.U.T.L.E.S.S. Playing around on my mates airstrip the other week we could not even get it to break traction from a stand still. (open diff) Mind you, once I get moving and hit about 25km/h I very quickly start hunting down his Supra (na also) and passed him at about 150. But I just can't get this thing off the line!

Low revs in 2nd is useless and low revs in 3rd has pulling it back to 2nd if I need to get out of the way.

Everything seems to be ok with the engine, no dramas there...just gutless. Could my exhaust be too big? Also, do these engines have a knock sensor? I'm wondering if that is going off like crazy?....that'll slow me down if it's hearing a knock.

Peoples thoughts on this would be appreciated

[Philthy]

If you are in 1st til ~90k's could you have some crazy diff ratio in there? That would kill your acceleration as well

[Jezza]

yeah try the diff and see what ratio it is because that will make a big difference because you should be able to get wheel spin of the line when you plant the acceleration because i can and mine is a open wheeler with a full 2.5" exhaust system

[Tasmaniak]

nope stock diff....I don't need to tell you about the noises coming from the engine at 90k in 1st. It sounds something like the apocolyptic gates of hell opening up....it's gets a little upset. But that is "normal" for this vehicle.

[Tasmaniak]

side note, just crawled under the car and checked the tag on it.. can't read much except for where it said "RATIO 3.45" So....we know the diff is not the issue here. Could it be a trans issue? I don't think so but I am open to ideas here.

[detox_nath83]

you said something about trans.. maybe gear ratios have changed.. 90kms in 1st is not standard..... i would think trans work if it not diff.
thats why doughey on take off and good high end...

[nasty1]

because it seys 345's on tag doesnt mean it has them they prob been changed.do these have kick down cables like vn's?prob adjusted to much if it stays in 1st till 90.

its n/a they are all fairly gutless.

what size exhuast?2.5 inch is as much as i would go.

[Tree cutter]

The torque converter might have been changed so it has a different stall speed. The original torque converters have trouble with the lock up clutch after a while so it might have been replaced. Normally your torque converter wil slip down low in the revs and the lock up clutch engages as you gain speed.

[shiftySLE]

If the auto not changing till 90, get it checked, sounds like the modulator has been adjusted up. Extended bands??? Are you sure it had a cam put through as without a stall and with a cam, thats exactly how the car would drive. Stuff all low revs and more power at high revs. All the lock up convectors do is save fuel when you are cruising.

[Tasmaniak]

ok, the torque convertor makes sense.

Shifty, I raised an eyebrow at the extended bands part. Never bloody heard of it myself.

[Tasmaniak]

so yesterday I slammed the pedal down to get out of the way for an ambo....spewed out massive amounts of black smoke....hmm... Grabbed a narrow band AFM gauge and sure enough...full rich...all the time.Measured the resistance from the AFM....75 Ohms. WTF? Noticed it was also missing the cover to stop people from adjusting it. Cranked it back out to the 500Ohm mark, improved it a little bit but not by much. Did notice that the two wires going into the ECT sensor are a little soft, perhaps internal break? The engine had been running for around 10 minutes, long enough to warm the coolant up enough to trigger the computer, but it was definetly stuck in open loop mode. Doesn't seem to see closed loop mode at all. Although it will hit full rich if it goes WOT, not sure if that it really is full rich or if it's the computer seeing open loop and richening up the mixture? Further invesitgation is required.

[MR 1JZ]

get it on a dyno if you really beleive someone has messed with the mixtures...o2 sensor could also be fubared!

[Tasmaniak]

Dyno won't show me much. What I really need is to get the car onto a 4 Gas Analyser. That will tell me everything. Will be getting a new o2 sensor when the bloody part arrives at work. Going to take it from there. Disconnected the ECT.....no difference, so that tells me plenty also.

Just filled the car up with some crap called PLUS ULP?! Apparently it's a higher ethanol mix but 95RON. Didn't know until afterwards, so I will not be paying attention to the AFM until I suck this tank dry.