Engine Software

"jean" wrote in news:nnaxe.14017$ snipped-for-privacy@news20.bellglobal.com:

Google Hondata.

don't believe you can do it through the port. when you read about people "chipping" their car, it's because they've had to disassemble their ecu to replace/reprogram the [e]prom that stores the operation map. the 2001 may be different, but i doubt it because no sensible manufacturer would allow anyone to so easily create bogus warranty claims resulting from inept remapping.

there have been a number of threads on slashdot about ecu reprogramming over the years & the consensus seems to be that the manufacturers generally know what they're doing regarding performance. annoying stuff like speed limiting aside. rev limits should not be raised without appropriate mechanical work to ensure sufficient mechanical strength, balance, etc.

if you want a reprogramming project, check out

even v2 is not as sophisticated as the honda ecu, but it allows experimentation if that's your desire. personally, if i wanted to mess with this stuff, i'd do it on something /much/ cheaper than a 2001 si.

jim beam wrote in news:yqOdnZ1kMZnv0FjfRVn- snipped-for-privacy@speakeasy.net:

from what I've read on Hondata's site,they alter the ECU to accept user programming,and provide a port to a PC for it.(VOIDING any warranty) IIRC,the OBD sensors can actually be used to monitor engine performance and record the data after a run,kind of like an on-board dyno setup.

Hondata.com and I have no connection in any form to the company .

wow, their prices are spectacular. as in, /way/ high.

and i'm not sure about their mechanical engineering either:

says honda ecus are mapped to 9k??? revs are usually limited to absolute max of 7k, 8k for the hot dual cams.

something does not compute.

That seems odd to me too - do the VTECs hit 9K? But then I don't understand why people go to such lengths to enable their cars to go faster when every experienced driver can remember at least one time when they wished with all their hearts they were going slower. A strange mania indeed.

Mike

Tks guy !

I think that over 7k the valves are flotting and we loose power at that point.

I notice that the civic si vtec 2001 has a carb instead of injectors , my

1998 had injectors is it a technical regression ?

jean

"Michael Pardee" a écrit dans le message de news: snipped-for-privacy@sed>>> jim beam wrote in news:yqOdnZ1kMZnv0FjfRVn-

which is one reason why we can't just adjust the rev limiter. need to address valve train, cam, timing, balance, & strength of moving parts before high revs "work".

really? you got a link for that? i see no online parts list showing a carb for that model, or indeed any 2001 si in the u.s.

i think the exotics & the s2000 do, but none of the "normal" hondas do. a /lot/ of work goes into getting honda reliability at those revs.

jim beam wrote in news:wbydnY24sK snipped-for-privacy@speakeasy.net:

Some regions of the world have emissions laws that are sufficiently light that carburetors are still viable. It is possible the car in question is one of those.

The only reason we have ubiquitous fuel injection here is because federal emissions limits are far, far too low for even electronically-controlled carburetors to be able to meet.

"Michael Pardee" wrote in news: snipped-for-privacy@sedona.net:

That 8K rev limit is from the manufacturer;the tuners may decide to beef up the valve trains for even higher RPMs,or they may believe that the motors will do that sort of RPMs without mods. I note that professional racing motors do turn much higher RPMs to gain much of their HP. And look at what motorcycle motors spin up to.

jim beam wrote in news:wbydnY24sK snipped-for-privacy@speakeasy.net:

Me may be mistaking the throttle body for a carb. He should look for the fuel rail and the injectors on the intake manifold.

Does any manufacturer use carbs any more? I don't believe so,just due to emissions control alone.

no doubt - motorcycles & F1 are great examples of what's possible. but you can't do that on a stock motor - or at least, not without substantial problems.

stock motors are balanced within a certain range to keep production costs down. if you want high revs, you /have/ to balance much more carefully, and that's expensive. likewise, the valve train needs to be revised - double coil springs, revised cams, etc. likewise, the components that don't get loaded too much at lower rpms get /much/ higher loads just from the speed, namely con rods, cap bolts, the crank, bearings, etc. and so it goes.

bottom line - you /may/ get lucky and have an engine that can tolerate some abuse - statistically, fatigue always has a range of failure probabilities - but that doesn't address the valve spring issues, cam optimization, etc., so just raising the rev limit on a stock ecu & expecting big perfomance is just going to be an exercise in disappointment. within limits, performance is a function of $'s. there's no point in dropping a bunch of $'s on cams & ecu mods if you don't do the bottom end and throw a rod a week later.