Nickleby4

Hi second newbie question. The rev limiter on my MY2000 2ltr seems to cut in at ~8700rpm - I'm running the standard ecu at the moment, and reading it off a motorsport gauge (which may tell a different tale to the stock dash of course).

Is this right? It's loving it at that speed so it will pull further (and I'm told that they hang together at 11K - though I might not try it).

Anyone know the cheapest quickest way to bypass the stock rev limit? Easy enough to fit an aftermarket version I'm thinking.

Thanks in advance.

Billman250

9700 will split the retainers. You are at your limit.

s2000maniac

The power drops off around 8500, so technically there is no point to beyond that. I believe Honda put the Extra 500 Rpms just so you can stay vtec and not fall off when shifting into next gear.

blasphemy101

This. In some cars, extra RPM might be beneficial for keeping the engine in a desired power band, it's not really necessary with an S2000 (particularly an AP1). The gearing is matched very well to the powerband.

Even without a power increase (even a decrease in power), there may be some advantages to a higher rev-limit, but in this case, that's just not possible with the stock valvetrain.

Billman250

You best advice is to know for sure who told you this, and be sure to never follow any of their advice on anything.

9700 retainer splitting
10700 valve to piston contact

Nickleby4

Wow. It's great to have got quite so much interest going on this subject. Especially from all of those people who don't actually know anything. But to the 3 of you who have taken the time to write something useful I am sincerely grateful.

I should perhaps have been clearer, and explained that the engine is no longer in a Honda shell, but is actually in a 1970’s Ford Rally car, with a plan to develop it to see if it is any good for motor sport. (The rules say <2000cc and no forced induction.) It’s becoming clear that all of the Japanese cleverness that makes this a great street engine is pointless in a motor sport engine, so I’ve probably made a mistake. Over here 10K rpm is pretty much assumed with a steel bottom end and some light pistons.

I’ve been trying to make sense of the answers and am coming up with the following:

- Nobody is talking about electronics or software!! I found a strap-on emulator for the standard ECU but it was a lot of money US$1400 I think. I guess it’s not worth having or somebody would be bragging. I can buy a start from scratch ECU for about half that (and I have the rollers, the skills, and a base map, to map it for nothing) so it has to be the way to go. That said there is a Ford and GM engine that will make >270 bhp so the only thing I gain is the Honda box – decision point for the Honda. I don’t have the money to both fix it and campaign it this season so it’s out with the old Pug until next year – which gives me time to think.

- 9700 seems to be the agreed limit on a stock engine – the retainers being the limitation. Curious that nobody is talking about fixing the retainers or changing cam profiles to help them – I assume retainers translates from USA English to UK English directly? We would mean the valve cap retainers.

- 8500 seems to be the opinion point where the power drops off – I’ve not had this on the rollers yet so I don’t know for sure. Mine is a lot lighter (1080Kg / 2380lbs) with 2 of us in it, and is geared for 130Mph at 10Krpm in 6th. At 8400rpm that’s only 109mph which, on gravel in the forests, may be beyond the point when my a**hole shuts the throttle, but on tarmac its hopeless (I’m going to need another final drive for tarmac which is a load of agro). I have to say that it is difficult not to hit the rev limit (believe me in the low gears the tacho moves too quickly to follow) so I’m questioning the reality of this. If it really can’t rev past this then it’s probably time for a cam that works lower down to get the same result but more drivable.

- Actual rev limit on mine. I need to hit the tell tale (should have thought of that sooner – I’ll go and do it today). I’m thinking it’s more like 8K than 8.5 which makes sense with a calibrated tacho. Obviously Honda had no reason to be honest so the OEM fitment is probably somewhat optimistic. It’s basic marketing. We (the OEMs) do this with Speedos too – sorry it’s basic marketing and it looks great to the uninformed.

- 10700. Piston contact. That’s great info to set the hard cut rev limit. 10K gives me 700 in the bag as safety factor (obviously I need to think about the marketing though). Stage 2 is obviously skim the pistons which moves the risks to the valves. It still gives me another 20% though. Definitely worth having if it makes this thing drivable (it’s hard work now), and its another 26mph with the low diff. By the way Billman – you have never been more right – the guy that told me this also sold me the oil pump that’s too small – more marketing I guess. Go figure!!

Regards the (100s) of know nothings that have felt the need to contribute, I can’t help but join in the friendly banter: Psychology 101: Let’s face facts. You joined this group seeking reassurance, from others of similar mind, that the car on the drive is a good decision. That’s because you are insecure (it’s OK we all are – most of us just deal with it, &/or develop relationships with the opposite sex (or not – whatever floats your boat)). Right now you are insulting me, from a position of ignorance, and anonymity, to feel better about being you, because you know more than me. Sorry but I can’t think of another word than inadequate. I’m sure that stings, but until you find the courage to face it, you’ll never have the life that the rest of us take for granted. Time to grow up maybe?

Brandon – really? You take photos of engines? I assume you are single and have time on your hands? And yes I’ve had the gearbox (tranny in gibberish) out twice. Top tip – if the output shaft isn’t perfectly straight (e.g. 0.2mm run out from the accident that wrote off the Honda) it will eat the new taper roller bearing in about 20miles and start whining again. It’s good advice though – for the short circuit stuff we do take gears out that we don’t need – why carry the weight of top and bottom gears if you are never going to use them. By the way. How fast does your Honda theoretically go? I didn’t think about 6th (or weigh it) because I’m going to need it, but I expect I could save 2 or 3 hundred grams by machining it back to a spacer before I even think about the friction of it constantly meshed for no reason. How much does your Honda weigh and just how fast would my car 1100Kg (yes I weighed it) disappear out of sight if you ever found the courage to come out on the stages?

Darcyw – Seriously thank-you. I was 45 last week and don’t like it. “Kid” – fabulous! Thanks again.

NFR_AP2 – We’re all like this in the UK. We think (I was going to say outside the box, but I think I’ll stop at “we think”). Possibly that’s why the USA’s current best selling small car was engineered here (I am one of that engineering team so I’m laughing at you), and maybe why you are driving Japanese engineering. Just a thought, but for your education my everyday runabout runs at 7750rpm as stock – it’s different here.

Thanks again to the clever folks and to the others remember “It’s just friendly banter”.

nissanfanatic

"A guy" sold "an engineer" an oil pump that is too small?

...

I would like to see the rally car you are building (out of genuine interest).

Billman250

I think the reason this thread went in the biased direction is because in your first sentence you stated you were a newbie. It appears you are not, but I can see how some might see it that way. Some have been here a very long time, and can be rough on those that APPEAR to ask a seemingly go-nowhere question.

Retainers in the USA 2.2L are upgraded, so the engine overall can withstand a little more RPM. Not to produce higher rpm as the end result, but to prevent destruction in the event of a mechanical over rev (driver induced)

One of the common known rev limits of the F20C is piston speed. Perhaps this would be a viable starting point to consider higher RPM operation.

Nickleby4

Nissan Fanatic. "Quote: ""A guy" sold "an engineer" an oil pump that is too small?""

Ouch! Today I guess I probably deserved that! You are right and I was going to say it doesn't help to hear it. Makes me laugh though so thanks for that.

It's probably worth pointing out that there is a dry sump kit for sale that isn't big enough in my opinion. The "guy" selling it probably doesn't know, is very plausible, and I'm not going to name names (because of the slander laws). Buyer beware!

Maybe when I've finsished looking at the details I'll publish my conclusions. Important to add to the knowledge base I guess.

Billman. Once again thanks for the input. It's clear that I need to do a great deal of thinking (and spending - which will be the delay this side of xmas). I will of course think more carefully about how I phrase my posts in future.

Thanks to both.

chris_barry

If your problem is running out of rpm at vmax, increasing the rev limiter and buzzing the engine much harder is not the best solution. When you increase RPM the chance of a failure goes up significantly, things like synchros start to complain/shatter and you start to look at rebuild cycles measured in hours. Developing power at these high rpm is also a challenge. I circuit race my F20C and geared my car up from 13" to 15" rear wheels. This actually improved my lap times as on the 13" wheels the engine was running up close to the red line where the power was dropping off. Lowering the rpm a little put the engine back into stronger torque. The standard ratios had me either buzzing too hard, or a gear too tall at our local circuits. Increasing the final drive brought everything back into line.

What type of car do you have. Look at a speedway engineering or Winters differential. they have live axle and IRS units and have an easily accessable drop gear in the rear so you can change ratios quickly just be swapping out a pair of gears. The cost of blowing up an 10,000rpm build will be much more than a new final drive.