Board logo

R1 engine "hesitation" at 5k - 6k RPM
smart51 - 6/12/05 at 06:25 PM

Under hard acceleration in low gear, the revs bounce about a bit around 5 or 6000. Once through that it will run upto the red line.

The roads have been very greasy on the coouple of times I've taken the car to MOT and SVA. The car is on nearly new ordinary road car tyres.

I've also fitted a Barnett clutch plate with coil springs and new EBC standard friction plates (the steel plates look like new).

The car doesn't snake or slide under acceleration in a straight line and it cruises nicely at any engine speed. What is the most likely problem, lack of grip, clutch slip or bad fueling?


mnr laptop - 6/12/05 at 07:47 PM

hi colin

be carefull it will be running that lean you may see a piston have lift off, thats why you have the flatspot, after sva you then fit the dynojet and get it setup and all will be well

cant stress enough though dont run it too much that lean

best regards


marc


progers - 6/12/05 at 09:22 PM

The R1 has a bit of a flat spot around 5-6k normally and this will be made worse by non-ideal fuelling. In a bec with not standard exhaust (and maybe a sausage filter) its likely to be running lean . Get the engine dynojetted and set up correctly on a rolling road and it will be fine. Until then don't cane it too hard you may harm the engine.

Cheers

Paul


smart51 - 6/12/05 at 10:14 PM

OK. The next trip is to SVA which is across the city. 30 and 40 MPH speed limits = 3000 - 4000 RPM. Gently does it.

Where can I get a dynojet kit then? Where in the midlands is good for setting them up?


Paul G - 7/12/05 at 09:55 AM

> Where can I get a dynojet kit then? Where in the midlands is good for setting them up?

Good question - I'll want this doing when I pass my SVA too

Incidentally took my R1 Indy out for a quick (3 mile!) test yesterday.

I felt that flatspot a bit too, but the most worrying thing was the massive clunk everytime I changed gear - is that normal?? It was mint though wheelspinning all the way just got to get used to that power and get the tracking done, cos it wouldnt go in a straight line. Obviously this was all on the private roads around my country estate ;o)

[Edited on 7/12/05 by Paul G]


ChrisGamlin - 7/12/05 at 10:45 AM

They do clunk quite a bit when changing gear but you'll probably soon develop a technique to minimise it. I find if you change like you do in a normal car, i.e. clutch fully down then pull the gear then clutch up again, its very clonky, but if you literally just stab the clutch and pull the gear at the same time, and only partially lift, it makes the change much quicker and much smoother. It seems the more you rush a sequential dog box, the smoother it gets.

[Edited on 7/12/05 by ChrisGamlin]


Paul G - 7/12/05 at 11:28 AM

Ah cheers Chris - I was doing it normal car style, I'd better get some more practice in!


speed8 - 7/12/05 at 12:13 PM

When you're pressing on just upshift clutchless.
Bit of light pressure on the gearstick, lift off pedal, in pops next gear, foot to floor again. Very smooth on the bike, would imagine it would be the same on the car.


progers - 7/12/05 at 04:09 PM

Yep, thats the technique, light pressure on the stick then lift off sharply on the throttle with or without a dab of clutch (depends on how brave you feel) Once you get confident cluthcless changes will be easy, all except that tricky 1->2 change...

Paul


smart51 - 7/12/05 at 04:15 PM

Clutchless gear changes are something for me to practice too.

So where will dynojet / set up the fueling on my R1 engined car?


progers - 7/12/05 at 04:24 PM

I'm talking upshifts here, downshifts are alot trickier. I personally just put the clutch in and bang down the box...

- Paul


progers - 7/12/05 at 04:26 PM

TTS (northampton) used to be the best place, but I heard they have gone bust? If so, you'll probably have to talk to PDQ in slough.

Cheers

Paul


Guinness - 7/12/05 at 04:35 PM

TTS supplied my Dynojet kit about 2 weeks ago. If they have gone to the wall it must have been quite recent?

Fitted my dynojet kit in a couple of hours one evening. (This included getting the carbs off the car, draining the fuel off, draining down the cooling system to get the carb warming system off, getting the choke and throttle linkages off, fitting the actual kit and re-installing it all).

Yet to try it on the road so can't confirm it has solved it (yet). However once the kit is fitted the only adjustments are made to the mixture screws, balancing the carbs and by moving the needles. All of this can be done with the carbs in situ.

Cheers

Mike


smart51 - 9/12/05 at 03:20 PM

TTS haven't replied to my email so I'm just going to have to phone them.

Clutchless upshifts are great. Much smoother and quieter. It still clonks quite a lot when shifting into first.


Coose - 9/12/05 at 04:33 PM

They all do that sir.....


G.Man - 10/12/05 at 06:58 AM

TTS were alive when I left the uk 9 days ago


smart51 - 10/12/05 at 05:30 PM

I went to put my carb needles back in thier original place after moving the circlip up to the top position for SVA. I noticed that there are 5 grooves on the needles, not the 3 that I originally thought. The needles were in the middle groove when I first looked and the "richer" two were hidden by the plastic ring.

If engines run lean in kit cars fitted with foam filters and aftermarket exhausts, what ring should I fit the circlip to?

By movig the needles out, will I cure the flat spot at 6000 RPM problem or will I still need to have it dynojetted? I wouldn't mind leaving that until the summer, unless I'm going to damage my engine.


OX - 10/12/05 at 06:52 PM

to richen it up move the clip closer to the pointy tip.you havnt got to rush out and buy a dynojet kit straight away just raise the needles one space at a time and you'll be ok .
before i fitted my dj on the r1 i just lowered the clip then played with the mixture screws. as a base setting youd be fine with the mixture screws set at 4 turns out . it will probably sound quit lumpy at tick over but you can fine tune this by tweeking the mixture screws untill it smoothes out,,its not easy and doesnt make much difference once your throttles are off the stop but it makes for a sweeter sounding engine and crisper when reving from nothing