what gains , and why the jerkyness ?!


N

nelbert

New Member
Joined
May 14, 2008
Messages
10
Hi all I recently purchesed an ek9 after years of admiring them.
I have been a Honda man for a number of years , owning two
crx vt's previous to the ek9. I thought I would never own a car
as exciting as my crx's , but I have to admit the ek9 tops them
in nearly every way!

The car I bought has had a reasonable engine build carried out
consisting of :

skunk 2 stage 2 pro series cams
skunk 2 springs and retainers
skunk 2 valves
bronze valve guides
skunk 2 adjustable cam gears
head skim to suit cams
81.5 mm pistons (I think)
engine ballanced ie. crankshaft
new stem seals , rings etc...

The ecu has been converted to obd1 to accept the Hondata
s200 tthat has been used to map the car.

Heres my questions :

1. With this setup and build what sort of bhp and torque should I be
expecting.

2. 80% of the time the car drives VERY jerky . ie. kangeroo petrol.
The other 20% of the time it drives lovely . What could cause this? After
2500/3000 rpm this isnt the case

3. Somtimes on up-shift v-tec will engage at 6500rpm where as it is usually
at 7000rpm

4. What should be my next worth while modification ie. NEW MANAGEMENT ?
, injectors , fuel pump ???

( I typed in new management in q4 incase this is the cause of my
jerky problem)

The car also throws upa cel light every now and again but simply goes
out after the car is turned off and on again.

Thanks Neil. :nice:
 
take your car to someone who can tune hondata S200 and have them look at the map, it may need a remap. if your still on stock injectors that might be the problem, do you know what clutch you have?
 
Going by the sellers word the clutch is an exedy stage one , and the
flywheel is also exedy , (I have no reason to doubt) fitted when
the engine was rebuilt 12000 miles ago. My last uk crx vt had the same drive
setup but showed none of these symptons - also felt and maby was quicker from 70 mph onwards! ( with a standard engine ) !

Problem is , over here in N.Ireland there is not alot of rr / tuning companies
that work with Hondata that I no of or/and trust to work on the b series
engine.

Stock injectors , fuel rail and fuel pump have been my concern although
the car goes through fuel like there is no tomorrow! The car gives off
condensation at the exaust and has no sign of blue smoke which to me shows a healthy engine at least.
 
I think your issues stem from having an improperly mapped ecu. How many miles do you cover per tank?

Even with all the engine mods, unless you're more or less constantly wide open throttle, you should be able to get more or less the same mileage as a stock EK9 which is generally 260miles or about 400-450kms.

That number varies of course based on your actual commute. It would be nice to be able to look at the .bin file off your S200 though.
 
nelbert said:
1. With this setup and build what sort of bhp and torque should I be
expecting.

2. 80% of the time the car drives VERY jerky . ie. kangeroo petrol.
The other 20% of the time it drives lovely . What could cause this? After
2500/3000 rpm this isnt the case

3. Somtimes on up-shift v-tec will engage at 6500rpm where as it is usually
at 7000rpm

4. What should be my next worth while modification ie. NEW MANAGEMENT ?
, injectors , fuel pump ???

( I typed in new management in q4 incase this is the cause of my
jerky problem)

The car also throws upa cel light every now and again but simply goes
out after the car is turned off and on again.

Thanks Neil. :nice:
Click to expand...


1. Should be around 220+ with Pro 2 cams on a 1.6L

2. Its normal with lumpy cams at low rpm, They only start working after 3000rpm. It is also advised to raise your idle to have it smoother, I assume it is already around 1000rpm+.

3. Thats normal because, theres a high cam switch and low cam switch. Your VTEC kicks in at 7000rpm and then it should switch back to low cams around 1000rpm or more under than your VTEC point. So it should be around 5500-6000rpm when it switches back to low cam.

4. Retune on dyno to see if theres anything wrong with the power curve and AFR then you should know what you'll need then. hmm, maybe a small upgrade to your fuel injectors would benefit especially if your running stock injectors. Just something slightly larger, don't go up to S2000 sized injectors, thats more than you need unless its a 1.8L

I think check light comes on for a few reasons, mainly ECU. Is the S200 hondata a piggyback unit or standalone?
 
No comment on the mapping, but it sounds like the juddering is the Exedy stg1 clutch, I have the same clutch with this problem, people who get in the car think I have poor clutch control, it is VERY annoying :angry2:
 
jugbugz said:
Is the S200 hondata a piggyback unit or standalone?
Click to expand...

its a piggback that runs in conjunction with a p28 or equicalent stock honda ECU. and for what its worth it has been recently discontinued.
 
Generally piggy backs dont work as well as standalones, the Apexi AFC eventually gets overrided by the stock ecu and causes problems.

If your check light comes on and then switches off when you restart the car, then there should be any problems with your engine parts, sensors etc. Most likely the ECU.

Nelbert: Are you experiencing anything else other than jerky? Do you have over-fuelling probs? Check your spark plugs to see if the tips are white, black or brown.

White: running lean
Black: running rich
Brown: normal
 
the hondata is a hybrid system of sorts...it's not true standalone like the AEM nor is it a poop device like a VAFC.

hondata regardless of stages has the ability to adjust rev limit, fuel, timing, vtec control and other useful parameters like the IACV and even disabling the AC at WOT and the primary O2 sensor.

All this is great to the seasoned tuner, but could be a handful for somebody just starting out... if you say the car is juddering below 3000rpm, maybe the map isn't cleaned up there.

That or you have a way more aggressive clutch like a 3 puck stage II Exedy...but even with time like 800kms of break-in, it becomes smoother and much easier to modulate.
 
Thanks for the replys people , great responce to a "newbie" !

Racingangel : Im getting around 180-200 miles to a tank with
50/50 of that being wide open throtle / calm driving!

Jugbugz : Idle seems spot on , sitting when at opperating temp at aprox
1000-1050 rpm. I have checked all 4 plugs and the tips are all WHITE.
Although I definatley think over-fueling may be an issue as the mpg
is poor. Performance isnt what I expect from this build especially onward
from 70 mph. the car is definatly not near 220bhp.

Hatch : Its more kangaroo petrol scnario when the clutch is fully
disengaged . I find myself having to "ride" the clutch to overcome
the jerkyness , at which point the car will pick itself up (rev up making
me look like a plonker) !

I think I will have to bite the bullet and take it to the rr and see what
they come up with although as you guys point out the piggy back , discontinued s200 may be a factor.
 
hmm, white tips are not good. I dont think you have overfuelling probs then, otherwise it'd be black. Your actually running lean. I just recommend a retune by someone who is more of a PRO. Should fix many things.

Do you have stock injectors? Might need to upgrade them. If you use more than 80% MAX flow on your injectors, it'll start fluctuating and make a bad spray pattern. RC engineering is probally one of the best injector available as thats all they do.

So besides other unknown problems you will definitely need;

Retune
and
injectors
 
Whats your location, maybe somebody can recomend a good tuner? With more detail it doesnt sound like the problem I have with the Exedy stg 1.
 
jugbugz said:
hmm, white tips are not good. I dont think you have overfuelling probs then, otherwise it'd be black. Your actually running lean. I just recommend a retune by someone who is more of a PRO. Should fix many things.

Do you have stock injectors? Might need to upgrade them. If you use more than 80% MAX flow on your injectors, it'll start fluctuating and make a bad spray pattern. RC engineering is probally one of the best injector available as thats all they do.

So besides other unknown problems you will definitely need;

Retune
and
injectors
Click to expand...

Amen to that. Nelbert it looks like your maxing out your stock fuel system, seems like you have upgraded the motor to pump a lot more air, but with insufficient fuel you won't be seeing much gains.
Everything needs to work as a system and you have only 2/3 covered. Find a tuner who is experienced with hondata, and some RC engineering 370cc injectors should do you just fine. Your fuel pump doesn't need an upgrade just yet.
Even when you get a good tune (hondata is fine), this far from stock and the car will not drive as smoothly as stock at low rpms, because skunk2 also changed the pre-vtec lobes.
I have a feeling that 7000rpm vtec engagement is kind of high, there's probably a benefit to engaging the vtec cam lower, depending on what the dyno says of course.
 
Problem with lowering Vtec on a 1.6L with large VTEC lobe is that you'll loose power. And the already large primaries on the Pro 2 works all the way till 7000rpm. So your Vtec is set quite right. But anyway, once you get it tuned, you can confirm that on the dyno.

RC engineering injectors all the way
 
not sure about the idling part but bad motor mounts or axles can give you the jerkiness you mentioned. especially in first and second gear.
 
idle might need a bit of adjustment.

factory for USDM is 750+/- 50rpm. How's the throttle cable tension.... what about the throttle body butterfly... is the stop missing on the throttle body?
 
As your running stock Rascal , I dont think your problem is the same
as mine. I have found out , as the lads on the forum pointed out , that
my jerkeness stems from the mapping of my car.( although that is the least of my worrys ! ) Check plugs as sugested
earlier in the thread for signs of bad AFR.

White tips = too much air
black tips = too much fuel
rusty brown tips = perfect mix

My plugs are white meaning down low the car is getting to much air and/or
not enough fuel hence the jerkyness. hope this helps.

AS I said my problems are alot worse. I had a compression test carried out
last week and the results were not impressive . considering the engine was fully rebuilt less than 15000 miles ago. The results ranged from 150psi to 170psi. I was expecting figures in the region of 210-220. So it seems the build
was poor or the engine wasnt ran in correctly. The car is using ALOT of oil
as well so it looks like bottom end problems for me as well as a poor map!

Can any one confirm what size of pistons are available for the b16b block?
And what size are safe to use without sleaving.
The rebuild consisted of 81.25mm oversize pistons , and I am hoping when I strip the engine down I can re-bore it and fit even larger pistons.

Also what gapshould there be between the cylinder wall and piston ring ie. one thou or more? thanks Neil.
 
Just wondering mate did you buy ur ek9 from pistonheads from the north of scotland, as i recognise the mods. i was looking at buying it before if it was the same car.
 
Yes cal thats the car! its got some pretty intresting parts inside the engine
just got to get them working correctly. Bottom end either wasnt built right or broken in correctley but this can all be fixed.

can any one confirm is it possible to re bore the b16b block to accept 81.5mm pistons without resleaving. Also , if this is possible is it a reliable enugh solution to my problem ???
 
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