KL-01 VS KL-31 cams

[Nallboy]

As the subject says, I'm wanting to compare the two types of cams that come on ZE, curved=KL-01=low-end torque, straight=KL-31=higher torque band. --Yes, I did do some searching first-- Has anyone noticed a real difference in quarter times? I've heard that the KL-31 are "more aggressive" Right now I like that the curved will fit right in, but I also kinda plan on getting the new mani that CZT is coming out with. In addition, I would like a small turbo sometime (a year or two) in the future, and I would assume that torque on the low end would be a good thing for such a setup. What are your thoughts?

[TsiMiata]

My ZE has KL-01 cams. I actually think the low end is pretty weak. The car really doesn't come alive until after 4,000rpm. Could also be something else going on with the car I haven't discovered yet.

[lazzyie]

kl31 ecu is for the straight necked motor so you get a basic VTec type kick after 4000rpms, run a kl ecu and your power will be lower in the band

[TsiMiata]

I didn't realize there was a difference between the straight neck and curved neck ECU's. Just that there were auto and manual ECU's. How could you tell a curved neck ECU from a straight?

I do get a kick at ~4200rpm's. Is fuel, VRIS or a combo of both causing this? I have a feeling that the car is running a bit leaner than it should also. The reason I say this is when I first installed the engine I kinked a rubbber fuel line. Drove it like that for a day. Car was VERY slow and the exhaust sounded extremely tinny. I unkinked the line and the car was way faster and the tinny sound much improved. The exhaust still sounds a little tinny and when the engine is heat soaked that honda rice boy sound gets a little worse. When I went to the track the other day I left the hood closed between one of my runs and my times dropped almost a 1/2 second and the exhaust note was very tinny. All this tinny(could I say tinny anymore?) sound makes me think I need a little more fuel.

One other thing to note is using the 1/4 mile calculators online I have 160whp. Seems a little low. Then again a dyno number, which I would hope for 170-175hp, wouldn't take into consideration areodynamic drag where as a 1/4 mile time will.

<small>[ May 03, 2004, 01:24 PM: Message edited by: TsiMiata ]</small>

[Nallboy]

yeah, I'd never heard anything about the ECUs being different either...

[papa roached]

the only differences i can think of is VIRS points

[Taras]

As far as I know, as this may not relate to cams as much as to the intakes differences or both. The difference between a curved neck and straight is that torque is 700 rpm lower than on a straight neck, but I think the rating is the same, it just comes sooner. As far as KL31 and KL36 ECU's are concerned, they seem to be the same.

[babyblueMX3]

i have the kl31 cams, kl36 ecu and millenia manifold..and when i hit 3600rpms exactly i can can fell an increase in torque...I mean the difference is really noticeable...this is the vris opening right?

[TsiMiata]

Sounds like the KL36 ecu may switch the VRIS at 3600rpm. My KL31 kicks at 4200.

[TsiMiata]

I did some research and it seems that we should be using the KL62 ecu for a curved neck ZE engine. But its not that easy at least for pre 95 cars, which is all the american spec ones. The KL62 ecu has four connectors and uses a MAF. The american MX-3 uses three connectors and a VAF. It also must see the auto transmission or it throws up all sorts of error codes. Wether or not these codes effect performance I don't know. On later cars the ecu would plug in and with just some small wiring changes for the air meter it will work. But there is the issue of the auto tranny error codes.

I do see every once in a while people asking what is needed to run the ZE in OBD2 cars. This would seem to solve that problem. For the majority of us it doesn't help at all.

The only solution I can see around this is to run the KL31 or KL36 ecu and a SAFC to adjust the fuel and then some way to adjust the VRIS manually. The VR tuner which would be agreat option is no longer made, why I don't know. There is the MSD rpm switches. I really hate those MSD rpm controls though. They are way bigger than they need to be and they rape you on price for the stupid pills. Overall they are just very clunky to use.

There are some people running the straight neck ZE engine in their MX-3's. With the KL31 cams and the straight neck manifold those should run great with the KL31 & KL36 ecu's. Before it didn't really seem like the extra trouble was worth it for the straight neck manifold but maybe it is.

<small>[ May 04, 2004, 11:07 AM: Message edited by: TsiMiata ]</small>

[IanL]

Originally posted by TsiMiata:
I did some research and it seems that we should be using the KL62 ecu for a curved neck ZE engine. But its not that easy at least for pre 95 cars, which is all the american spec ones. The KL62 ecu has four connectors and uses a MAF. The american MX-3 uses three connectors and a VAF. It also must see the auto transmission or it throws up all sorts of error codes. Wether or not these codes effect performance I don't know. On later cars the ecu would plug in and with just some small wiring changes for the air meter it will work. But there is the issue of the auto tranny error codes.

I do see every once in a while people asking what is needed to run the ZE in OBD2 cars. This would seem to solve that problem....

I'd like to think it would, but I don't see how. Assume the KL62 ECU is the one used by the JDM Millenia, if it's for a ZE and it matches the curved neck. Now everyone says that the JDM still does not use OBD2, so I don't follow how it would work in an OBD2 car.

On the other hand, if it's for a '95-on N. American Millenia, it would be OBD2, but it wouldn't be for a KLZE. Or am I missing something?

[TsiMiata]

The OBD-2 wiring uses the same 4 connector setup as the KL62 ecu. I found a thread on probetalk where someone converted their 96 probe to run the KL62. They listed the same issues that I did above, just the maf wiring change and the error codes because there was no atx.

[Nallboy]

So, the cams don't really have a big difference between them? Sounds like it's just the different ECUs that create the variation in VRIS...

[IanL]

Originally posted by TsiMiata:
The OBD-2 wiring uses the same 4 connector setup as the KL62 ecu. I found a thread on probetalk where someone converted their 96 probe to run the KL62. They listed the same issues that I did above, just the maf wiring change and the error codes because there was no atx.

OK, its an OBD2 ECU, but what is there to say its for a KLZE?

[TsiMiata]

Its not an OBD-2 ecu but happens to use almost the same exact wiring and pin outs. It is the ECU from a J-spec millenia.