My built NA motor sucks!

Post by **huguetguy** » Wed Mar 19, 2003 8:02 am

This is my dyno chart showing my somewhat baseline runs (before headers, after headers) and then the built engine that a crappy shop here in Richmond VA did for me...I'm so sick at the weak performance of this engine, but it's an enigma to me why it would be putting out such low numbers! and now the shop has gone out of business and I'm stuck with their crappy job...

I did do a leakdown test and Cylinder #1 is leaking 10%, the others are 2%, but I don't think that's enough to warrant this kind of power loss.

The KA24DE engine was from a 1996, the intake manifold from my 91 s13 was used with all the electronics. This is my setup:

10.5:1 JE pistonstotal seal rings (now I hear all the bad reports after the fact)0.040 overborerebuilt engine internals (polished crankshaft, new oem valve springs, etc.)lightened flywheelJWT camsJWT ecuengine set at 20 degrees BTDChotshot headers (old version)short injen intakeremoved EGR/AIV2.5" exhaust

I thought that perhaps the cams were causing the massive torque loss, but then I read that they're not supposed to lose anything low-end, so I'm not sure what else it could be...

I've been talking to some guys here in Richmond at Performance Direct, but they deal mainly with Honda, so this is not their specialty...what are some Nissan shops in the Richmond and surrounding areas?

Any suggestions people? could the 10% leakage in cylinder #1 cause this much power loss?

Dave

Post by **ADAMHU** » Wed Mar 19, 2003 8:02 am

looks good to me...what were you expecting?

Post by **I am Technoman** » Wed Mar 19, 2003 8:02 am

I have a dyno of my car making 148.9 WRHP with stock internails Nissan motor sports cams hotshot intake,hotshot header no cat and borla ehxaust. This was in a 98 degree room and with a stock ECU.

Post by **I am Technoman** » Wed Mar 19, 2003 8:02 am

What kind of ECU are you using?

Post by **huguetguy** » Wed Mar 19, 2003 8:02 am

adamhu: I expected that with higher compression, the overbore, and JWT cams, that the torque would be higher than before, not lower...when alex tested the JWT cams vs stock, they didn't lose that much, and gained quite a bit at the topend...

which leads me to beleive that something is wrong with my setup for it to only be making that amount of power...I would expect at least as much as I had before the internal mods and cams...

Dave

Post by **Open4Cycle** » Wed Mar 19, 2003 8:02 am

Hey don't let that chart hurt your feelings. That motor is probably in fine shape, just needs a bit of TLC. Another problem could be with the dyno operator. Are these corrected numbers we are seeing? If they are not, being that the test were taken on different days, you may have made a big gain and because of the weather conditions the dyno shows less torque. According to the chart though you probably need to advance your cam timing a bit. Thats why you are supposed to degree and profile your cams in during the rebuild. Then you know where you have been and where you can go. The most important thing I learned after building a dyno was that putting the engine together was only part of the process. There are to many variables that can allow 2 exactly assembled engines to not be exactly the same. TEST and TUNE!

Post by **Aries** » Wed Mar 19, 2003 8:02 am

aslo, if you are still running the stock computer, there is your problem.

Post by **TrunkMonkey** » Wed Mar 19, 2003 8:02 am

Aries, he's running a jwt ecu.

huguetguy, your numbers do look good.

is your engine broken in yet? is your jwt ecu tuned for all of your mods? what octane gas are you using?

-demetrius

Post by **91nis240** » Wed Mar 19, 2003 8:02 am

how you block off you aiv and egr valves??

Post by **1991240xs** » Wed Mar 19, 2003 8:02 am

maybe the timing is increased too much and nissans overcorrecting knock sensor is holding your engine back a little, try it at stock timing-

Website · Post by **JNM240** » Wed Mar 19, 2003 8:02 am

How badly would a stock ECU affect this? And ive heard that when JWT reprograms an ECU for higher compression, all they do is internally retard the timing. Is this true?

Post by **huguetguy** » Wed Mar 19, 2003 8:02 am

thanks for the suggestions...

demcj:the engine has been broken in, and I'm using 93 octane gas. I really have a hard time beleiving that with the extra compression and overbore, and cams, that I would make LESS power than before over most of the rpm band...the conditions that the dyno testing was done in was not that different...seems to me that the overbore and +compression would make up for any torque lost due to the cams, which from what I hear, aren't supposed to lose much lowend torque...

is it possible for the crank pulley to be installed slightly off so that the marks line up to indicate that it's set at 20degrees BTDC but it's really running at less advanced timing?

and as I stated above stock timing is 20 BTDC, which is what JWT recommends and what it's set at...

Dave

Post by **huguetguy** » Wed Mar 19, 2003 8:02 am

Open4Cycle wrote:Thats why you are supposed to degree and profile your cams in during the rebuild. Then you know where you have been and where you can go.

I've heard this before, but am not sure what that really means - how can our cams be adjusted at all - does this technique require adjustable cam gears?

Dave

Post by **Open4Cycle** » Wed Mar 19, 2003 8:02 am

Yes adjustable cam sprockets allows you to change lobe seperation (DOHC only) and lobe centerlines. I use eccentric bushings with stock sprockets. With the proper bushing you only have to drill a hole in your sprocket where your antirotation pin fits. Then I have the bushings in 1 degree increments that I can replace in a matter of a few minutes. I think this is how the nismo sprockets work but not sure. Here is a link with a very good tutoral of valve timing. http://www.compcams.com/information/Tutorials/

Post by **Oneor1** » Wed Mar 19, 2003 8:02 am

What shop did you run that dyno test at? Rosen? That dyno wasn't too too bad for the mods. I remember when we had a 240 meet at rosen a year ago alot of guys were pushing around 125-130 w/ just an intake and wires. Its all about tuning like they said. Trial and error. Take it easy

-Rick'92 Coupe awaiting CA

Post by **I am Technoman** » Wed Mar 19, 2003 8:02 am

My question is how does the car feel when you drive it? When your standing at the engine and you rev on the throttle does it sound in time? Does it bog? I can hear when a motor is in time or not.

Post by **huguetguy** » Wed Mar 19, 2003 8:02 am

what I'm comparing my chart to are these dyno runs, showing the power gain with JWT cams...so if on top of the cams, I also raised the compression and overbored the cylinders, I would think that the torque/HP should be higher, not lower across the board:

dave

Post by **Rownan** » Wed Mar 19, 2003 8:02 am

What kind of tune did you have JWT do for you? That sounds like horribly low numbers for the work done..

Timhttp://www.projectaspec.com

Post by **huguetguy** » Wed Mar 19, 2003 8:02 am

I told them everything that was going on the engine, and they said they'd take care of it, specifically:

10.5:1 compression0.040 overboreAIV/EGR removalJWT cams

Dave

Post by **Movingviolation240** » Wed Mar 19, 2003 8:02 am

not to be rude, but "in thrust I trust" not only applies to turbine engines..... boost is your freind. Live and learn.

The most HP I have ever seen from a built NA KA is 180rwhp. I honestly don't know why your numbers are so low (JWT might have a big part to play in that) I might suggest an AFC to re-trim the a/f curve. Do you have a printout of the thing on a wideband and maybe some idea of what your ignition timing is doing?

Paul

My built NA motor sucks!

My built NA motor sucks!

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