I dynoed this morning with the smaller pulley (down from 3") being the only change.

I gained 16 hp and 16 lb-ft over the 3 incher (looking at SAE corrected numbers), and I think I can pick up some more hp by going to some properly gapped iridium plugs. The leveling off of hp at high rpm makes me think I may be having some ignition difficulties like what Mardi has mentioned.

Then there is always the 3" exhaust to think about, too.

400 hp, here I come.

SAE correction, 3" vs 2.87" pullies:



Uncorrected:

 

damn, you continue to impress!

 

What RPM is your VIAS switchover set too?

Looks like ~5500rpm....you need to drop that down..then again maybe not .

Very nice curve until 6300-6400rpm...what plug gap are you running?

 

Also, ever consider an eCutout?

You don't want the 3" noise all the time, so I think it would be perfect for you.

 

I've got the Harlan rpm switch set at 5200 rpm, so it might be 5500 rpm by the time the power valve is fully rotated.

My gap is kinda big at .034". I might be getting some blowout at high rpm.

By the way, according to my LM-1 data, I hit over 14 psi with the 2.87" pulley.

 

14+psi from the 2.87"...WOW.

I'm wondering if it's really spark blowout. Maybe slight detonation from the increased intake charge temps?

 

Could be, but the max air temp measured at the throttle body was only 160 F.

 

Well looks like new the BAS goes for ~$239:
http://www.seanhylandmotorsport.com/...pping_cart.php

Any chance your belt slips at that rpm?

 

Yeah, I saw that the other day. I'm really tempted.

My datalog shows a steady (although not monotonic) rise of boost pressure all the way to redline.

 

Steve,

Congratulations on your #s, I can't wait to see this in person tomorrow, You have to take me for a ride in that best.

 

I can't understand why you don't have the 3 inch exhaust yet.

Again, INCREDIBLE numbers

 

Stephen,

Another question I have is why doesn't boost build faster with the smaller pulley?

I thought switching to a smaller pulley pretty much shifted the whole curve upwards, so you'd see more whp/wtq at the same RPM as a larger pulley.

Your curves seem to be pretty much the same until after 5500rpm, is that not true? Or are the heads or exhaust or DEK manifold or something restricting the flow, so it doesn't gain until the SC really starts increasing the airflow to overcome the restriction?

Your two dynos remind me of pre/post NA Ypipe dynos looking at the difference comparison.

 

Very nice numbers!

That power level or drop, however you want to look at it, is weird. The curve doesn't get gagged or anything. What smoothing factor is that on?

 

Both are on 5.

 

very nice

id second the cutout

 

Is this an April fools gag? cuz those numbers are pretty unbelievable...props to ya...u da man stephen....keep us info on your progress....u guys never seem to amaze me.

 

Props!

Take her to the track please.

 

unbelievable !

 

congrats stephen. looks great!

can you give us a current mod list?

 

http://forums.maxima.org/showpost.ph...0&postcount=16

 

Wow! Stephen, you are my idol. All on the v1 too! Even more reason you're my idol.

3" is loud? What type of loud? Buzzy or deep loud?

 

droan at idle and partial throttle could be buzzy depending on the muffler

 

Wow very nice number.

 

Sweet. Even though something weird is definately going on up top, I don't think it's spark blowout, at least not in the same way I've experienced. When the spark is blowing out, you can feel it without question, and you can hear it. The engine will "hiccup" is the best way I can describe it. Acceleration is interrupted for just a fraction of a second, as is the normal tone of the engine, and then it will keep going as if nothing happened. Depending on the severity it can only hiccup once during the acceleration run or repeatedly, or almost continuously. Unless you exhaust and intake are both very very quiet, I would expect you could definately hear it on the dyno.

 

Instead of spending money on a 3 inch exhaust, get an electric cutout. I got 6hp from one, you will probably pick up 30 hp or more. There is your 400hp right there.

 

Agreed. Cutout > 3" exhaust.


You've got a test pipe already so it wouldn't be too difficult to hack that in half and put an electronic cutout in it, right after those nice Cattman headers.

 

wow very impressive.

 

Sweet numbers, I was contemplating 3.125 but forget that 2.87!!!I am about to go downstairs and bolt it up!!!

ATP electronic cut out, I am going to set my up with a boost controller so I dont lose out on low end torque!!!

I lost my first race NA to a SRT, I rolled down my window and told him hope to see ya in 2 weeks baby!!! its time to come back and break out the old camera for more vids. I never said I would stop boosting

 

You don't need to set up the boost controller to the cutout. I lost no low end N/A. I gained 2 ft-lbs of tq (and 6hp), and the curve was higher everywhere.

 

So you have an electric cutout on a 4th gen...how did you get it to fit? I tried to fit my cutout in the middle of my test pipe, and it's facing towards the drivers side, but there doesn't seem to be enough room for the motor because it hits the floor.
How did you get around that issue?

 

I have it in my test pipe. It faces the passenger side. It is tight, but it doesn't hit. Just make sure your exhaust doesn't move around alot because of old hangers. You have to be careful too, because it hangs lower than anything under the car. If that doesn't work, use a hammer and dent a recess area where it is hitting.

 

How much horsepower and torque do you guys think I will need to do 0-60 in under 5 sec. and 1/4 mile in under 13 sec. ?
And how the heck do I post a new thread? It isn't letting me for some reason.

 

So does that mean you have the motor facing down towards the ground? If so, doesn't that bother you? I would be too worried about knocking the motor and being out $100. I do have SFC's and a LTB under the car, but I think the motor would still hang down below them.
By denting up the floor, wouldn't you be able to see/feel that under the carpet in the cabin?

BTW- Congrats Stephen on the nice numbers. If you can get an e-cutout to fit, I think that would be a nice mod for you. Best of luck figuring out what is causing that power loss up top.

 

No, the motor is up. If you dent it enough to clear the motor, you will not see it in the cabin.

 

You don't have any pics of your setup do you?

 

ARGH!!!...Must....get...Z32 MAF...WORKING!!!!



<awesome numbers Stephen!>

 

That's odd, I've seen NA IS300's lose TQ with a 3 inch test pipe and exhaust.

Did you post a dyno? I'd love to show that to a few people

 

I can give ya one...

only thing changed between these 2 runs was exhaust:



Would have kept going up top if it wasn't for the lean condition with the A32 MAF.

 

3 inch test pipe would be why they lose torque. Mine is still the same 2.5 from the header into the test pipe, with a 2.5 cutout. 3 inch is too big for this size engine and you lose exhaust gas velocity, which hurts torque. If you can maintain exhaust gas velocity with the right size pipe for the engine size, then the less restrictive the exhaust the better. I don't have the dyno from open vs. closed cutout (only with SAFC2 tuned), but I can make one on excel.

Check my cardomain page 2 for the N/A cutout differences in hp and tq.
http://www.cardomain.com/memberpage/494867/2

 

nice numbers but IMO I think its a little too lean below 5500 rpms.