NonTurbo LT-8 update
 

Hey all,

Just wanted to provide another update for my car. Brandon and Ray returned once again to perform some final tuning on my car and I must say that I am more happy with the car.

I netted 160 rwhp and 128 ftlbs of torque. That is rougly where I was before, but the curves looked much flatter than they were before.

Also, I am sure I am loosing HP since the previous dyno numbers were based on stock 205-60-15 tires and this time I had the heavier 17x7 wheels. So, I figure those wheels are robbing me of about 5% (figured based on some Honda before and after dyno runs with swapping wheels).

Apparetly the VDI wasn't actuating all the time and there are some dyno runs of it working, not working, and wired open. 139hp and 128ftlbs or torque closed, 160hp 122ftlbs wired open.

Anyway, the reality test tonight was me vs a last generation N/A 300ZX. He had me off the light, but my top end power reeled him and and it was all me after 2nd gear.

According to Brandon and Ray, the car is still a little rich so I think there is a few more HP to be had, but eh, I am happy.

Thanks again Brandon and Ray!!

Oh, one other thing. The car is no where as stinky as it was before or ever has been, cat or no cat. There is no cat currently, so I think I should be able to pass emissions this year when the cat goes back on. With the OEM computer I barely passed and sure wouldn't have passed this year.

Carl

Thats crazy thats on stock ports....def. makes a diff. when a rotary actually has afr's and timing it likes. When you get eager down the road, give it a nice street port and see what you put down.

-marc

This is encouraging!!! I pulled 117HP on the stock ECU and wired open ports yesterday :( . Can I get a copy of your map?

Nice!&nbsp I didn't realize how rich those NA's ran on the stock ECU.&bnsp I was trying to help another NA owner tune his stock ECU car with just an A'PEXi S-AFC, and we were jacking the pulsewidths down 10%+ almost across the entire RPM band...


-Ted

Yup, that sounds about right. The N/As are extremely rich. The sad part is, the 86-88 non turbos are leaner up top than the 89-91 non turbos. So I can only imagine what fuel corrections can do for the later cars. You might even see benefits from leaning it out more than what you already have.

Another update - I got Carl's dyno charts scanned. I'm pretty pleased with the way the car turned out. The car has reached the limit of the tiny (sorry Carl! ;)) HKS exhaust it's got, and there's probably another 1.5hp or so in tuning injector timing for better atomization, but I think once Carl gets his VDI actuation issues worked out the car will be perfect. Lots (for an N/A rotary) of low-end, and it pulls really nicely all the way up! :)

Brandon
BR7 Racing

can you take a screenshot of your load map? and then ill make one like 5 points taller just to be safe. :D

Well, the car's in 3D mode (as all good cars should be ;)), so it's not quite that easy. I will get you the dyno chart, though! :D

Brandon
BR7 Racing

How about an upload of the MAP?

Just to chuck in a few cents...

Mike Gallagher's old '86 base (I built the motor for it) had just a VERY strong motor, cone intake, Mindtrain header/midpipe, and Dymoax cat-back. That's it. Made 160hp to the ground. Stock ECU, no Super-AFC or any other tricks.

I would think/hope the Microtech can pull some more horsepower out of the bag. But, it comes down to one thing - tuning NA's is a real chore. They're just damn tricky to get power out of.

Anyhow, I fully agree that that HKS 50mm exhaust is choking the car down. I think it's just too conservative. My old roommate Jay noticed a considerable butt-dyno improvement going from the HKS 50mm to an N1, especially up top.

Yeah, I have seen stock NA's respond really well to some leaning out with a Super-AFC - they really can use it. I think it's due to the stock maps being designed to keep the cat alive :).

Dale

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Due to a liver illness and feeling extremely weak, I am going to try to keep this sweet and simple, one important note for people to keep in mind about my car is that the motor has approx 75-80,000 on the clock, 7.9, 7.8, 7.9 compression on the front rotor and 7.2 on the rear three faces. My motor is no where near the built, fresh motor that I would like it to be. Honestly, when you compare what my engine has done and how it has done it, with dyno curves, I think it is pretty impressive.

I'm not trying to dog your accomplishment - I'm just saying I have a feeling there's more power to be made with your setup.

BTW, your engine isn't THAT bad on compression - that's pretty darn good.

Big point I wanted to make as well is tuning an NA is tricky - people with the same setups vary wildly on power output.

I'd be interested to see the power difference with a bigger/less restrictive exhaust. I bet you can hit 170 with a better cat-back!

Dale

Yep. Ray and I tried a few different tricks to get more power out of it, but nothing extensive. Like I said, I think there might be a smidge more in injector timing, but not much. I briefly considered dropping the catback just for one pull, but we really didn't have time. It sure would have been fun, tho! (open header woo!)

Also, keep in mind that this is an S4 block w/ the heavy, low-compression pistons. I think we could have picked up another 5 lb-ft in the midrange with some 9.7:1 rotors. No worries, though. Carl's got something much better in the works. :D

Brandon
BR7 Racing