Hey all:

I finally got the new engine tuned today. It is a nothing special combo, but I am real happy with the results.

First engine, was a stock rotating assy. 346 with a set of home ported 98 ls1 heads,ls6 intake, ported throttle body, stock Maf, under drive pulley,and a tr224/114 cam,10.1 compression with a home built header/exhaust system to fit it into the miata. The numbers were 384/382rwhp/tq.

Everything as above, but Stg 1 Livernios Ls6 heads, a 383 stroker assy., and running a compression of 11.1. The new numbers 423/434/rwhp/tq. I am happy with the power curve. Its not the Hp that is the key. The torque curve works with my gearing. 40 more rwhp and 50 more rwtq everywhere. Same looking power curve....just more of it. I will post the dyno sheet tonight when I get home.

My highway cruise mileage was 25.6, 25.9, 23.6, 21.6 mpg. The speeds and traffic where the cause of the lower mpg's. I have been getting around 17-20 mpg city/highway/and some fun accelerations.

Top speed as current has been 160 mph. It still has more in it. And now the new found power will help. Road course fun, here I come!!!!!

 

if your still running a tr224,then you would pick up a LOT of power with a bigger cam.That 383 will absorb that tr224 like nothing.

 

good numbers though for a miata by the way...What does it weigh in at and what gears,tranny are you running??.

 

want to see a video pleeeeeeeeeease

 

Awesome. Can't imagine that power in a miata.

 

dude that has got to be a blast to run. You dont need any more power then that in a miata

 

having camera problems. Yes it absorbed the cam.......but the power under the curve is much better then it sounds. It is 2650lbs. T-56 trans. 3.27.1 pos1 rear.

 

http://www.ls1miata.net/gallery/Dyno-Day

Dyno pic. and dyno pull.

 

It runs 600cc sport bikes with this little cam. A Zx-636 went down on Saturday, I had him by a car length.

 

423/434 in a 2600lb. car has got to be insanely fun. I bet it sounds about like a stock LS1, too. My friend has a 383 with an F13 and his sounds about like a 220 in the 346.

 

On The Tree


O.k. Guys, I know I could of made more power with another cam. I stayed with this one, because I like the feel of it for everyday use as a daily driver, it has good power for road racing (Not so hard on valve springs), I needed the torque to get this thing moving, and I didn't have the money for a new cam at the time. I had some medical expenses etc. I figured I would see what see would do. A cam swap is in the future. But, I want to get some miles on the car, and get it dailed in for some road course use. Again, I also had a few reasons not to put a cam in it....or concerns .

1. I made my own 4-2-1 headers. They work for my appilication, becuase everything is tight. If I had the f-boby or vette headers, I know my numbers would be better. So my exhaust is my limiting factor, more like a mid length header, so I am not getting the full story.

2. I need a larger air filter and some fresh air. Another reason the numbers are alittle low. It is tight under the miata hood. I will be finding ways to help me out there to. The filter being off alone helped pick up 5hp+ and 5 lbfttq+.

3. Even though the car is light at 2650lbs. I am trying to get his thing to pull as soon as I can, due to the gear spacing. I am running a T-56 trans with a 3.27:1 rear end and 24.5" tall tires. 1st gear 0-57mph, 2nd gear 57-85mph, 3rd gear 85-110mph, 4th gear 110-140mph, and 5th gear 140-189mph...if she can pull it. The gearing is wide, so If I had a mid to top end cam it would hurt me more then help me, because it keeps me out of power band, when below the peak torque curve. City driving, road course, or autocross.

When I get out of 1st at 6k....it puts me at 4250rpm at my peak torque zone, of 430 plus torque and pulls to 6k, shift again and then I am at 4400rpm....430plus torque again, at my peak torque. This is good for drag racing, put all of the power between though to marks. Great......for drag racing, but not for road racing. I wanted it to pull the car without any issues coming off the corners when below my peak torque curve. I have 355rwtq from 2000rpm to 6200 rpm. The old 346 setup doesn't make that torque until 3500rpm. 1500rpm difference.

4. My point is yes, you all are right about a different cam putting down better upper end numbers. I agree, but my intended use was different then most. I went for the mid range, due to gearing and the style of driving I wanted to do. And my conversion also is not as friendly to full length header and induction mods. Compromises of my conversion and my skill to make it all work.

Again, I am not unhappy with my numbers. In fact, I am pleased. The car drives almost stockish, very user friendly. No cam surge. Good mileage. A sleeper, do to very little over lap coming from the exhaust. I am running 4 mufflers to keep it from being to loud. And it pulls harder then the numbers look. TORQUE!!!! And my mileage is great for what it is......a home built hybrid do it yourselfer conversion.

Thanks Guys

I will try to post a good video with the car flying.
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