more dyno time

Shaun41178(2) · Post by **Shaun41178(2)** » Sat Jul 30, 2005 3:02 pm

I went back to the dyno today to try and get a bit more power out of it by fine tuning it some more.

If you guys remember at all I was sub 10:1 a/f ratio on the bottle. Its super safe obvisously but it doesnt' need to be that rich. In 4th I could really feel it bogging down.

So I went from 16 fuel jets to 14 fuel jets thinking this will be good and should raise it a bit.

Had some problems. First run the nitrous didnt' come on till like 4500 rpm. dont' know why but then it spiked and hit just a smidge over 200 whp and we shut the run down shortly after that.

Second run was clean but for some reason the graph won't display because I guess the signal got lost near the end of the run. I wish I could post it but its just blank but did show up on the screen at the shop.

The fuel curve has been leaned out a bit but is still super rich. It dropped below 10:1 and around 4500 rpm or so it popped up above 10:1 to around 10.3:1 and then dropped back below 10:1. So it seems to me its right on that edge of 10:1. Probably aroudn 9.8:1 or somehting like that. Still super pig rich. Which makes me think that with the 16 fuel jets it was like in the sub 9:1 range.

Third run was bogus and the nitrous hit and then stopped so we aborted.

So overall I am still pig ass rich. So I would need to go to like size 12 jets or increase the nitrous a smidge to get the a/fs in better tune. I do have the timing pulled about 5 degrees so I can prob give that a bump and still be safe as the plugs are still looking good. That extra 2-4 degress I can give it would help burn a bit more fuel without adding more nitrous to the mix.

Just thought I would give an update as to what I have been doing lately.

The Dark Side of Will · Sat Jul 30, 2005 5:52 pm

You could also concentrate on redoing your wiring so your nitrous actually works.

Shaun41178(2) · Post by **Shaun41178(2)** » Sat Jul 30, 2005 7:41 pm

Hey F-U sucka. My wiring = Teh good.

I think the person operating the dyno didn't put it all the way to the floor the first time we hit it. Thats my only guess. Never drove it before, had no idea what was going on. He had a hard time finding first gear.

The second time, my tps switch actually went further then the WOT switch could go and actually slipped off of the switch causing it to go open, killing the nitrous. Its hard to explain in text but if you saw it in person you would know what I mean.

I simply need to readjust my WOT switch bracket so that doesn't happen again.

I at least got a vid of the new a/f run. Its a bit grainy but you can still make it out. I can post it if anyone wants to see it.

The Dark Side of Will · Sat Jul 30, 2005 8:00 pm

Shaun41178(2) wrote:I think the person operating the dyno didn't put it all the way to the floor the first time we hit it. Thats my only guess. Never drove it before, had no idea what was going on. He had a hard time finding first gear.

The second time, my tps switch actually went further then the WOT switch could go and actually slipped off of the switch causing it to go open, killing the nitrous. Its hard to explain in text but if you saw it in person you would know what I mean.

Shouldn't these two paragraphs be enclosed in <excuse> tags?

I simply need to readjust my WOT switch bracket so that doesn't happen again.

This definitely needs to go inside <benchracing> tags! :thumbleft:

Shaun41178(2) · Post by **Shaun41178(2)** » Sat Jul 30, 2005 8:18 pm

Jesus dude you are busting my ass hard. I = Teh Own3d

I got the file to show up. So I took a screenshot of it. Just have to upload it, then I should be able to show the new numbers with the new a/f chart.

ftp is back up but I think autoindexing is turned off. Also I am "Forbidden" to access my pics. Maybe howard can change that in a bit so I can post the pic.

The Dark Side of Will · Sat Jul 30, 2005 8:29 pm

Just some good natured ribbing.
I ought to post up info about my N* build so you can return the favor.

donk_316 · Post by **donk_316** » Sat Jul 30, 2005 8:49 pm

Hey call me retarded but...cant you just size your fuel jet wayway down?

Shaun41178(2) · Post by **Shaun41178(2)** » Sat Jul 30, 2005 8:54 pm

yes, thats the goal. I went from 14 on my last runs to 12 on todays run.

its still rich. Its either smaller fuel jets or larger nitrous jets. hmmmmm :scratch:

The Dark Side of Will · Sun Jul 31, 2005 1:04 am

200 Shot

Shaun41178(2) · Post by **Shaun41178(2)** » Sun Jul 31, 2005 1:54 am

Pay for my rebuild?

Shaun41178(2) · Post by **Shaun41178(2)** » Sun Jul 31, 2005 9:52 pm

lets see if I can get this to work.

donk_316 · Post by **donk_316** » Mon Aug 01, 2005 3:16 am

Holy cock Shaun!

That is table top flat curves.....now lean it out and see what that thing can do.

stimpy · Post by **stimpy** » Mon Aug 01, 2005 11:41 am

OK, I'll admit ignorance. Is a flat dyno curve good or bad? Mine flattens out at 3500. I'm guessing that's because it's falling short of breath and can do better?

Signed

realfierotech's village idiot.

Kohburn · Post by **Kohburn** » Mon Aug 01, 2005 11:49 am

well flat torque curve is great - means a broad powerband

Aaron · Post by **Aaron** » Mon Aug 01, 2005 12:20 pm

stimpy wrote:OK, I'll admit ignorance. Is a flat dyno curve good or bad? Mine flattens out at 3500. I'm guessing that's because it's falling short of breath and can do better?

Signed

realfierotech's village idiot.

It depends. Most people like it, but that is the most people that are still under the impression that torque wins races.

I don't. I like very RPM dependent motors, where the power comes on at a certain RPM, and just climbs. Here is the dyno of my modded 3.4 DOHC:

I loved this motor, absolutely love it. 3500 rolls around, and that shit got serious. I feel that this is the key to winning races, having a powerful high end with gears to back it up. When your motor is as polar as the DOHC, EVERY component of the engine is focused on that 3500-6500 power curve, which basically means it is very efficient, and can make a lot of power. I know 218 isn't a lot, we were having some issues that day, it should have been around 240, but let's just leave at my car was having issues, and the dyno wasn't exactly accurate...

Edit: This is my 208 and 212 runs, I couldn't find my 218.

Kohburn · Post by **Kohburn** » Mon Aug 01, 2005 1:48 pm

arron if you compare the RPM range on his and yours you'll see you have a relatively flat torque curve in the same range as shaun did.. a nice 2000rpm flat spot of consitent acceleration..

a flat and predictable torque curve is great for road racing because you know how much power its going to put down - with a real peaky torque curve it becomes more difficult to control like that video shaun posted of the 400 hp turbo elise

Aaron · Post by **Aaron** » Mon Aug 01, 2005 5:49 pm

Yah my torque curve is pretty flat from 3500-5500, but it gets a big boost at 3500-4500, where both torque and HP go up at a fast rate.

The Dark Side of Will · Mon Aug 01, 2005 5:56 pm

Kohburn wrote:arron if you compare the RPM range on his and yours you'll see you have a relatively flat torque curve in the same range as shaun did.. a nice 2000rpm flat spot of consitent acceleration..

a flat and predictable torque curve is great for road racing because you know how much power its going to put down - with a real peaky torque curve it becomes more difficult to control like that video shaun posted of the 400 hp turbo elise

Shaun has the "Starship Enterprise" intake on his car, which gives the engine a HUGE high RPM boost.

The Dark Side of Will · Mon Aug 01, 2005 5:59 pm

Aaron wrote:3500 rolls around, and that shit got serious.

<chuckle> 200 ftlbs = serious </chuckle>

The Dark Side of Will · Mon Aug 01, 2005 6:00 pm

stimpy wrote:OK, I'll admit ignorance. Is a flat dyno curve good or bad? Mine flattens out at 3500. I'm guessing that's because it's falling short of breath and can do better?

Signed

realfierotech's village idiot.

Straight line racers don't really care much, as long as the engine doesn't drop out of its power band on the next upshift.

Those of us who turn corners and are sometimes below optimal downshift RPM in a slow 2nd gear cornet like broad smooth power bands.