420 rebuild thread

[1slow95]

Hey, it actually runs! I definitely need to work on the tune, it seems to be pretty rich right now. I still need to install my new wideband, I can finish that tomorrow.

YouTube - 420ci stroker first startup

 

[Killercanary]

That's awesome!!! I need to re-read on how to do the EPM/LS1 coil setup. I still get timing errors and once I put a power adder on the car I know I can't afford to have them.

 

[ProKiller]

OT: Does that mean you've made up your mind Paul and put the turbo on?!

 

[1slow95]

I tried to take it out for a drive today, but I made it 3 miles and it died at a stoplight. It barely started and I made it to a parking lot where it died again and wouldn't restart. Had to get a jump to get it going. I made a bunch of changes to the idle and startup settings in the AEM and I think it's fixed now. Gonna go try it again in a few minutes.

Another video. I think it almost sounds better than it did before.
YouTube - 420ci stroker idle and rev

 

[xr8d302]

Awesome to see you're still going hard man! Looks great!

Off topic, but where in Ohio are you? The only reason I ask is because...well....I'm here....with my mustang....

I completely forgot about everything until I saw the license plates here, then I said...."holy sh$t Mike is somewhere around here"

 

[nmcgrawj]

Where are you in ohio man? West side of the state maybe?

 

[xr8d302]

Right now I'm in Geneva, which is just east of cleveland. In a few hours, I'm back on the I-80 West all the way to Montana. You're nearer to I-94 right?

 

[1slow95]

I'm on the Ohio/WV border close to I-77, but I'm in Myrtle beach this week.

 

[xr8d302]

Damn you! Ah well, I'll come back.

 

[1slow95]

Didn't feel like starting a new thread....Got just over 800 miles on it, still running good. I have the tune just about figured out I think. I know it's still got a little power left in it, just not sure how much. I ran at the track a few days ago and my best run was a 12.28 @ 115 mph. That's down .4 and 5mph from my previous best run. So I'm guessing I lost about 40rwhp from the old setup. I figure I might pick up 5 or 10hp with a better tune, and maybe a few hp once it's fully broken in.

A friend of mine has a S-trim for sale. I'm thinking a couple pounds of boost for 500+rwhp should hold me over next summer while I save for a big ass turbo and fuel system.

 

[BlackVert]

what kinda compression does that monster have? boosting that beast =

did you also redo the exhaust and make it more daily drivable, so you would choose to drive it more now?

 

[1slow95]

Should be 9.5:1 now, shooting for 600-700rwhp on 8-10# eventually.

Exhaust is the same, I just lowered the compression to help driveability(and add boost). Right now it's the best it's been since I pulled out the stock engine. Only problem I have is some bucking still in the 1200-1500 rpm range, mostly on decel with no throttle.

 

[1slow95]

Ran a new best yesterday, 12.17 @ 116.5mph with a 1.92 60'. What's odd is my 1/8 was 7.91 @ 94mph, which is down only 1mph from old setup and about .10. So why would I lose 1mph in the 1/8 and 4mph in the 1/4?

I got some good videos with my cousin's camera, just waiting on him to send them to me.

 

[nmcgrawj]

So why would I lose 1mph in the 1/8 and 4mph in the 1/4?

This goes into the question i posed to Kurt in another thread about what makes a car a strong "high end" or a strong "low end" car.


I'll stay tuned...cause i think i got the explanation but im drawing a blank at the moment.

 

[1slow95]

A couple things I'm thinking of that could cause it... One is maybe my tune is still a little weak in the mid range and that's why it's not pulling as hard in 4th. I'm at 4600 rpm at the start of 4th and around 5850 at the line.

Another problem is my throttle accel pump/tip in. I have a lean spike between gears and there looks like a moment of hesitation before the car takes off. It seems to be the worst on the 3-4 shift. Once I get that fixed it may pick up a tenth, and maybe a mph or two?

Possibly the most likely situation is that I shift out of 3rd right at the 1/8 mile mark. With my old setup perhaps I was shifting before the line and the extra shift time is why my 1/8 was "only" 95. Now that my car's a little slower, maybe I'm shifting right at or just after the line and that's why I'm still seeing 94 mph.

 

[Venom351R]

Get some slicks on that thing and rip an 11 second pass

 

[1slow95]

When I first started the engine I had somebody else check the timing while I set it in the AEM. I knew I should have checked it myself, but it ran ok so I assumed it was right. I just checked it tonight and it was at 14* instead of 10*. That explains why the car seemed faster when I took out timing! I had it set for 34* at WOT in the AEM so it was actually seeing 38*. I'm thinking 34-36* is probably where it'll make the best power... I know the old setup liked 34*.