[Gmecm] 305/350 Swap 10-month Progress Report...

[nhromyak at comcast.net]

Interesting findings.  Thanks for the update.  

I especially like how you went back to the stock coil and found your BLMs returning to a range the computer can compensate.

The idea of the ignition being TOO powerful falls in line with Dr. Jacobs (of Jacob's Ignition) findings and book I have.  Basically, too much spark literally displaces the fuel and misfires.  Hence, the need for more fuel.  But depending on head design, the flame can either be more powerful, or in most cases - less.

Glad to hear you got it smogged.  Too bad you couldn't do it without the catalytic converter.  

I have been tuning mine for over a year now, still not there....but close!

-------------- Original message -------------- 

> I thought I'd drop my favourite lists a quick report on well overdue progress on 
> my TPI 350 of significance. The last time I spoke up it was with the results of 
> my failed 15mph treadmill smog test and how my NOx levels were too high. 
> Suggestions were made regarding timing reduction to pull the NOx down. Well I 
> reduced my initial from 6BTC to zero and the only thing that came down was my 
> gas mileage. I put the 6 back in and finally broke down and installed a new cat. 
> Car passed 15mph with NOx 10% below max allowable. Strange though that the 25mph 
> test remained virtally unchanged from when I had it tested with the gutted cat. 
> The good thing about all this testing was that the tests confirmed the idle/low 
> speed 160 BLM's I was getting. 
> 
> Moving on I remembered from tuning my motorcyle years ago how I though I would 
> pick up some power by installing some high zoot coils. Installing a set of Accel 
> coils suddenly made my bike run incredibly lean. I was on my third or fourth set 
> of *significantly* oversize jets when I thought to myself how counterproductive 
> for a street driven bike what I was doing was. I was probably gonna get more 
> power but at a significant loss in mpg. I removed the Accels and went back to 
> stock and the performance I was used to returned. When I pitched the well worn 
> coil-in-cap dizzy on my motor and installed a newer remote coil unit I installed 
> an Accel coil instead of OEM. A week ago I swapped the Accel coil for a correct 
> GM coil. BLMS dropped slightly in all ranges. Now I the only place I got 160 was 
> at idle. 
> 
> This past weekend I finally received from my cleaning servuce and re-installed 
> my #24 LT1 injectors that when I installed the motor I plugged with vaseline via 
> my stupidity. Remember that mistake? I have always heard bad vibes and stories 
> about the #24 Accels that I put in couple of months ago and now I think there is 
> something to those stories. With the LT1 injectors back in my idle BLM dropped 
> to 140. BLMs in all other ranges dropped 10 to 20. In some places I was seeing 
> 119. Previous VE changes have made it obviously too fat in some places. Idle is 
> smooth and general response at all rpm changes has improved greatly. 
> 
> I feel like I can finally do some serious tuning. 10 monts later!!!... Now those 
> SLP headers are calling me. "Put us one. Put us on"... 
> 
> Mike 
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