What should the total timing be on a tpi engine? I have always wondered as everything I have read on the subject says best power is made with no more than 36 or 37 degrees total timing. And in my best judgement it shouldn't matter whether it's fuel injected or carbed. The last time I checked mine I had close to 45 degrees. My engine seems to run fine, but i feel that is way too much timing. Am I wrong in my thinking? My engine is a 383 with about 10.25 static compression, AFR 190's, zz9 cam, accel superram setup and a mail order custom chip. Do I need to get a laptop hooked up to this and get the timing under control or am i over reacting?

 

It is difficult to see the WOT SA with a timing light. There isn't a load on the engine for a long enough period of time when at a standstill.

The attached picture is the SA for a '88 L98 Firebird. As the LV8 increases (more load) the SA drops off. The lower LV8 areas are for decel and cruising.

RBob.

 

Never have seen a SA table. After looking at it, it makes perfect sense. So the only real way to know what my timing is, is to do some data logging while under full load. Or better yet, put it on a chassis dyno. The latter being the safest, since it's in a controlled environment. Thanks.

 

If you think it is knock retarding you can build a simple light to indicate this. Check out the ebl p4 on dynamicefi's site I know if require you to rewire from maf to sd but it would be a awesome upgrade.

 

The engine runs really good, so I never thought it had any spark knock. I was just curious as to why I was seeing 40+ degrees of timing. Hopefully next year I can get it on a chassis dyno to see how close the tune is since the chip was burnt based on engine and car specs.

 

Yes, best bet is to data log. Although on a '7165 ECM getting the ALDL to connect isn't always easy. It is a dual baud set up (160 & 8192) that takes some finesse to connect and stay connected.

So work on that well before wanting to take the car to a dyno.

RBob.

 

Possible the initial spark timing in tune does not match the physical?

ie. My IST is 9.8 in tune and same at dist with the plug detached.

 

I don't have a laptop as of yet, but would like to get one maybe as a Christmas present to myself. IYHO which cable should I get, from whom, and what should I do to get it connected? Also what is a good user friendly program for data logging?

 

Cable can be had at CraigMoates.

Most use TunerPro RT. Note it is updated occasionally. Free I recall. to avoid the popup I think it is $20. See the site.

winALDL is free as well but has less features. I dont think it has been updated. I used about 8 years ago when I started. Pretty simple straight forward.

May wanna take a look at TunerCat just for the look.

 

http://www.moates.net/aldu1-and-cabl....html?cPath=64

and if you haven't gone to $6e yet you should !!

 

I did a little reading the other night and didn't find an answer I was looking for. So I will ask now. Why should I goto the $6e mask?

 

The $6e mask will give you a better cold start, it increases pw during cold start and you can eliminate your problematic 9th injector.

 

I must be running the $6e since I had the csi deleted. I don't drive it when it's cold anyways but still went and had it deleted.