You think the colder plugs may do anything?

 

Good point Eric, I normally don't consider running colder plugs until using a power adder like N2O or forced induction. But considering you're running 200 hp at the flywheel (470 fwhp vs 275 fwhp stock) we should try at least one, maybe two steps colder plug, meaning go from the TR55 to a TR6 or a TR7. We'll experiment and see. Popular rule of thumb is run one stage colder per 75-100 hp increase.

Talk to ya later,
-Christian

 

What do you expect to run with this setup? What have you seen other people run with it? I might be interested in something like this as well

 

Christian/Lloyd

The heads were well prepped ,ie no sharp edges. Nice heads BTW Lloyd. Thanks

I'm heading to the dyno this weekend. I'm going to loosen my RR's buy 3/8 turn - I had them bound down to zero lash plus 3/4 which I know is on the verge of problems and may cause some of my apparant power problems.

I'll also take some 100 octane with me to help prove that this is real knock. I'm still running 24# injectors so I'm concerned that at tip in I'm going instantaneous lean and thus generating burst knock. I can see some evidence of this on my WB. Other than that I have run AFR's clear down to 12.0 and even into the 11's to try to quench Knock. The headers are clear of every thing. The knock counter is fine at all other times.

I'll get it figured out, just a frustrating start. Thanks for your suggestions.

Nice numbers on that 355!

 

re:

Burst Knock is a term used when the pcm sees a large MAF/MAP change and pulls timing as a preventative measure, it is not actual detonation and it can be disabled in LT1edit.

Running rich doesn't make up for improper timing, the extra fuel absorbs the heat, but you're costing yourself performance in the process. It's better to run less timing with the proper AFR than have to run rich to make up for too much timing.

Once you run race gas and if the knock sensor still acts up then you can disable it, and you can tune best timing by the datalog.

Hope this helps, let us know,
-Christian

 

I have allways adjusted rockers about 1/8 turn past zero. basically just enough to keep them quiet.

Another good thing about a dyno tune is it lets ya find problems such as KR, bad opti, bad fuel pump, etc

Some heads/cams require more/less timing than others and a mail order tune has to pick and if not guessed correctly you are leaving some HP/TQ on the table.

Regardless, even a properly "guessed" mail order tune can not compare to a dyno tune. If not properly "guessed" than there is LOTS left on the table.

NightTrain66

 

FWIW I adjust normal lifters 1/2 past zero lash and hydra-rev/similar 1/8 past zero lash.

Lloyds exactly right about mail order tuning, there are just so many variables that you need to rule out. Tuning on a dyno with a wideband is the only way to go in my opinion.

If you've got a data acquisition system with AFR, RPM, and time you should be able to dial in the car pretty well at the track (provided you get enough runs.) It usually takes me 6-10 pulls on a dyno to nail ideal timing and AFR, it will take longer at the track, so might want to do it on a private track day.

Remember to change timing or AFR not both as one affects another.

Hope this helps,
-Christian

 

Yeah, I know the feeling of not liking it, but Blackstone wont even give out head porting numbers OR cam specs. He does good work, but not everyone will give away all thier secrets, that is just how it is.

 

Any idea where the dip in torque and hp is coming from at 4200 or so rpms? I would think getting that torque back would help e.t.s alot. Is it tuning, or just the nature of the heads and cam?

 

I'm not working with a mail order tune here. It's all me on the street with Datamaster, LT1 Edit and my Wideband at this point. I kicked my fuel pressure up to 50 and rescaled my injector flow rate up to compensate. That took care of the 95% duty cycle at 6300. Loosened up rockers to the point that they make a little noise at cold startup but quiet down after the block & heads warm up. Sunoco 94 helped knock a little bit so I just picked up 6 gallons of Sunoco CAM-2 GT100. Dyno on Friday. I sure would like to see 380 or 390. 400 and I'd have a major woody.

I'll post results if they're worth a crap.

Steve

 

Those are impressive numbers and the power curve looks great

 

SLP233,

Well, the guys literally spending 30x the $ on this stuff aren't even given flow numbers . Really, in the racing world, from what I've always seen, and done... there's no sense in telling someone something you don't have to. If I told you the .050" specs.. what do you know? Just enough to get yourself into trouble . If people are hellbent on knowing what they run, that's fine, it's not like it wont make power, we can get anything from anyone & suggest readily available grinds all the time. Until I sell a thousand cams like summit, it isn't exactly making me $, so I really don't care who's stuff people want to run .


Eric,

Yeah the colder plugs will likely do something.


Brain,

Its an EFI thing IMO. To lose cylinder pressure at that point, to me, points to a timing issue - most likely knock retard. Whatever is causing that noise that the damnable PCM thinks is detonation, I don't know. FWIW, people got along fine before without the damnable things, like idiot lights, and I'm disabling mine.

 

One last thing, I saw your modlist, but didn't see gears mentioned. Are you still running stock 3.42s? If so, do you get any cam surge? If so, how high do you have to turn it before it goes away? If not, what gear are you running, and how livable is it?

 

Just returned from the dyno. Peak HP was 375 SAE and Torque was 336. This was about a 40HP increase with Lloyd's heads. All other mods were identical. Compression was taken up to about 10.8:1. Stock bottom end, thru B&B triflows, 12 bolt rear, and ET streets. Motor was still pulling at 6400 so another 200 RPM may have netted some better numbers but I'm a wuss. These numbers were in the range I was expecting. Now, lets see what it'll put on a time slip!

Steve

Oops, looks like I gotta change mi sig now.

 

what compression ratio do you have?