Apocolipse

LS7, mamo msd, Katech K501, milled 0.030" heads, ARH headers, tr6ix plugs, etc the works. Live at sea level and will see 101-102kpa days. Runing E10 94 @ 0.82 lambda. 92% duty cycle. Airflow calcs put it at ~600whp @ 7000 and 500tq at 5000.

Seems I am about 4 deg across the board lower timing than other tunes. I did not desensitize my knock sensors as they are there for a reason IMO.

I also road race so it builds up a lot of heat - want to make sure its safe but dont want to leave a lot of power on the table.

Even with this timing map I get blips of 0.5-1kr.

1.04g/cyl @ 4000, 1.12 @ 5000 1.0 @ 7000 so seems to be making jam...put the line in there for reference.

Thoughts? Normal?

Thank you!

jayyyw

whose heads?

Apocolipse

Ahp - not ported just milled.

Speeddemon777

rio95

MTPZ06

Plugs gapped correctly? Try one range colder yet? I'd put TR7's in for ***** and giggles and see if that makes a difference...

Apocolipse

Gapped @ 40 thou. Iridium tips.

I could try coppers vs iridium to see if that makes a difference however I have heard iridiums have a lot of wives tale stories from old school gearheads saying they will get too hot.

Apocolipse

what kind of timing are / were you running on yours if you followed along my rpm lime drawn above?

MTPZ06

Definitely correct gap. From what I've seen over the years, some guys w/ similar build & HP to your have better luck w/ TR7's, some do better w/ the TR6's. Cheap enough to try anyways...

Apocolipse

Coppers or iridium? Coppers are real cheap iridium are $10 each. Grand scheme of things both are cheap for science purposes 😁

MTPZ06

I'd stick with Iridium so you have a like for like comparison....I know I've blown more than $80 on way dumber **** in my lifetime.

Apocolipse

Preach! Lol Certainly can say the same thing here

MTPZ06

Look at post 5 & 6 here... https://www.corvetteforum.com/forums...post1592149757 Could be some optimism for you.

rio95

jayyyw

I tested TR6 and BR7s back to back. The TR6 made 4whp more peak to peak. Granted, the BR7 are a shielded plug. My 93 map had 21 degrees up top and now 26 degrees on E85.

Apocolipse

Ordered some TR7IX plugs to try out.

Thank you both for your reference on timing. More often than not I get knock typically at 4600-5000rpm (0.5-1.5 deg) with warm weather. I have gotten 0.5deg at 6600+ but it is rare. My engine is certainly more picky at peak torque. Usually logging 1.10g - 1.12g at peak tq.

jayyyw

Have you tried octane booster to rule out false knock?

Apocolipse

Yes - tried using NOS boost which contains a healthy dose of MMT. Also ran 95 octane trackside at the last HPDE day. Had knock in same spot max torque down the back straight each time but I could not "officially" conclude it false as it was 95deg and 20 min heats which builds a lot of heat up.

So with that said - there is a possibility that there is a harmonic making it more sensitive at that rpm but I do know if I raise timing up higher I get greater kr on the full load street pulls.

MickVette

I had a similar problem with the car not holding timing after some modifications.

Quote from the thread:
"I pulled the intake a few minutes ago and each port has oil in it mostly collected at each intake runner at the heads. Trying to find the source of that mess. I had the two PCV lines connected at the top of the oil tank switched. Would that cause oil to get ingested into the intake?

Update:
This was the root cause of the oil ingestion and reduced timing at WOT
"I had the two PCV lines connected at the top of the oil tank switched.""

This thread if you want to read:
https://www.corvetteforum.com/forums...o-rings-4.html

Apocolipse

Thank you for the reference. I did just recently (week or so ago) add a catch can as I found this when pulling the intake off during the cam swap. This was after my logs on the road track and tune so not sure if it was the issue...this seems to have come from the valley cover/manifold connection.