Threw the old turd of a car on the rollers for the first time in 10 years. I don't think the 10 year old spark map from when it was a stock 98 LS1 with LS6 intake, headers, and a lid is cutting it any more. And apparently I live under a rock and am running the original 22 year old coils. Torque numbers seems healthy, but the HP seems low especially given the torque figure. And that torque peak seems low in rpm. I did clean up the fueling a bit but it definitely needs more work. Lambda was 0.86-0.88 during the pull. Motor has 165k and is being spun to 6800 so a compression and leakdown test is on the agenda either way. Thoughts other than it needs more tuning?



Slightly lower pull, but better resolution:


Specs:
Stock 98 LS1 longblock
crank scraper
high pressure pump
fresh OEM truck valve springs (forget the PN, whatever is the factory stock replacement LS1 part now)
chromo pushrods
trunion upgrade
102 lid, MAF, and throttle
Mamo ported 102
ARH 1 3-4 catted headers into 3.5" single dumped under the car
Quartermaster 7.25" twin disk
10% underdrive
updated to late LS6 PCV with single catch can
heavy 18x12 F14s w/335s

 

Do the leakdown/compression test before deciding anything, though 165k isn't that high IF it was maintained properly. I'm sure a fresh tune won't hurt things though....

 

It's been maintained as well as could be, but autocross at 1.5 lat G for 3 seasons before the oiling upgrades may have been the beginning of the end. And I can't imagine the stock valve guides are happy. It's only had the intake and oiling upgrades, M29, and 6800 rpm limiter since 2019, so maybe 100 track miles.

I suppose there is only one way to tell. Need to wire up this air compressor I guess. Thanks!

 

Weeeelll.... since you put it that way, she might be gettin' a bit tuckered! LOL
Sounds like it's been a fun trip. You might just consider going thru her for a good freshening!

 

If this bottom end comes apart it's to build a 5.1. I'm not convinced that I'm in a spot to drop that kind of coin on a toy, so for now I'm trying to limp this thing along through the 2021 season if it will let me. But if I suppose if I have to a stockish rebuild wouldn't be horrible.

 

leave it alone. making the power it should, especially on 98 heads.

 

A leakdown/compression test won't hurt anything, and will provide good info.

 

Finally got around to doing a hot compression check. 1-8 in order: 146, 165, 158, 156, 152, 147, 152, 142

 

leave it alone.

 

I think I'm going to keep an eye out for a cheap LS2. Missed out on one due to being in the process of a house refinance. But if the right motor doesn't come along I think leaving it alone is the correct answer for this off-season. It does need more power, but I'm not sure building a 3.9" bore is something I'm interested in. Nor is spending a ton to build from scratch.

 

With that power curve, would there be a point in spinning it past 6000rpm on the shifts? Just curious....

 

No, which is why it gets spun to 6800. The only thing this car needs to do is go from 27-73mph as quickly as possible without blowing the tires off it.

 

valve springs.