Dropped the oil last night, all looked good. Refilled with 5w-30.

Went 11.0 @ 130 with the last motor at 12lbs. I dunno about 9's, but It will be interesting to see what the MPH difference is. If I can get in a few runs and dial in WOT I'll turn the boost up.

I don't have alot of self control with the boost ****... probably should move it farther away...

 

Well the new setup is quite a bit SLOWER than the old. Little bummed about that.

Went a best of 9.99 @ 139 at 21lbs.

With my 8.6:1 compression 5.3 ZR1 cam setup on 317 heads I trapped 148 at 21lbs.

Not sure whats up. Tried 10.8-11.5AFR. No changes. Timing needed to be higher than It should. It was a total dog at anything below 13* at 20lbs.It just wouldn't rev. Ended up at 16* at 20-21lbs. Boost builds slowly same as last year and no matter what the timing or AFR the car falls flat after 6k. Doesn't break up, just noses over and stops pulling. Verified timing SYNC with the AEM, plugs look great.... Also tried with and without alky injection, seemed to make no difference. Currently dont' have the alky coming on until 16lbs or so.

I'm at a loss. Still made 9's and had fun, but I feel slightly cheated!

 

somethings definitely wrong. probably something stupid. youll find it and get back to the 8s dude.

 

Check for boost leaks.... it'll be something simple and that'll drive like a raped ape once again.

 

On my "to do" list for sure. Even with a boost leak I should be able to rev over 6k. With a boost leak I think i'd see a spike in my IAT's as well. They were actually cooler than last year 21lbs at 130* or so... 75 ambient.

Just did a cranking compression test. 160-163 across the board cold. Should be roughly 10:1 static comp. I believe the OEM spec is 175 +\- 10% warm. with my larger head gasket/cam this seems about right to me.

 

Reused beehive springs ?? Possible need to shim to within .060 of coil bind
now that you have a slightly more aggressive lobe profile yet relatively mild
lift. You could be underutilizing the spring/getting surge combined w/boost
this can act like a rev limiter. Maybe time for some duals.

 

The "old springs" didn't have many miles (1000 maybe?) on them and would easily rev to 6800+. This cam isn't exactly radical. The 1218s should easily support it. Though I may take that advice just to get another possibility out of the way. I don't know what else to check at this point. I really don't want to pull the cam. If it was ground incorrectly it wouldn't run/idle so well in the lower rpm. And even the stock cam would run better than this thing is running at 20lbs. I'll rig up some sort of boost leak check this week and go from there. I'm stumped on this one....

 

OP this is a crazy awesome build My brother used to have an LS1 RX7 that he was going to give me to start racing until he threw it into a wall at 145mph Hope to do another build like this ones day! I love this setup! How is the traction? with these cars being so damn small i know my brother couldnt ever keep it from getting lose down the track. He didnt have the rear tires like you have either though. His best pass before he crashed was low 9's. Really cool build man nicely done!!

 

Do you think loosing 18* of exhaust duration over the LS9 cam is hurting it? I would expect alot more duration for such a light car.

 

Starting to think some of these issue may be related to the excessive oil pressure i'm running. I sure didn't think the amount of shim I installed would result in such high pressure. Even with 5w30 I peg out my 80psi gauge around 4800rpm. Not sure if this is doing odd things to the HYD lifters or not. Not good either way. I didn't want to pull the damn motor out to remove the shims but I may need to. Was thinking of trying even lower weight oil, but that has me nervous as well. 0w20? Hey it works for nascar right?



I'm sure I could get away with more than most. But this cam has been a proven power maker. Peaking around 5800 and pulling strong to 6500. Thats right where I want it with the gears I'm running. I think I have other problems.

 

I'm not saying the springs are shot but rather set-up on the light side for pressures. Your new cam although not big could still have aggressive ramp rates when combined with the valve area being pressurized (2"vs1.89") may be slowing the engine acceleration. I'm saying that 150 seat and 350 open is probably the minimum needed for the boost levels you intend to use.

 

Running an ISKY "truck cam". Lobe rates are not aggressive. But you may be right. Springs are next on my list.

Managed to get the shims out of the oil pump without pulling the engine. Was able to barely get to the pump by removing the timing cover and dropping the pan slightly. Removed all the shims and put it all back together. With the timing cover off I verified cam timing again. All seems well.

Oil pressure still seems high! Pressure flutters at idle now where it use to be solid. Bounces between 45-55 warm. 70ish by 4k and it buries the 80psi gauge at WOT. Thats with the 5w-30 oil. I'll have to put another gauge on the car. Maybe I damaged the old one. Maybe the DOD oil pumps just put out more pressure?

Also installed some aftermarket beefy 7.35" push rods.

Feels stronger on the street that it did at 12lbs. Almost feels like its driving through the converter in high gear though. May have damaged the converter last year as well. Hope to get it to the track this weekend again.

 

I never though about the converter.....hard to guage it's efficiency unless you're data logging each pass. Usually the sixty time drops just a tad but the MPH goes away and particularily on the backhalf....say where it used to gain 32 and now is only 25 or so......

 

Got the new springs in... and it did nothing. The car just wont' rev over 5969... Starts feeling lazy around 5700 or so and then just hits a wall. Feels like a damn rev limiter! It's kill'n me...

 

Tired of trying to fix the RPM problem.

Threw together another funky exhaust system. 4" DP to 4" electric cutout. Cutout exits in front of passenger wheel. 2" straight pipe kick out before the cutout. Cut soud levels 40% or so I'd say with the open 2" pipe alone. Was thinking I'd add a muffler, but it's really not bad the way it is... Just need to remember to open the damn thing.

 

Think I found it!

I had removed my battery to do some other maintenance and afterwards the car wouldn't rev past 4k. Shook all the wires around by my firewall/battery area and the car died.
I found a wire pin on the supplied loom for the cam sensor that was not locked in the connector. It had started to slip out the back of the connector.

Fixed that and the engine crisply revs to 6300 or so in neutral now. I don't want to "free rev" much more than that. Rain has stopped me from road testing but I hope this fixes it. Strange it gave no signal errors, hope this is it!

 

see???

 

Can't wait to see some updates hope you get to the track soon cool build

Mike

 

Seems to have fixed the reving issue at least. Woot!

Still feels slower than the old combo. It tends to just hang at 5k once I shift to high gear.

Logs show it Rev's crisply to 6500 rpm without lagging at any specific rpm.

Shift to high gear and it drops 1450rpm. Around 5k... then it just hangs. Takes over 4 seconds to rev from 5000-5200. It's weird.



If I was "driving through" the converter wouldn't the RPM's climb nutty fast?

 

Very cool build, this has me seriously considering cutting and tubbing my all original bodied '75 Monza (factory 350/5.7 litre car too, uber rare) along with the turbo 5.3 setup going in next Winter. Although I was originally planning on just a mild T72 turbo in a rear mount config.....