This topic contains 297 replies, has 36 voices, and was last updated by 
Surfwagon 7 years ago.
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Supposedly a hydraulic roller cam. Has adjustable rockers which the dyno guy says isn’t normal for a hydraulic roller?
Dyno guy doesn’t sound like he has much of a clue.
Love the car, are they 3 or 1-piece Simmons?
Can’t blame him when everything is LS these days.
One piece Simmons. Actually surprised at the quality and lightness of them
Putting new plugs and leads and dissy in next weekend along with new tps and map sensor.
Based on the below I think your problem is COME sent an off the shelf tune which wasn’t written for GRP A manifold.
Second throttle opens around 4 – 4500 so extra air maybe what killing it… what I would do is disconnected the little plate that opens the secondary and see if this improves the power slightly….
According to your tuner is it running rich or lean ? if it is a no group a tune it would run lean to the max after 4,500….
I had the same problem….. $1250 on a kamaker tune with knock sensor is the best $$ you could spend..
A lot of people dyno tune car on dyno ie timing etc but memcal isn’t modded.
Thanks
Daniel
So put a new coolant temp sensor in it and new O2 sensor in it, checked the cats too and no issue. Ran it up on the dyno. 301rwhp. No difference. Pulled the chip out, look what we find a COME chip. No surprises really. Read off the chip and its 10yrs old or more, has all the knock stuff turned off (yet the motor has knock sensor and its all hooked up) and the total timing is set at 24deg. This is when I start to get a little pissed off as I was told the car had a dyno tune every year to keep it at the top of its game. The chip is locked and can’t be overwritten and is clearly a stock off the shelf chip. So we start adding timing, more and more and more and the thing will not make any power. it
VRSenator065
- Adelaide SA
- VR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project)
View build HERE
Posts: 5 777
Things like plugs, dizzy cap,etc won’t make it feel down on power, it will miss etc if you know what I mean. What worries me is that you think it’s dropped in power, which infers something’s changed, which I assume the tune hasn’t. I would be doing a compression check and just make sure physically it’s all fine first. I assume it’s not running hot, blowing and smoke etc.
No good either the come chip was ripped out a writeable chip installed and tune was adjusted by dick from dicks electronics who is pretty much the father of delco tuning.
Unfortunately you like the guy from the shop are falling into the same trap of suggesting something pre-existing needs fixing. The tune hasn’t changed yet the car is massively down on power. The only solution will be something that could have possibly changed.
Things like plugs, dizzy cap,etc won’t make it feel down on power, it will miss etc if you know what I mean. What worries me is that you think it’s dropped in power, which infers something’s changed, which I assume the tune hasn’t. I would be doing a compression check and just make sure physically it’s all fine first. I assume it’s not running hot, blowing and smoke etc.
This is what worries me also. It’s not running hot or anything. Comp check on the cards though
How do you know power has dropped?
Don’t do a comp test do a drop down test as this will check top and bottom of each cylinder.
VRSenator065
- Adelaide SA
- VR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project)
View build HERE
Posts: 5 777It’s not fuel is it, has it got a twin fuel pump set up, hasn’t dropped a pump has it?
Read the plugs. Comp Test it or even better Leak down Test. See what that says. If nothing shows. Run a dial indicator on each of the retainers and turn it over. If it’s wiped a lobe u will no.
It it doesn’t just loose timing. So don’t go feeding it more or it will ping. U mentioned the diZy was loose. Hasnt turned and effected base timing?
Drain and inspect the oil and cut open the oil filter. Check for metal filings.
Single pump. I know it’s dropped power because it’s gone from frying the tyres in first and second gear to barely spinning them in first. That’s a pretty dramatic drop to me. Add to the fact the old owner was adamant it made 390rwhp and now it’s making fuckall which confirms I was correct.
390rwhp with a stock chip on 24 deg time doesn’t sound right mate.
That at sort of power it would be fair grumpy motor.
Agreed shit doesn’t add up.
I would of though the 24 degrees timing is about right
take the cover off the memcal and message me eprom number. No way making that sort of power with std come chip…..
I would look at the following.
* Leak down test
* Dizzy
* remove rocker covers and inspect
* TPS
* remove second throttle linkage.
I know this may sound like a smart ass but did you fry clutch and that’s why you cant spin tyres….
390rwhp with a stock chip on 24 deg time doesn’t sound right mate. That at sort of power it would be fair grumpy motor.
remember its 383 which makes a massive difference…
24 deg sounds OK.
Power: 358 RWHP amd 698 nm Dyno sheets to prove
http://forum.streetcommodores.com.au/showthread.php?t=8469258
13.8 @106 says otherwise.
Chassis dyno sheets mean squat. Just a tuning tool. Too many people get caught up in it.
also noted at some point his changed to a come roller cam and memcal. Bet my balls this hasn’t had a proper tune. That story he gave u about yearly would of been rubbish. Not to mention stupid even if he did.
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This reply was modified 9 years ago by
cava454.
The come chip that was in it is a standard chip that can’t be overwritten so cav is 100% right it’s never had a proper tune. If you read the whole thread on st com it says it makes 390rwhp after a change of exhaust etc. May be a stupid idea but I’m going to ring the shop that did all the work on it tomorrow and ask them about for engine specs and what power it made. See what story they give me…
Clutch is fine. If it was ever going to slip it’d do it on the dyno. The clutch is fine.
I don’t think it ever made 390rwhp and it certainly didn’t do it with this chip in it.
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