304 Why so sluggish?

[v8commy]

The jolting is normal for a lumpier cam at low rpm. When you hear it at idle and it lumps over, picture connecting the clutch up with that, the wheels will jolt when the revs go up then down, even though its a little bit, that wot makes it jolt at low rpm if that makes sence. My cam is 230/230 and i alway keep it above 1800 when cruising, otherwise your going to start damaging you drivetrain. Thats why people start talking bout driveability when going bigger cams. I changed my manifold from a starr (which is a glorified banana manifold) to a torque power dual plane highrise and my driveability when up alot. When company suggest diff ratio changes with a cam change, it is to get the car out of the "sluggish" range quicker and it get it into its power making range. So I dont think there is anything drastically wrong with yours, you just need to make a few upgrades with the cam..

yeh thats why you shouldnt lighten your flywheel as that's carrie's the engine over its dead strokes

 

[delcowizzid]

how much extra timing over stock are you running in the lower rev range 30 40 and 50kpa areas mate.

 

[stocky]

how much extra timing over stock are you running in the lower rev range 30 40 and 50kpa areas mate.

here it is
30 40 50
40.08 40.08 38.67
40.08 40.08 38.67
40.08 40.08 37.97
40.08 40.08 37.97
40.08 40.08 40.08
40.08 40.08 40.08
40.08 40.08 40.08
40.08 40.08 40.08
28.13 40.08 38.67
28.13 35.16 35.16
28.13 28.13 28.13
23.91 23.91 23.91


i dont think its any different to standard. the only real difference in the spark is around the 80 90 100 area.


i also took a photo of some spark plugs. theyre kinda half black, half white. not sure if theyre bad or not

 

[96SEN8R]

yeah thats what i was thinking too. the jolting caused by the lumpyness of the cam. ill try to avoid lower revs while crusing then.

i think im going to have a look at leads/plugs, since one of the plugs failed a couple of months ago so the others might not be that great anymore. the tune is a 284 based tune, with a few changes to suit the cam, so that shouldnt be the problem, although i might try fiddling with the timing a bit.

how did the drivability improve when doing the manifold swap? did you lose much bottom end power or economy with the TP manifold?

fuel econ was better, and the engine didnt seem as grump at low rpm. if ya want to compare, u can take mine for a quick spin and see wat u think. that might be better then forkin out 2.5 for a new manifold and not liking it. but having said that, ur manifold wont make much power ova 4ish grand where the tp does to 6.8. these manifolds make sweet torque down low. well it did with mine and other blokes ive spoken to..

Sorry just saw ya in melb, i thought u were in adelaide for some reason

 

[delcowizzid]

what tune are you useing as a base BMZL looks like stockish timing in the area you are having issues with and more up top higher in the revs. ide be giving it more timing in the cruise area down low rpm where its stock it will help it cruise better and make up for the loss in power from not inhaling as much air down low.you get that aldl cable yet when you get that you will be laughing youll actually see where its cruising in the maps

 

[stocky]

fuel econ was better, and the engine didnt seem as grump at low rpm. if ya want to compare, u can take mine for a quick spin and see wat u think. that might be better then forkin out 2.5 for a new manifold and not liking it. but having said that, ur manifold wont make much power ova 4ish grand where the tp does to 6.8. these manifolds make sweet torque down low. well it did with mine and other blokes ive spoken to..

Sorry just saw ya in melb, i thought u were in adelaide for some reason

haha damn oh well. yours has a throttle body yeah? what do they cost, as the manifolds are around 900 i think. then i also need the filter for on top. any other costs i need to look at?

what tune are you useing as a base BMZL looks like stockish timing in the area you are having issues with and more up top higher in the revs. ide be giving it more timing in the cruise area down low rpm where its stock it will help it cruise better and make up for the loss in power from not inhaling as much air down low.you get that aldl cable yet when you get that you will be laughing youll actually see where its cruising in the maps

yeah i might try raise the timing a little there. nah no aldl yet. hoping it comes soon and then i can work out whats going on

 

[delcowizzid]

even screw the dizzy round 5-10 degrees extra and take it for a gentle cruise dont go full throttle just see what it does to the cruise area and see if she smooths out bet it helps a lot be a good test to show you how much to add down low

 

[96SEN8R]

haha damn oh well. yours has a throttle body yeah? what do they cost, as the manifolds are around 900 i think. then i also need the filter for on top. any other costs i need to look at?



yeah i might try raise the timing a little there. nah no aldl yet. hoping it comes soon and then i can work out whats going on

1050 for manifold drilled for efi, 700ish for tb from efi hardware( dont go anywhere else for a tb) and extreme flow 14x3" 21/2 inch dropbase filter and assembly 300ish, then manifold gasket.. coolent and oil, should cost 2.2-2.3 if ya do it yaself
Yeh i got a 1000cfm tb

 

[eaton v8]

hey can you put your cam spec sheet up it all sound very familiar to me. every thing down to the wade cam. the only way mine got better is when i put the heltec in and got it tuned. it still jerks but only just really faint. if it is the same cam i think the roots is the way to get rid of the problem down low. but thats if its the same cam

 

[ari666]

what are ya cam specs bro? those plugs look fine to me. sadly i cant help with EFI much, but "juggling" (the car seems to jolt about a bit) when going in a straight line would suggest a lean condition with cabry, but i am sure your O2 would sort that out. you checked for vacuume leaks right? a leaky manifold will throw you alls orts of weird problems like what your facing

dont mess around with manifolds drilled for efi please!?!? just got a manifold for carby. you will use a bucket more fuel, but hey, at least we could work out whats up with your ride