1GGTE: HKS cams installed car feels like NA

[cultus]

Ok, I've spent the whole afternoon installing the HKS 272 8.1mm cams. By right it shouldn't have taken so long, but the rain caused some delay and the allen key bolts on the adjustable pulley were hitting the timing mark plate. So use back the ori cam gears.

Now the car feels like a big NA car !?!? Boost comes in at late 4+k, but there is no turbo punch. Just smooth ( & not impressive ) acceleration even under boost (showing .4/.5). Like driving an old beemer or merc. Before the change the cams when I press the gas pedal, boost immediately builds up to about .7 ( I am using a single RB25 turbine )

I double checked the timing mark on the cam gears by turning the crank with a screwdriver in piston 1 method. Piston 1 all the way up, both inlet and exhaust line up perfectly. Distributor I did markings as well. The spark plug color is the same as before, slightly brownish. The car couldn't idle at first, must throttle a bit so I adjusted the idling screw.

Ignition timing? Or I need to reset ECU? I am kicking myself for not installing the NA cams instead.

Anybody encounter this before? Please help. Thank you

[oldcorollas]

too much overlap and blowing all the boost out of cylinder?
272's should be good for 4-5000 starting point no?

maybe need to check the actual lift/timing as the cams may not be dialed into the factory marks... reduce overlap and see what happens

[cultus]

Even above 5k rpm, with the .5 boost, still feels like NA, no punch at all.
Yeah I think you're right, oldcorollas, I guess I have to allocate this Saturday afternoon for swapping the cams By the way it is going now, don't think the adjustables will do the trick

[oldcorollas]

272 is not small for turbo cams...

what rpm range were you expecting?

have the mixtures/timing requirements changed? you might be seeing less boost, but getting more air in, and running it lean? or losing too much out exhaust, and running rich?

chuck it on dyno to get AFR's, check how much actual overlap there is.... or chuck stock exhaust cam back in?

edit: i'm sure the 1G guys can give mroe specific advice.. i'm just filling in until they get here

[GTZLevin]

semi off topic...

what sort of setup would you recommend 272's to be used for? 4agte?

[cultus]

I was already expecting the boost to come in later but didn't see this coming ...

I have seen shops here ( with dyno ) played with the car weight to show the customers gain in power after installing their stuffs. Moreover, I don't have the spare budget after the recent condo handover.

The friend who borrowed me the torque wrench, has a wide band for A/F, and I can get hold of a timing light for this weekend, the adjustable will be machined by then. Will try to minimize the overlap, if all fail then swap to NA cams.

Appreciate your input. thank you

[oldcorollas]

sound slike you are on the rigth track.. see if you can find some lobe angle seperations that others have used.... and see what ppl like 6boost are using for their cams...

GTZ... i'm not totally sure on the specifics, bu thaving boosted shifts the rom range higher...

it will come on later than in NA, because you are losing more charge during overlap for higher in the rev range.. but will continue to a higher top end,

so say your NA cams are 3000-7000.. that might be 4000 or 4500 - 8500 with FI...

if in doubt, most cams have been tried in most popular engines.. so is just a matter of comparing ppls setups.. (and what they did right/wrong)

[Dieseltrain]

Try getting some Adj cam gears and Dialling them in to help... This should help bring boost back on earlier.

[lexsmaz]

Have you checked the valve clearances with the new cams .. & as you said you need to check the ignition timing ...

[Norbie]

You didn't mention anything about tuning your aftermarket ECU on a dyno after installing your radically different cams. You're not expecting the stock ECU to cope with this setup I hope? AFR's and timing curve will need to be significantly altered.

[cultus]

Standard ECU ... naive to think that it could, will check A/F this weekend. Thinking if A/F is less than 13.5, at 10 degrees, I will proceed with installing the adjustables to minimize overlap. If more than that, abandon hi cam project, swap out and use the NA cams.

[Kyosho]

Standard ECU ... naive to think that it could, will check A/F this weekend. Thinking if A/F is less than 13.5, at 10 degrees, I will proceed with installing the adjustables to minimize overlap. If more than that, abandon hi cam project, swap out and use the NA cams.

Or go spend money on an aftermarket ECU...

[Pube]

I recken remove the HKS cams and sell them rather than go aftermarket ecu. Im sure they would fetch a decent price.

[DigitalPho3nix]

Standard ECU ... naive to think that it could, will check A/F this weekend. Thinking if A/F is less than 13.5, at 10 degrees, I will proceed with installing the adjustables to minimize overlap. If more than that, abandon hi cam project, swap out and use the NA cams.

You in all likelyhood need an aftermarket ECU to properly and reliably run those cams. Even in N/A engines, your looking at a new ECU when you get past the 272deg mark.

Are you running large enough injectors?

[SillyCarS]

First things first

Sounds like you are a bit naive and we all were at some stage

I would suggest you stop driving it before disaster strikes and take the above advice, get an after market comp, adjustable cam gears and a propper tune. It may cost a bit in the short term but reliable power is worth more in the long run than a string of blown engines.

PM someone like 6boost hes always more than willing to help. Just make sure you outline exactly what you want from your engine and how much you have to spend.