What is wrong with my engine combo?

[Morton]

From the reading and research I've been doing, a high-rise manifold will be down on power versus a low-rise manifold, right up 'till after 5500rpm, at which point they start to feed those big chunks of air in nice and fast. 8.8:1 compression is fairly low, too. You could probably get away with 10:1 with 98 octane, and will see much better results.

Do you have dyno charts you could scan/photograph and post up? I'd be curious to see how the torque curve has moved with the tp hi-rise manifold

 

[sir355]

Go see Leon at awesome auto, clovely park near mitsubishi. He will let you know wats goin on. Have you done anything to the heads? You should still have seen a slight increase with that manifold, regardless of the comp. I'm running 9-1 and the harrop single and i saw big gains. I'm using the crane 286. I suggest putting a crane or msd ignition on it and change your cats.

 

[burnz]

just wondering is the cam dialed in ??

and it's been know that some faulty cam dowle hole's are not allways true/accurette.

and 8.8 comp woud be nice for P/D.

 

[andrewownsavp]

Yeah man sounds over manifolded and over cammed it happens aye see so many people make this mistake.

I used the Starr manifold and crane 284 cam 222deg cam and its got 9.1 comp and a haltech with dyno tune got 210rwkw out of it in a manual.

But yes i seen people put the active manifolds on with injection perfection 1000cfm 4 barrel on with that exact cam and have a 100hp shot nitrous set up and just push 200rwkw with gas so yeah somethings work well with each other on the 5ltr and some dont.

 

[RVK 355]

something aint rite, even with the low comp it shouldnt have really lost any power by doin a simple manifold swap.

was there anything else you changed at the same time!

 

[andrewownsavp]

yeah sounds strange aye there still power adders i suppose they
will do something maybe the tune isint right?

 

[Morton]

edit: disregard this

 

[Immortality]

something aint rite, even with the low comp it shouldnt have really lost any power by doin a simple manifold swap.

was there anything else you changed at the same time!

i agree, thats why i asked where it's making it's peak power. if they haven't increased the rev limit it may well be the limiter is kicking in before the cam has a real chance to work. with a tight LSA and duration it has it needs to rev.

 

[sir355]

the rev limit should have been reset with the crow package/ memcal.
In my original build i had it done with the crow stage 3 kit, standard manifold, and she made good power, i then changed to the crane 286 cam and it increased again, then i added the harrop single plane and holley 1000 tb and had it tuned and it made 350 rwhp. So something is amiss with yours.

 

[96SEN8R]

Thanks for all the feed back fellers. Nar i didnt get any other mods done at the same time. All these figures for my power were done on a mainline dyno so will be reading lower then dyno dynamics. The manifold went on by itself. When i first got the cam put in the power gain was only 4 rwkw. that was with the starr manifold. So i was worried that the cam wasnt dialed in properly, but the guy that did it does heaps of cams so i wouldnt think so. What would other symptoms of this be? Id whould be pretty pricey to get another mechanic to check wouldnt it? When it didnt make power, he told me my manifold wasnt flowing well enough so that is why i put the tp on. Im going to put 10.1 pistons in and get the heads flowing a bit better and see how i go. Might take a bit to save though, but ill keep you informed. Thanks again