Slow to built RPM's

[DailyDrifter]

What would cause the engine to be slow to build up RPM's? The tune is good, but the car doesnt want to rev up when under a load. It also sounds like the exhaust is comming out the intake valves (BTW new springs were installed 2 weeks ago). I can only get it to rev up to 4300 rpms and it has no power. The cam is 212-224 roller. Boost is set at 20 psi. Coil and IGN module are good, No MAF. Some more info in sig. Also injector duty cycle comes in slow and goes to 60% at 4150 RPM. It has to be something mechanical, because I connected the stock ECU in and it still did the same shannanigans Any suggestions would help out greatly

Thanks, Dave

 

[bison]

Wrong springs, wrong installed height, coil bind, excssive pre-load. You need a 3600 stall (at least) for that cam to work well on a 3.8 and it too much cam for that turbo imo. The 3500 may be ok. I have comp 941 springs in mine

 

[bmackinnon]

edit.... nevermind.... read the sig and I'm probably off base....

 

[DailyDrifter]

Wrong springs, wrong installed height, coil bind, excssive pre-load. You need a 3600 stall (at least) for that cam to work well on a 3.8 and it too much cam for that turbo imo. The 3500 may be ok. I have comp 941 springs in mine

Thanks Bison. I had a reputable shop put the new springs in. I guess I was given bad advice when I was selecting a cam . I think its time to part the project out I dont have the money for a new cam, nor do I have the facilities to install it. Thanks again bud

 

[bison]

Thanks Bison. I had a reputable shop put the new springs in. I guess I was given bad advice when I was selecting a cam . I think its time to part the project out I dont have the money for a new cam, nor do I have the facilities to install it. Thanks again bud

Dont part it out. The cam will work its just not optimum for the combo. It will make plenty of power over 5200rpm. Post the total lift at the valve and the spring part #. Then we can see if your near coil bind on paper. You need to check the installed height also. Fwiw i have .496 lift at the valve and my springs are installed at 1.700 and it revs to 6000 with no problem. Also post the overlap degrees so we can see whether or not you should advance it a couple degrees or not.

 

[DailyDrifter]

I took a pic of the cam card. Hope this helps, Thanks again. I really dont want to part it out but the body is crap and I wouldnt get sh!t for it as a complete car. I would like to get one nasty WOT run out of it though. BTW I cont find the part number for the Springs.