Sick280zx Posted February 15, 2012 Share Posted February 15, 2012 Well I did a head swap to up my compression a bit and put a 270/280 with the 112° lsa schniender cam in. Now heres my luck the efi wiring harness stopped sending fire to the injectors and now switching to dual weber 32/36 dgv's. Just wondering if its gonna act like a road racing cam and have little to no power for "semi normal street driving" Thanks for the help! Quote Link to comment Share on other sites More sharing options...
ram75280z Posted February 18, 2012 Share Posted February 18, 2012 (edited) It will work just fine, it will just have to be tuned differently than the 'carb' cam. Having a wider LSA(Lobe Separation Angle) simply reduces overlap. Most fuel injection systems require vacuum to control the fuel pressure regulator. Otherwise they will over-fuel at small throttle openings, low RPMs and idle, until you reach the bottom end of the cams operating range where vacuum will become 'normal'. With your cam that point would be roughly 3000rpm. Even if you got the timming right, performance would be very average below that rpm because you wouldn't be able to dial out the extra fuel. You didn't have that problem with FI because you had the right cam for it. The other effect of a wide LSA is the rearrangement of the torque curve. Wide LSA cams will produce a plateau shaped curve(slightly better lower and upper rpm), going sharply upward toward lower end of the cams operating range, 3000rpm with your cam, stay relatively flat until peak, 6500rpm again for you, down after that. Narrow LSA produce a mountain shaped curve(better mid-range power), going sharply upward toward peak torque RPM, around roughly 4500rpm with your cam, and sharply downward toward redline. So when your cam with the two different LSAs are compared to each other: Wide LSA= more power 1000-3000rpm, and 5000-7000rpm Narrow LSA= more power 3000-5000rpm There's really been a change in how cams are looked at in the automotive world. A wide LSA cam is better for all applications; street or race, carbed or FI. The only exception being someone who wants/has an automatic(where mid-range power is much more important) and/or wants a 'mean' sounding idle. So, with the carbs you have now, you will tune for that plateau instead of the big bump in the mid-range. Get a wide band o2 setup because everyone elses setup with those carbs(any carbs really) aren't going to work as well for you. I can't help you with those carb settings, because I'm not familliar with that model. But, if they're setup for a stock l28, they won't be too far off. All you will probably need to do is add a little fuel in the full throttle 'circuit', and a slighty smaller accelerator(pump or enrichment) 'circuit' to make it work. Edited February 19, 2012 by ram75280z Quote Link to comment Share on other sites More sharing options...
Sick280zx Posted February 19, 2012 Author Share Posted February 19, 2012 Thanks a bunch man just got the sucker to start up today it should run well like you said once I get it tuned right! Quote Link to comment Share on other sites More sharing options...
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