Low dyno #'s on new head/cam setup....suggestions?
02-14-2004, 06:50 PM
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Low dyno #'s on new head/cam setup....suggestions? Hey guys. New to the forums here. I actually posted this in the Truck Performance forum, but figure I might have decent luck in here too:
Hello all. First post. I've been pondering on buying an f-body here recently, so I've been lurking these forums. My problem now is with my father-in-law's truck. It's been a project of our for the last year or so. 90 GMC short bed. I'll post pics later. He got a decent deal on a Jasper crate small block that we put in. Both of us are somewhat new to engine building, so you'll have to pardon my lack of knowledge. Upgrades on the engine are shorty headers with true duals with Flows. Here's the newest upgrades we just put on:
Edelbrock Performer Heads (350-60859) - Int. port vol - 165cc, Int. valve size - 2.02", max valve lift - .575".
Edelbrock cam - 244/264, .398/.442
Edelbrock Throttle Body Injection System (350-3502).
Now, this setup was recomended to us. Was a "power" package Edelbrock pushes. They sent us a prom chip that we put in. It sounds real nice and runs very smooth. Thought it was down a little on power, so we had it dynoed.
We got a best run of only 228 rwhp and 296 max torque at 4800 rpm. Fell on it's butt after that. This is through stock gearing on an M5.
I know the cam doesn't have a huge lift on it, but I would have thought that 300 hp would have been doable with this setup. Airfuel throughout the run was around 12.1.
Hehe....maybe we just chose a crappy setup. What do you think. I'm not going to post a link to Edelbrock's site, but I included the part numbers if you need more info.
Thanks!!
DAVE
Edelbrock Performer Heads (350-60859) - Int. port vol - 165cc, Int. valve size - 2.02", max valve lift - .575".
Edelbrock cam - 244/264, .398/.442
Edelbrock Throttle Body Injection System (350-3502).
Now, this setup was recomended to us. Was a "power" package Edelbrock pushes. They sent us a prom chip that we put in. It sounds real nice and runs very smooth. Thought it was down a little on power, so we had it dynoed.
We got a best run of only 228 rwhp and 296 max torque at 4800 rpm. Fell on it's butt after that. This is through stock gearing on an M5.
I know the cam doesn't have a huge lift on it, but I would have thought that 300 hp would have been doable with this setup. Airfuel throughout the run was around 12.1.
Hehe....maybe we just chose a crappy setup. What do you think. I'm not going to post a link to Edelbrock's site, but I included the part numbers if you need more info.
Thanks!!
DAVE
02-15-2004, 06:01 AM
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I don't know what your expectations were, but the original TBI engine in your truck would probably only dyno at 180-190 RWHP, so a gain of 20+% may be all that you should expect. 300 RWHP would require more compression as well as more cam.
02-15-2004, 06:39 AM
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that sounds about normal for a sbc withh those mods.that cam you chose will peak at around 4800rpms.that's a pretty small cam,even compared to a stock ls1 cam.
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02-15-2004, 01:07 PM
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Thanks for the input. Sounds like it's probably set up right then, just chose a few lower end parts performance-wise. Any recommendations on a cam for this? I don't want to make the same mistake twice.
02-15-2004, 01:08 PM
#9
www.thirdgen.org has a TBI section that is pretty sharp. They maybe able to offer more help on the TBI stuff than we can.
The Edelbrock TBI intake isn't all that great. Most people hard core TBI er's won't use it and go with a carb intake with an adapter and put a Holley 670 TBI on it. This can work every well with a stock GM computer with a new chip.
Are those the advertised cam specs? Often a used LT1 cam works great in a 305 and good in a 350 TBI application. I doubt the Edelbrock cam is optimal.
Might talk Edelbrock and see what they say about the power because it seems pretty low.
What's the fuel pressure?
What size injectors?
Did ya try a TB spacer?
Was the TB ported?
The Edelbrock TBI intake isn't all that great. Most people hard core TBI er's won't use it and go with a carb intake with an adapter and put a Holley 670 TBI on it. This can work every well with a stock GM computer with a new chip.
Are those the advertised cam specs? Often a used LT1 cam works great in a 305 and good in a 350 TBI application. I doubt the Edelbrock cam is optimal.
Might talk Edelbrock and see what they say about the power because it seems pretty low.
What's the fuel pressure?
What size injectors?
Did ya try a TB spacer?
Was the TB ported?
02-15-2004, 09:33 PM
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The part I would look into is the power band falling off after 4800.
Are the springs correct?
Was the cam degreed in?
Like everyone is basiclly saying these T/B motors where not top end screamers.
I'd agree there should me some more in it?
Edit; Ever though of running a different fuel system as well?
Are the springs correct?
Was the cam degreed in?
Like everyone is basiclly saying these T/B motors where not top end screamers.
I'd agree there should me some more in it?
Edit; Ever though of running a different fuel system as well?
Last edited by wrencher; 02-15-2004 at 09:39 PM.
