Share Posted 07/08/20 07:29 AM Hey guys, I'm just going through the last few bits and pieces and giving them a good clean and inspection before screwing it all together next week. And I have noticed that the lower manifold is still configured with the broadband dual ports, while the upgrade upper plenum is opened up to huge single oval ports. Am I going to benefit from opening up and match porting the lower to suit? Seems like it could cause quit some restrictions on full boost to me? Cheers Ken Link to post Share on other sites
Share Posted 07/08/20 07:41 AM I think it would make a difference but I haven't measured the difference. Maybe one day I will do a back to back as I'm interested as well. I didn't mod the lower plenum when I installed the plaz top half. Link to post Share on other sites
Share Posted 07/08/20 07:48 AM If you can comfortably push to 1000hp with the lower half still in-tact, I'd say it's not worth bothering to do other than to make your tuners life easier with regard to intake flow. Link to post Share on other sites
Author Share Posted 07/08/20 07:50 AM I'm just looking at the different options available and I have to think that the factory lower is going to cause some significant restrictions if not opened up at least in the lower part of the port where it has a bottle neck at the end of the machining. If not opened up, at least a blending will make big difference imo? I'm looking at all the small things now, as the rest of the engine is completely blueprinted etc. If it helps anywhere within the range then it's free power! Top end numbers are not my concern now, I can get bigger numbers with boost and timing Link to post Share on other sites
Share Posted 07/08/20 08:05 AM Port matching, porting, smoothing and blending etc is time consuming but it makes a difference. Fasterproms swears by it. Link to post Share on other sites
Author Share Posted 07/08/20 08:22 AM Yeah I tend to agree, peak numbers are just that. Through my experience with ford V8's By blueprinting and match porting/blending of airways I could get a e7te headed EF XR8 with ho manifold to whip the pants off the same model car equipped with GT 40p heads, a cam and gears to suit and lower geared manual transmission. On the dyno the other guy couldn't wait to give me a run (with his whopping 35hp difference!) But even with a passenger and full tank, I continually drove away from him every time... I noticed the huge difference on the dyno with my torque curve. So that is what I'm trying to find within the Barra turbo, cos we all know about the bolt on/tunable power they make. Any extra torque for nothing should never be turned down 1 Link to post Share on other sites
Share Posted 07/08/20 08:49 AM but it isn't nothing... it's a lot of work for a tiny amount of extra torque at low revs. Link to post Share on other sites
Author Share Posted 07/08/20 08:56 AM Well, I'm locked down with the current situation. I have a shed full of the best tools and still waiting on delivery of the engine and new turbo etc before I can screw it all together. It's not going to cost me anything, and if it doesn't make too much difference once done at least the Mrs won't be sick of me pacing around the house looking for someone to annoy! Link to post Share on other sites
Share Posted 07/08/20 09:03 AM go your hardest then, but be sure to measure flow before and after to see if you've actually made a difference Link to post Share on other sites
Share Posted 07/08/20 10:34 AM 1 hour ago, k31th said: go your hardest then Agreed 1 hour ago, k31th said: be sure to measure flow before and after to see if you've actually made a difference Kinda hard to do once you've already busted out the grinder. I'll do it though and report back in 12 months when conditions are the same. Also I found the oil pump housing from ages ago. It was in a basket with some fishing gear for some reason. Link to post Share on other sites
Share Posted 07/08/20 10:49 AM Better than bolting it all up and always looking at it and wishing you had done it Link to post Share on other sites
Share Posted 08/08/20 08:44 AM I agree, you would be always thinking 'what if I'd ...' you have the time and equipment just do it! even if it adds only 1kw it's better than watching tv! Link to post Share on other sites
