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x-post from Rennlist since not everyone follows both
I wanted to share the results of what has been almost a 2 year rebuild journey. When I was going through this build it was hard to find detailed build details along with concrete dyno results. My hope is this thread will help others who have similar goals to mine. In short, I wanted an issue free car that I could street drive on the rare occasions I don't need to have a car seat. I also wanted to be able to drive this car the 1-2 hours to the various local so-cal tracks, knock out a fun track day, and then drive home. Through working with some truly amazing partners I think I have arrived at just that, though I'm sure this car will never be "done". Limiting factor at the moment is fuel, we simply maxed out the single Walbro 450. To go further I'd also have to move to a stiffer wastegate spring. I don't think a single plate clutch is going to hold much beyond where I am now so I don't see myself going for more power anytime soon.
The dyno used was a Mainline, these typically are considered a conservative dyno. Maybe someday I'll go to an open dyno day to cross-reference with a mustang or dynojet.
Here are the 91 and 100 octane graphs. While the peak isn't much different there is a significant jump in the mid-range on 100.
· Fuel
o Single Walbro 450 mounted in factory basket using Radium adapter sleeve
o 8an PTFE feed fully fire-sleeved
o Aeromotive 8an 10-micron cellulose filter
o Dual Radium 8an fuel dampers
o Earls 8an submersible check valve mounted just under top-hat bulkhead
Great build but why why why did you put those terrible head studs back into that car. I hate those head studs passionately.
Headstuds are way overblown and overhyped especially for guys not planning building a 2bar 1/4mile motor. We've run stock studs on both my 3.8 and my 4.0 builds with ZERO issues over several hundred hard track hours and chose to stick with them for a reason, saving money is not one of them. I have no inclination to get into the studs debate but rest assured if the builder knows what they are doing utilizing the correct procedures, they are not an issue.
I see, he must have cranked them down a bit tighter as well. Still, why not grab some BBi 10mm or something like that at the minimum? From experience, as it is well known that I blew my cylinder head off with a Protomotive tune on 18g billets, why not give yourself more headroom?
I see, he must have cranked them down a bit tighter as well. Still, why not grab some BBi 10mm or something like that at the minimum? From experience, as it is well known that I blew my cylinder head off with a Protomotive tune on 18g billets, why not give yourself more headroom?
Who is to say BBi studs or other aftermarket studs are any better? Oftentimes only those that sell them or those repeating the gospel. For many applications, simply not necessary if you use the proven procedures which race builders oftentimes hold close to their vest. Always let your builder make the call for what is best for your use. One size does not fit all.
To give you an idea, every part of my build was evaluated including, crankshaft, IMS, bearings, camshafts, valve train, and head studs included. Every part was evaluated and selected with respect to attaining the performance goal in mind. There were specific reasons 12mm studs or 10mm aftermarket studs were NOT chosen. We could have done so as we have CNC machining capability which was used to machine the case for the 106mm pistons and liners. Doing studs would have been easy.
Who is to say BBi studs or other aftermarket studs are any better?
I am qualified to say that because I lifted a head with them. BBi and other builders are qualified to say that because they tested them vs their new setup. I imagine you guys are fine because you are only running 700 or so, but still I think you should have done them, not worth the risk. To conclude I'm glad you are happy with them, but I'll probably give you a hard time if I see you.
To give you an idea, every part of my build was evaluated including, crankshaft, IMS, bearings, camshafts, valve train, and head studs included. Every part was evaluated and selected with respect to attaining the performance goal in mind. There were specific reasons 12mm studs or 10mm aftermarket studs were NOT chosen. We could have done so as we have CNC machining capability which was used to machine the case for the 106mm pistons and liners. Doing studs would have been easy.
Really? I would love to hear more about your research as to why u didn't go with a bigger or better stud.
Really? I would love to hear more about your research as to why u didn't go with a bigger or better stud.
Like I said in my post above, I have no inclination to get into the stud debate. There is really no point to it Joe. If guys think OEM studs are garbage and prefer aftermarket studs, that's their prerogative and I'm happy for them. We've found other solutions. I'll leave it at that....
It looks like you've proven that they can be used safely if you increase displacement and run lower boost. Would I do it? No. I measured them to be 9mm inside of the threads. Certainly you shouldn't use them if you are running 1.5 bar+. I think it is a really shaky argument to make that they are better than some aftermarket. But anyway a global pandemic is spreading, the economy is collapsing, and like 1% of the people I know could die so I am going to go find something else to do.
Head studs are an engineered solution for the metzger engine as it was put in the car. There is a lot going on there with differential thermal expansion and the forces placed on the head gasket and the head itself. Stronger/stiffer is not necessarily better. Granted if you are pushing 2 bar and some crazy 1200 hp you may need them to survive. But the same super studs installed in a 600 hp motor may have negative effects like reduced head gasket life or cracking ???? In my job I bolt alot of high temperature aluminum together and try to make it last. There is a lot of science to doing it right