I have a gt 40 intake going to bore it out to 70mm someone said that will be safe.
1. do you think i can bore it out to a 75mm
2. how far in to you go to be safe in boring it out like the depth.
thanks for the help guys you have been great in my other posts.
Is it a real GT40 or is it an Explorer? Also, if it is an exploder, what year, as the EGR may make a difference too. Any way, the bolts through the neck will decide how wide you can go in as you widen the throat. Tmoss has a site that answers how to measure and do it right. It is one of his many porting documents.
can anyone else help out I can't find info on the tmoss site, he talks a lot about porting the lower, I just want to know how much I can bore out the top intake to fit a 75mm tb can I go 75mm or just go 70mm
Here is another site with the same info, maybe more. I spent a lot of reading time here. I wish all of jrichker's regular help posts were all in one spot too. Between my print outs from the two gurus, my Chilton's manual seems generic! http://tmoss.efidynotuning.com/
Sounds like you don't have a TB already, just buy a 65mm.
In a combination consisting of an explorer gt40 intake, there probably isn't any power to be had going larger anyway.
If Kenne bells site is to be trusted, even when they added a 70 over a 65 drawing through it with a supercharger it only added 2hp.
I think you can even convert the 65 from an explorer to work. Making it extremely cheap.
331 stroker supercharged, I have the 75 and when I put it on the stock one it is a lot bigger just seeing if you could bore it out. or maybe it doesn't matter if it is that much bigger. Does it matter? wasn't looking for hp just making sure it would work either way
If you are running the lower intake on that setup unported...just run the parts as is. Your bottleneck will be the lower.
To answer your question, you can enlarge the opening. basically take the gasket with a 75mm opening and trace it on the explorer intake. Then use a dremel to round the transition into the intake over so the mating area is all seamless. Don't go crazy, just blend it in.
As for what size TB, it's tough to say. You didn't give enough details on the combo.