New in Springfield, MO
 

I have a 1993 Miata which is stock. Bought in 2012 and have been doing minor repairs and up keep plus enjoying driving. Am currently doing some body work to remove rust in rear quarter panels. I would like to convert to an LS1 engine. I am retired and have plenty of time but not a great deal of money so I will be proceeding slowly. I have thought I would like to use Boss Frog Conversion but would like to hear any comments. Will post some pictures of my current work in next day or two.

welcome! what is your end power goal? I purchased a boss frog kit and was going to use it till I found out that it didn't fit my 1 3/4 diameter long tubes. But Not very many people use those due to the price @ $1200. The more budget friendly sanderson headers fit the boss frog kit and cost around $3-400, but are only 1 1/2 diameter. If you're sticking to a stock motor and looking for stock power they will be fine.

+1 ^ and welcome! Seems like your part of the world is the hot spot for builds these days!

Would love to see your pics and know more about the car and goals. I assume the reason you want to go BF is to save the tunnel work? Valid reason for sure but if your goals are modest you might consider a Ford as they are even more straight forward to build, cheaper and sound much better.

So many options it is hard to know the best course but you have come to the right place for sure. Check out the FAQs and give us an idea of what you want to do with it, your capabilities and shop set up and of course the budget.

Thanks for the intro thread I'm looking forward to getting to know you!

???? Jim the LS guy? Is that really you?:p

OP-Welcome to the forum!

LOL what can I say I'm bi-manufactural and love them both!

Limited Skills
 

I am leaning toward the BF conversion because I have very minimal welding skills. I have always had a soft spot for GM motors and like the cool factor of having a Vette engine in my Miata. As for facilities, I will be working in rear of one side of my current garage. Not a huge space but hopefully sufficient. I do have a limited budget so I may need to consider Ford option just for cost. My goal is to have a cool car to drive around in nice weather and do a few local car shows. I have never had a self built hot rod.

LOL for what it's worth that description describes me to a T before I started! I'd never welded anything in my life, my garage is 10 x 20 and my budget was - well 2 years later I still owe 2500 on it!

I know it's easy for me to sit here and say this as after the fact, and I truly understand exactly why you are skeptical about your skills, but my hand was shaking so hard the first time I pulled the trigger on the borrowed welder that I nearly burned a hole in my boot and if I can do it you can do it better!

I doubt you would find anyone that feels BF kit is better than the V8R for any reason. The only critical structural weld you need to do happens at the diff mount and I believe it's the same in both kits anyway. For that just tack weld it and take the sub frame to a welding shop if you are concerned.

To be clear I am not saying the BF kit is bad or you shouldn't use it, I'm just saying the welding is not that big of deal and IMO not really a good reason on it's own to use it.

I will say though, the BF subframe is VERY solidly built. I would have zero reserves about using one if it suited my needs.

Welcome from another midwest guy. I think we are going to have enough people before long to Justify a meet....seems like a new midwest guy around here all the time. I'll actually be in Rolla Mo(just up the road from you) this weekend.

In my honest opinion, I think both boss frog and V8R subframes are good options, and as previously stated, I think a big deciding factor is if you are wanting to run some longtubes. I knew I did, and I knew that was about the only thing I was willing to blow my load on so I went V8R.

Don't worry about the welding thing....thats what a grinder is for....Check out some of my bad welds in my build thread. What is it that Edison said? "I have not failed, I've just found 10,000 ways that won't work".

I think charchi may be onto something with the SBF suggestion. Parts are considerably cheaper, and from what I can tell a little easier to get into these cars. Couple that with the fact that a mildly built SBF will make comparable power to a stock LS engine.