I've got an RS-Ltd with M45 @ 5 psi, so THEORETICALLY, it could be up to about 180 bhp, although I suspect its slightly less TBH. (Steve at MX5motors drove mine and he said it felt on par with 175 bhp '5s that he'd driven).
My old car was a 98-spec JDM Integra Type-R, on paper 197 bhp / 1090 kg.
I'll be honest, I wouldnt fancy my chances in a straight line against the teg. Although there wouldn't be a huge amount in it, but I should think the teg would have it in the end, particularly above about 80 mph. My ITR used to pull up to 150 mph on the clocks real easy. The ITR was about a similar pace to a stock CTR EP3, the latter being heavier but with a better gearbox and stronger engine.
You'd definitely need well over 200 bhp in an MX5 to be significantly faster IMO especially from a rolling start, assuming the CTR driver is in the right gear!
One thing where my '5 is better than the ITR is torque, it definitely has more low down, and feels a faster car most of the time, but feelings can be deceptive! That said though, if both cars were in 5th on the motorway at 60ish and both planted the throttle I'd expect the '5 to pull away, as you need to be doing 100 mph in 5th before the ITR comes on cam.
Problem with Type-Rs is people dont drive them right. You absolutely have to cane the nuts off it to get good performance. Its a very jekyll and hyde car. They feel quite ordinary when off cam. Start in the wrong gear in a Type-R and you've already lost the battle. Thus, in give or take situations, the '5 would be faster. Around a track, it'll be a lot closer.
I'd like to compare my car in a drag with a Type-R just to see how it panned out. My suspicion is a properly driven one should be slightly faster. Recently I was out on a run, and noticed that a slightly modified Fiesta ST with breathing mods was about on par with my '5, the owner reckoned it was about 165 bhp. A Type-R would surely be slightly quicker than that.
All of this ignores the fact that the '5 is a much more fun car. I'd rate my RS-Ltd even with its relatively mild state of tune as a SIGNIFICANTLY more fun car than the ITR. It offers more feedback, more nimble handling, a more "kart like" experience, more torque, conveys speed better, feels faster and just puts a bigger grin on your face. Add to that the fact that the CTR (I have driven one) felt noticeably more boring than the ITR did, and for me, there's just no comparison as a drivers car. The CTR didn't sound as good as the ITR, had really dodgy electronic power steering, suffered from poor traction (no LSD), has an MPV like driving position (albeit good and comfortable) and just didnt feel special in the same way as the ITR.
Sorry for going on a bit, but I really dont feel like you can compare a '5 to any Type-R. To do so is kind of missing the point, the '5 isn't and never will be a straight line car in my books. For me, the '5 is a bona fide sports car designed that way from the ground up. Type-R's are really just hatchbacks which are set up as cheap track cars. They are good on track, but the things that make them so good as track cars, make them compromised for the road, they feel ordinary when not pressing on, and when you do, they have enough pace to destroy your license. The thrills that a '5 offers are so much more accessible.