61mm TB: Install Notes & Driving Impressions

[TonyB]

I finally decided to do this mod, and I'm quite happy with the results. While I've heard that this is a 30 min install, and it can be, I took nearly 1.5 hours.

First, I got this unit from Peter at M7. He retails them for $399.95. This is for both the MC and the MCS. It came well-packaged: wrapped in bubble wrap, and the box filled with popcorn type foam. Even though the unit arrived very clean, prior to install, I shot it with some brake cleaner and wiped her clean. It took-off a thin grey layer of film, probably from the fab process.

I'm a little anal about stuff going on clean. While I suppose this could be done in 20 minutes if it were a race, I also wanted to clean-up the tubes (from air filter and the snorkle). They had some grime in them, and I spent some time wiping them down. In total, a good 15-20 minutes was spent cleaning. No problem on a beautiful Sunday afternoon...

Oh, before starting all of this, I disco'd the battery.

Once I got the stock TB out, I saw what Peter meant about getting a Dremel tool ready. While this procedure is not necessary, I find it to be. At the base where the TB mounts, there is a down tube feeding the SC. Inside that opening, there is some plastic-like material sandwiched that had oozed and hardened, making for a smaller hole and a not so smooth inlet. I sprayed a clean hand rag with WD-40 an shoved it down into that pipe. I then proceeded to Dremel that material out until I had a larger opening, that was flush and smooth. I had a shop vac ready and sucked-out all the debris that I could, while leaving the rag in place. I then carefully removed the rag, and used the vacuum again. This took another 15 to 20 minutes...

If you don't want to re-use the hose clamp to the TB, have one ready, and the right size. When doing this install, I noticed that the pipe coming up to the intercooler was loose! The crimp clamp would just spin as I flicked it with my finger and the hose was quite loose on the intercooler. I did not have the right size clamp. So, I used a bigger one, tightened it down and cut-off the extra length. That was another 15 or so unplanned minutes. Something to look for if you do this mod...

If there is such as thing as the most difficult part, it woud be the vapor line. I had a fairly difficult time putting her back on, but nothing major. The four 10 mm screws holding the TB down are not torqued that tight. Keep that in mind when tightening...

Once installed, and everything was snugged-up, I then reconnected the battery and fired her up, only after making sure all of my tools were out of the engine area. I learned that lesson when I was a kid

Everything sounded fine, so it was time to take her for a spin on these canyon roads. First impression is the throttle response. It is more lively. When I had a chance to open her up, it pulls more. I can feel it, more so beyond 4k. As always no dyno guys. If so, I would title the thread accordingly. But, from previous accounts that I have read, I have seen 5hp min, to 7hp max, for a pullied MCS. I also saw a figure of 4.3 for the MCS, but that might have been w/o a pulley...

I'll just call it 5hp for now... Some will say that 400 bucks for 5hp is not that good. Indeed there are better bangs for one's buck out there. But, it ain't bad either. Some will pay twice this price for a catback that make this, or less. There is the appearance and sound factor though that are not considerations here though.

Still looking for the ideal header...

[obehave]

Excellent again Tony. I'd good rep you but I'm being told I have to be more "giving" in my distribution of good will.
5HP on it's own may not be much but since you've done most of the significant HP mods the small gainers will be it,
At least until you pony up big bucks. Cam and heads or that big turbo kit that's in the works. Then of course you'll need a stronger clutch

[TonyB]

Thank you obe. I would much rather stick with a SC, as opposed to a turbo, at least as it stands now. The twin screw type that is nearing completion has me thinking quite a bit...

Yes, the clutch would need to go. Then do the flywheel, and possibly an LSD while in there... I really need to do something with the brakes fairly soon. I should be pushing 220hp now.

I'm going to continue to hold-off on my straight pipe SuperTrapp project until I see what unfolds with that SC. And with that, I will put the header on hold also.

The cam and heads are items that I would love to get next, but that is probably not a DIY...

[LuckyRVA]

Great write up. Thanks for the info!


-Jason

[Andy@Ross-Tech.com]

Good writeup! How did the throttle body look? Did it have a metal band holding it together? If/when I do a bigger TB, I'll do some before and after testing with the air pressure between the TB and the supercharger inlet. That should give a pretty good indication of how much less restriction it gives, similar to the measurements I did with the intake:

[TonyB]

Andy, it has some black tape-like material around it. Do you mean a metal band, of the hose clamp variety? I took some photos of it b4 the install, but the flash was a bit too bright off the butterfly...

I hope you get a TB soon as I think many of us would like to see such a graph!

[midlife mini]

Thanks for the info Tony. Out of interest are you running a standard or modified cylinder head??

[TonyB]

Stock head, but thinkng about it down the road...

[obehave]

Too bad you can't borrow the Shark Injector from somebody. The thread on it says it runs rich. With your larger TB I'm wondering if that would have a different affect than with an OEM TB.

[Andy@Ross-Tech.com]

I certainly hope there is more holding that TB together than tape. The stock one has a metal band clamp that is cut off when it is taken apart to be modified. The correct way to go is to seal it back up with a replacement clamp, not electrical, duct, or packing tape. You may wish to peek under the tape to see if it's all that keeping a sensitive, crucial part from coming apart.