TR2/3/3A Moss Supercharger for TR3A

[60TR3A]

On the one hand, Moss Motors says, "Installed on a fresh stock engine, the supercharger kit offers kick in the backside power without unduly stressing the engine, and offers superb drivability." but on the other hand it says it's only for engines with 86mm or larger pistons (I think stock is 83mm) and "high port head" (whatever that is). So, is it designed to fit a stock motor or isn't it? Anyone know?

Has anyone installed one on any model Triumph and if so, were you happy with the results? Is it really the most bang-for-the-buck one can buy and will it not "unduly stress the engine"? I'd hate to throw a rod or ruin an otherwise healthy, if anemic engine. I'm not looking to race or anything, just want a bit of that "kick in the backside" that is so lacking in my car. My engine is well tuned and has good compression so it's not lacking in "normal" power but 20+ pounds per HP is pretty anemic nowadays, you've got to admit. Even entry-level ricers have better weight-to-power ratios than that!

Your thoughts?

 

[TR3driver]

Since it includes a new intake manifold, a high port head is a definite requirement. I don't recall the exact change point offhand, but it was somewhere between TS11xxx and TS13571L, so you don't have anything to worry about on that point on your 3A.

Liner size is going to affect the amount of boost you will get, smaller liners mean more boost. But the difference between 83 & 86 shouldn't be more than the motor can handle, especially since you'll have lower compression than those of us with 87mm liners. Moss just hasn't tested that configuration, so you may need to make some small adjustments, maybe a bit more timing retard or whatnot.

The key word is "unduly"; making more power always means more stress. But as long as you don't get into detonation (knock or ping), and continue to observe the factory redline, it shouldn't be too harmful.

But last I heard, the kit didn't quite fit inside the stock TR3 engine compartment, so that may still be an issue. You might want to check with Moss on that point before ordering.

In terms of bolting-on to a healthy motor, it probably does qualify as the most bang for the buck; as any other serious increase is going to involve internal changes and hence a complete rebuild. But the result is obviously not going to be stock!

FWIW, I helped a friend of mine install a Moss blower on his 1st generation Miata. It had something like 40,000 miles when we installed it; and ISTR something like 150k when it finally died. The blower certainly contributed to it's demise, but the problem was that the crank pulley worked loose on the crank, eventually tearing up both the crank & the pulley. I understand this is a known weak spot, so perhaps it's unfair to blame the blower (but it definitely increased the strain on the pulley).

PS, forgot to mention, the Miata was never happy on pump gas, until my friend installed a boost retard module in the ignition. The retard module is illegal in CA, but it was well hidden and the smog inspectors never spotted it. If the Moss kit doesn't include some provision for ignition retard under boost, I would want to add same. It basically just extends the effect of vacuum advance into positive manifold pressure, meaning you can run more initial advance without getting detonation under boost.

 

[60TR3A]

Thanks for all the insight, TR3Driver. You've always offered sage advice in all your posts! I emailed Moss with questions based on your feedback and we'll see what kind of response I get. My mechanic estimates 8 hours @ $90/hour to do the install. Does that sound about right? Also, will the added power cause the engine to run hotter and require a better cooling fan? So far I haven't overheated even though it's been a very hot summer in SW Florida, though the temp gauge has occasionally gotten up there pretty close to boiling when idling at stop lights. Also, can I keep the old school ignition or will I need an electronic ignition to keep up with the extra carburetion?

 

[Darrell_Walker]

I installed the kit in my TR4A.

8 hours for a mechanic familiar with the car sounds about right, if you don't run into anything else.

I'm actually seeing the car run cooler, though I also but in an aluminum radiator at the same time (which may or may not actually make a difference). I did find an explanation in an old Judson manual on why that might be the case, but in any case, you aren't boosting when you are idling in traffic.

I also found the car idles (reliably) much lower and better than it ever did with the stock SUs.

I have a Mallory distributor with a Pertronix, and I don't think I have any ignition issues. I wouldn't think the stock system would have any problems, either.

 

[Guest]

If I'm gonna huff and puff it would be turbo but that's a WHOLE nuther critter. IMO, nitrous is the best bang for the buck but you gotta be careful. I wouldn't go any bigger than a 25hp shot.

That blower is expensive but according to Moss, it ends world hunger and E.D.

 

[60TR3A]

I am more & more encouraged to add the Moss S/C, based on the responses I've gotten thus far! Darrell, you didn't mention if the results met, exceeded or didn't live up to your expectations. Running cooler and having a lower idle are nice side effects but what a about the kick in the pants? Is the added oomph really noticeable and did it make the car a lot more fun to go through the gears? I'm especially interested in acceleration in first and second and in the lower speeds as I rarely take the car anyplace where I get up to highway speeds, so 0-45 MPH is where I want to feel the added power. Should I expect that and will it be very noticeable? Subtle performance gains that only show up on a stop watch won't interest me as I really do want to feel the acceleration even if it pales in comparison to today's standards. Like the guy who last restored my car 12 years ago said in an email to me today: "In the early 60's I had a 948cc Bugeye Sprite that I put a Judson supercharger on. Sure gave that little car a boost. I could then beat VW Beatles "

 

[Guest]

Seriously, think about this for a second. That kit costs what, $3500? BUy a 25 shot kit for $300-400 and drive it. Let's say you blowe it up. No big deal. Take the $3500 you would have spent on a blower and send your motor to Hap. I can't quote his prices, but I bet he can build you a nice motor for ~$5500 that you can juice w/ NO2. So worse case, for $2k more you get a stronger new engine and a 25 shot. How's that for a kick in the pants.

 

[60TR3A]

Actually, the kit is $4200 and with freight & installation it'll probably get close to or slightly over $5K, so your point is well taken.

 

[Darrell_Walker]

Darrell, you didn't mention if the results met, exceeded or didn't live up to your expectations. Running cooler and having a lower idle are nice side effects but what a about the kick in the pants? Is the added oomph really noticeable and did it make the car a lot more fun to go through the gears? I'm especially interested in acceleration in first and second and in the lower speeds as I rarely take the car anyplace where I get up to highway speeds, so 0-45 MPH is where I want to feel the added power. Should I expect that and will it be very noticeable?

The performance boost is very noticeable. You won't see a huge change 0-20, there just isn't enough time there (if you are really accelerating) to make much difference. But after that, it is really noticeable. The other thing you notice is not needed to shift down.

I'd say in exceeded my expectations, because I didn't expect the improvements at idle. It is expensive, so the question of "is it worth it" will be different for each person.

-Darrell

 

[Guest]

What about a lower final drive ratio?

 

[tinman58]

The worst thing about the Moss super charger is they are STILL OUT OF STOCK! I have been waiting since March. I called Moss a couple times and they are waiting for the H8 carbs from England. They should be ready for shipment end of July early August. I have heard similar claims about the performance. As for the cost... I.O.M. (it's only money) I have down loaded the instruction sheet(s) 25 pages. I think that it is more of a full weekend job. The apron needs to be removed and all the other parts in the front. Also the "since I am there" that will add time to the install. I am going to fab a alum raditor duct "since I am there".. I can't wait, I can't wait, I can't wait, just like a little kid.....but ther is a little kid in all of us.

 

[60TR3A]

Yikes! I just paid my mechanic a pile of money to install my chrome grill which took a lot of work (and a lot of billable hours) to fit, so now he's gonna have to undo all that work and even pull off the apron? I think his 8-hour estimate might have been a bit optimistic. Then again, I.O.M.

Fortunately, I'm in no rush for the S/C to show up because I'm shipping my car up to VT in less than 2 weeks so won't be getting it installed until November after I ship it back to FL.

BTW, if anyone is interested in a used unit, there's one for sale on Craig's List for $1600. No waiting.

 

[JKB1957]

Dan, I can't remember if your car has an aluminum radiator or not. If not when doing the SC it wouldn't be a bad time to add one, and an electric fan. Pricey, but since you're already there........
John

 

[TR3driver]

How's that for a kick in the pants.

But how long does a bottle last at full chat?

 

[Minesweeper]

Darrell, you didn't mention if the results met, exceeded or didn't live up to your expectations. Running cooler and having a lower idle are nice side effects but what a about the kick in the pants? Is the added oomph really noticeable and did it make the car a lot more fun to go through the gears? I'm especially interested in acceleration in first and second and in the lower speeds as I rarely take the car anyplace where I get up to highway speeds, so 0-45 MPH is where I want to feel the added power. Should I expect that and will it be very noticeable?

The performance boost is very noticeable. You won't see a huge change 0-20, there just isn't enough time there (if you are really accelerating) to make much difference. But after that, it is really noticeable. The other thing you notice is not needed to shift down.

I'd say in exceeded my expectations, because I didn't expect the improvements at idle. It is expensive, so the question of "is it worth it" will be different for each person.

-Darrell

I agree with all Darrell and Randall have stated. I have a less refined set-up than the Moss kit, but it is basically the same animal (a suck-through Eaton supercharger with an HD8 carb). The oomph is very noticeable and fun. You will be shocked by how quickly you get to 60 mph, so get used to the idea of getting to highway speeds more often and working up the gears more rapidly. I was also pleasantly surprised by the super smooth idle and with how responsive the car is even when not under boost. A boost retard ignition is relatively cheap insurance, at about $350 for a MSD 6BTM which also has a rev limiter (another bit of insurance).

Scott

P.s. Darrell mentioned not having to down shift as much -- that is something you will appreciate in VT. I can accelerate in overdrive up the steep hills here around the Finger Lakes of NY, whereas I previously had to down shift to 4th to maintain speed or 3rd to accelerate.

 

[tinman58]

I have the original radiator that was redone with the high effiency core, and the 10 inch puller fan. The TR runs a little warm going up hills or under extended acceleration. I am going to remove the heater today because the heater fan motor is making noise, also to clean up some wiring under the dash.

 

[swift6]

There is a big key point that 61TR3A mention that nobody seems to be addressing other than maybe Kellysguy with the lower gear ratio.

He's not planning on seeing much over 45mph with the car. If there's not much difference in 0-20 as the supercharger builds RPM and boost, then the 20-45 will come quick with probably a quick change into third after a long pull in second and then it will be right back off the gas just as boost is starting to build in third gear.

Sorry, but to me it seems like a waste of money for primarily full boost in second gear only. If your not planning on taking the car over that 45mph barrier then you might as well tune for more torque or rebuild for more torque and go to the lower ratio rear end. Then it will pull harder from a stop and you won't have to worry about lowering the top speed by such a rear end ratio change at all.

My tri-carbed TR6 would pull hard all the way to 6,000 rpm. Shifting at 5,500 rpm I could stay in third until nearly 80mph and then it would continue to pull hard in 4th gear as well. That was with the stock 3.70 rear end. If I was driving hard, 45mph would have come before I was out of second gear or right as I was about to shift into third. If I never would have the opprotunity to much exceed 45mph, I wouldn't have bothered spending the money.

 

[Guest]

How's that for a kick in the pants.

But how long does a bottle last at full chat?

Depends on size of the bottle and how many times you hit the button.

The s/c is more "correct" probably than anything else.

I'm not a "purist", but I've found over the years if you do what's right for the car, the car will do what's right for you. It's when you start thinking about just yourself is when you get into trouble.

3's aren't rockets, niether is my Midget. Anytime you try to make something opperate outside of it's design parameter you run into trouble. You take away some reliabiblty when you add power. No matter how much power it puts out, you can't drive it when it's broke. My advice is to enjoy as-is. Sure, the s/c would be o.k, but that's a lot of cake (IMO).

I'm fabrication guy, not write a check guy. I'd get a Eaton s/c off of a Riviera, Bonneville or Regal and build my own. Mazda had a s/c on a V6 too. But that's just me. Actually, I'd never s/c my car. I'd just drive the thing as it delievers that certain je ne sais quoi you can't get from anything else. These things are for motoring you and a loved one through the countryside with a picninc basket on the rack. They are to be savored, not gulped IMO.

You're looking at over 5K. I just think of what I can do w/ 5K other than add a few ponies. 5K in my world builds one heck of an engine or at least a good one. heck, it buys a whole car in the Midget world.

My level of "purity" is one of a personal relationship with the car. To take it from a neglected, abused, unapreciated hulk and transform it into a well running machine by my own hands. Is is done intentionally on a budget in an old school "hot rod" used parts kinda way. That way the car become an extension of myself. It becomes it's own being and has it's own persona. Too many new parts kill persona IMO, but I'm a third generation tech. What's right for me isn't right for you. Somethings you just gotta get new, so I'm not talking about that.

If you got the cake then pop for the ponies. Just remember, it's like any other relationship. If you neglect, abuse or beat on your spouse, they're gonna leave you one day. Your car is no different.

Just don't beat on her or you'll pay for it.

 

[TR3driver]

Lower gear ratio is a waste of time, IMO. I'm not entirely sure what's inside my current motor, but it's pretty close to stock. With the aluminum flywheel (which gives a BIG boost in 1st & 2nd gear) and the 4.10 gears, it's rather prone to spin the (205, moderately sticky) tires in 1st. And that's even with a TR6 gearbox (which has a slightly taller 1st gear than the original 3-synchro box did). With a blower, I think you'd wind up just not being able to open the throttle all the way in 1st gear.

Years ago I had a fairly hot naturally aspirated TR3A (cam, headers, compression, displacement) that could literally break the 165 tires loose in 1st gear when it came "on cam" at about 3500 rpm. I used to regularly embarrass 289 Mustangs, until I broke a tooth in the diff and had to limp home ka-thunk ka-thunk ka-thunk.

FWIW, Steve Hedke did some very careful acceleration timing with Scrappy for The Great Race. He reported that it was actually faster (with a scrupulously stock motor as required) with 3.45 gears than with the stock 3.70. I think the secret is that the taller gears mean you're putting more power into accelerating the car, rather than accelerating that tractor flywheel.

BTW, I've also got an original Judson supercharger on the shelf. Someday, probably after I retire, I'll try building a motor to put it on. Can't get much more "period correct" than that!

PS, I can't quite imagine owning a TR3 and never going over 45 mph. I hit 50 before I get out of the subdivision on the way to work!

 

[TR3driver]

But how long does a bottle last at full chat?

Depends on size of the bottle and how many times you hit the button.

Ok, 10 pound bottle, and hit the button just once.

My point is simply that nitrous is a short-term boost; while a blower will keep working as long as your nerves hold out. If you're given to high speed runs through the desert (not that I would ever do such a thing, oh no, not me!), NOS might help you get to 120 mph, but it ain't gonna keep you there.