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Hi-I'm new here and have a tire question

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Just as a data point, I was running Bridgestone Potenza 205/55-15 tires on my TR3A, mounted on 5.5" TR6 steel wheels. I was looking for better performance in two ways, both by lowering the car somewhat (but still being able to get through parking lots & my driveway without dragging bottom); and by being able to fit high-performance tires. As a budget upgrade (under $400 at the time, for wheels & tires), I feel it worked out very well.

But as always, the car functions as a system and I had to do several other upgrades to take advantage of the tires. Had ADDCO sway bars front & rear, plus Nylatron bushings in the front but still needed more roll stiffness in the front. Just bolting those tires & wheels onto an otherwise stock TR3A would not have handled nearly as well.

Not sure how well that translates to a TR4 with it's wider track and different wheel wells, but it might be helpful.
 
Building a different engine is not a horrible idea. easy to return to original if you need it. As long as he's not dropping the clutch at 4Krpm the diff, tranny and driveline should hold up okay. Massive jack rabbit starts will shorten the service life but that comes with the territory on any performance modifications.

Personally, I don't have a problem at all with what he wants to do, my resto-mod TR6 should be plenty proof of that.

Back to the tire/wheel reccomendation, 15X6-6.5 should be no problem, 15X7's could have some upper A-arm interference just like on a TR6. 16X7's should fit with no interference, again, just like a TR6. Then you can start looking at 205-215 width tires with 50-55 series profiles. Like Randall brought up though, you would likely need to address every other aspect of the suspension to take real advantage of the extra rubber.
 
Like Shawn, since I'm about as far from "stock" as you can get, I'm certainly not going to tell anyone what to do with their car and their money. And even if my car was completely original, I still wouldn't criticize the person for doing what he or she wants to do. After all, it is HIS car.
 
Brosky said:
Like Shawn, since I'm about as far from "stock" as you can get, I'm certainly not going to tell anyone what to do with their car and their money. And even if my car was completely original, I still wouldn't criticize the person for doing what he or she wants to do. After all, it is HIS car.
Click to expand...

I totally agree, bad form, especially a new member seeking assistance.

Keep us appraised of the work done and how everything turns out.
Luck.
 
Tab,

Welcome to the forum. It is not common for someone to be sharply criticized here, particularly about what they want to do with their car. You case was an anomaly and please continue to treat it as such, with your obviously good sense of humor. There is a fine line between giving advice and being critical and we all try to stay in the proper side of the line.

I'm using 16X7 Konig Rewinds, with 205/60/16 Falken tires. I love the ride and the road feel. You can see what they look like on my web site's opening page.

Good luck in whatever you choose to do.
 
Welcome to the forum, Tab. I'm using Kumho 195/65/15 on 5.5" TR6 steel wheels. I reworked the upper A Arms to get some negative camber at the front.
 
swift6 said:
Back to the tire/wheel reccomendation, 15X6-6.5 should be no problem, 15X7's could have some upper A-arm interference just like on a TR6. 16X7's should fit with no interference, again, just like a TR6. Then you can start looking at 205-215 width tires with 50-55 series profiles. Like Randall brought up though, you would likely need to address every other aspect of the suspension to take real advantage of the extra rubber.
Click to expand...

Another good tool is this tire size calculator... https://www.miata.net/garage/tirecalc.html Start with the stock tire size and you can see how close the different tire sizes are to the original for speedometer accuracy etc... You can also see how much wider the new tires are compared to the originals. If you stick with 15" wheels then you can use anywhere from 195-215mm widths (depending upon the width of the wheels)and 65-70 series profiles. See the above quote for 16" wheels.

You can use the above to choose a tire size and tread pattern that best fits your needs.
 
My dealings with PRI, purchased a set of mikunis for my TR6, put them on and could never get them right and Chris kind of reniged on his Life time of help in fact he would never return my call and he wouldnt take the carbs back and now they are in a box collecting dust and wasted 2200.00 if you deal with him I would get everything in writting and signed like a contract so if you are not happy you have a contract and legal recourse, dont pay a dime up front and hold back at least 25 percent till you are happy with the work, once he gets your money his life time of support disappears
 
I just have to jump in on this one.
200hp IS a pure RACE engine. Won't run on pump gas. Must have high compression ratio. Had better have crank fired ignition-timing is too critical.Carbs will probably need to be 48mm! Must have steel billet crank and Carrillo rods.etc, etc, etc.
If you pick up the latest copy of Classic Motorsports you will find an article about racing a tr3 (same engine as tr4). It makes 138hp at the rear wheels.Thats about 165 at the crank. It is a racing engine. Very few RACING triumphs with 4 cylinder tractor lump make 200+ hp. Very few!
A HOT street engine might make 150hp. To be a useable street engine at 150 hp you would need 89mm bore or better, otherwise it will be too peaky. If you start reving beyond 6500 rpm your nitrided,stock, prepared, crank-life, will go down hill FAST! To make 200 hp you need to rev to 8000+rpm. tranny need MAJOR upgrade to last. If you ever put race tires on it it will need the Rear Axle upgrade and you better have a LSD or a quaife diff.
Better re-set your power expectations and bring a barrel of money.
Talking with Ractorations, Darryl Uprichard stated he could build to 195hp on carbs(pure race motor), 205 on full electronic controls efi.
good luck
Rob
 
Boys;

First off, HI TAB, welcome to the forum.
Do what you want with your car, after all, it is yours!!!!!
I don't know enough about your car to give you a definitive answer for tire sizes, but I always like low and wide, just me.
Enjoy that TR4 and include pictures. Lots of pictures.

Dave :cheers:

P.S. Honda builds a little known car called the S2000 with 240 HP and very street able. It can be done, but not cheaply.
 
Thanks for all the great responses...seriously.

You guys really have forced me to rethink the situation, and I have.

I've decided not to send the car off for modifications, mainly because I have yet to drive it, or even see it in person. Only many, many photos.
I want to get a hold of all the receipts first so that I can see exactly what was done to the engine, then of course I want to actually drive it.
Besides, I don't feel comfortable sending the car off without having inspected it first. It certainly wouldn't be the first time someone dropped a head on a fender, or worse.

Depending on how it drives, I plan to keep any modifications modest, maybe only tweaking the head, a mild cam and probably some decent headers and exhaust system.

So, for the most part, I've decided to keep it like it is. I will most likely do the Panasports and wheels though. But since I will have all the original parts also, bringing back to dead stock won't be an issue.

Well, that leaves me sort of in the same situation with a small craving for acceleration, so I've decided to look for a vintage race car as well. Maybe a Triumph, maybe not. It really depends on what I can find out there. I used to own and drive an HP '59 Bugeye with a Huffaker engine putting out a whopping 100 to 105 horses, which beleive me is a great deal for a stripped down and lightened Sprite. It was a great car, lots of fun and I may go that route again.

Thanks again for the input and please note my fantasy TR4 Avatar. While it's still only a distant dream, one day I will realize that dream, and when I do...I'm going to show it off right beside my Liger cage.

Tab

P.S.

I'm working on sort of a small slide show and will post a link here if I ever get it to work.
 
14dna said:
P.S. Honda builds a little known car called the S2000 with 240 HP and very street able. It can be done, but not cheaply.
Click to expand...
True, but we're talking dual overhead cams, variable valve timing, 16 valves, 11:1 compression ratio, and a very high-revving engine. Getting a TR motor to even stay together at the S2000's peak power 8300 rpm is pretty much impossible with a 3-main crank & pushrods. And while it is "streetable", it's extreme peakiness (peak torque is only 10% below peak power) makes it less effective on the street than the rated hp would seem to indicate.

I know someone who stuck a S2000 motor into a Spitfire; and eventually decided to it back out because it wasn't competitive.

But, if you seriously want that much power from a TRactor motor, I think you'd have a better chance with forced induction. Drop the CR to mebbe 7 or 7.5 and run 15-20 psi boost with an intercooler and maybe some alcohol cooling. Just a mild cam & some exhaust improvements. Keep the rpm down, it might live ... for awhile.
 
PS,
you need to work pretty hard to get 150 street hp. To go from 150 to 200 requires an exponential increase in the amout of money required to get there-i am guessing about $20000.00. That's just the motor. Then everything else needs upgrading to match. Even at 150hp your tranny,clutch and axles should be upgraded as well as all the supension and brakes to deal with the power and speed.I have nothing to gain or lose by telling you all this.If someone tells you 200hp street hp-ask for the dyno results, build parts list, cost, details, etc. and ask for the owners contact information of such motor to verify.Both the shop and the owner will be more than proud and be willing to talk about such build. Talk is cheap. The proof is in the pudding.

Just want all the newbies to understand, these are not modern cars with 4-valve heads and it is a lot of $$$ and work to make 50% more power.The first thing you must deal with is the rods BEFORE you plan on power upgrades-they are the motors major weak link.IMHO

Tires, i like the look of 195/65-15" tires on tr4's. They don't stick out like 205's which saves your paint around the wheel wells. Still have a "period" look.
welcome aboard. I have learned much here.
R
 
Tab,
Glad you saw the light. If you want acceleration, buy an Ariel Atom. Oh, and it handles too.
The fact that it has no weather protection should be no problem in your part of the world. It will outrun the rain. Check it out at:

https://www.arielatom.com/
 
Tabcon said:
Thanks for all the great responses...seriously.
Click to expand...

You're welcome!

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]You guys really have forced me to rethink the situation, and I have.

I've decided not to send the car off for modifications, mainly because I have yet to drive it, or even see it in person. [/QUOTE]

That makes many of us breathe a *lot* easier. Personally, I couldn't ever imagine spending a gazillion dollars to radically alter a car I've never even seen, much less driven and developed a "feel" for.

Looking forward to your slide show!

Tom
 
Hi Tab;
The NO car show is March 21st I believe.
Lots of good folks, even though I belong to the Jackson, Ms club.
Hope to meet you there, and see that neat TR4.
Emmett
 
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