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Titanium Bolts vs stock bolts

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gt35rx

10+ Year Contributor
136
0
Jul 11, 2008
San Diego, California
I was looking into changing a few bolts on the engine to cut down on rotating mass. I.e. Engine crank bolt, cam gear bolts and the four bolts that hold my fluidampnr in place. I know a pound of rotating weight makes a great improvement on any engines performance. Anyone have any input on using titanium bolts vs the stock one's? Weight on stock bolts and titanium bolts would be appreciated if anyone else has looked into this.:thumb:
 
Thanks for posting this question twice. Dont waste your time with titanium bolts, it will cost a lot of $$ to make them while you could spend it on something else and just make more power. This type of thing is for people trying to squeeze out every last drop of performance and not for your standard dsmer.
 
Sorry for posting twice but it seems like the server was down or something. I didn't know I posted twice. Well there is a place that already has a few sizes already made. Thanks for your post tho. Anyone else have any good information?
 
I was looking into changing a few bolts on the engine to cut down on rotating mass. I.e. Engine crank bolt, cam gear bolts and the four bolts that hold my fluidampnr in place. I know a pound of rotating weight makes a great improvement on any engines performance. Anyone have any input on using titanium bolts vs the stock one's? Weight on stock bolts and titanium bolts would be appreciated if anyone else has looked into this.:thumb:

I usually just buy OE or grade 8, when you start messing with little things like that your never always gonna be able to find exact sizes and could end up having problems down the road.
 
In all honesty, Just turn up the boost.
 
I was just thinking, that if I can save a pound of rotating mass it would be worth it, don't you think? Id say, spending $100 for 7 bolts would be worth it. And doing so wouldn't be too much hard work on my end. Just switching out a few bolts.
 
Instead of repeating that its a waste how about someone answer the question?

Id like to know this as well as I'm the same way about squeezing every bit I can out of performance and don't mind paying a little extra
 
You should be more concerned with reducing the rotational moment of inertia than you are in reducing overall weight. Replacing bolts that are near the center of a spinning object don't have as much of an effect as replacing ones further from the center (see: parallel axis theorem).

You would barely notice any difference (if any at all) by replacing those bolts. It's not the same as shedding 1lb from the flywheel or a couple lbs from your wheels.

Put that $100 towards some suspension work.
 
Instead of repeating that its a waste how about someone answer the question?

Id like to know this as well as I'm the same way about squeezing every bit I can out of performance and don't mind paying a little extra

Didnt you have alot of your stuff chrome dipped?
 
Titanium isn't the cure-all. It is used for certain applications because of its ability to resist corrosion and high temperatures. It's usually alloyed with other metals. You will gain very little and spend a lot. Between the 6 or 7 flywheel bolts, the crank sprocket bolt, the 4 damper bolts, and the 2 cam bolts, you won't even shed 1 pound.
 
100$ for 1lb of rotating mass is not that good of a ratio, especially when your that close to the center of rotation. You would gain more performance by shaving down your brake rotors to minimum thickness.

clearly i don't recommend that, and you would never notice the performance difference but thats the whole point.

Obviously you guys are no fools, I am sure you know what it takes to get every little bit of performance. but the amount of mass saved on such a small rotating object would not amount to 100$ of performance in my mind. I doubt if it would even be possible to detect the any change on and engine dyno.

If your not interested in talcking your suspension yet and want to play around with getting every little ounce of performance consider having your exhaust mani ceramic coated or heat wrapped.
You can also get thermal blankets for most turbos. good gains can be made by ceramic coating IC pipes AND your Intake to prevent heat soak. also consider a cold air box or a ram air setup, there are many ways of doing that in a clean and light manner.
As far as rotating mass you could look into an aluminum one piece drive shaft or a new light weight brake setup.

Problem is none of us know your goals, so the best we can do is tell you that saving a few ounces isn't worth 100 bucks. lots of improvements that you can feel can happen for under 100$ poke around we will gladly help.
 
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Check for torque specs and how much does each bolt can tolearate. Now, I'm not telling you to do it or not. Thats your choice. Would I spend 100 bucks or so on them for the purpose of making power? No. There is better things that you can buy with 100 bucks instead of bolts. Just like everyone has mentioned. Now, if you actually do have spare money and really want to do this, then do it. Just make sure that the bolt that you are replacing, can withstand the required torque for such part. Since you have the money, you should make back to back dyno runs and see if you notice any hp/tq gains. Just don't get your hopes up.
 
Does anybody have links to places that sell titanium bolts. I would like to see how much they cost just for the hell of it. Now don't quote me on this but I read on another forum a long time ago that some Supra guy replaced every bolt on his car with titanium. He ended up saving a pretty significant amount of weight. I don't remember exact numbers because it wasn't a thread directly relating to that supra build. It makes sense considering the number of bolts we have on our cars that it might make a difference. Some people spend $800 on a carbon fiber hood to save like 40 pounds. If you could save 100 pounds by spending $800 on bolts that might be worth it to some people.
 
Well my goal for this car is high, I already have all of the mods on my car done. I'm not asking this to gain anything on a stock block as the engine is far from it. All my pipes are heat wrapped and have almost every single modification possibly done to upgrade my engine to the goal of my power level(700hp). Thanks for all the reply's. Sorry if I didn't write what I have as mods before I asked this question. I'm sure everyone assumed I was a stocker LOL. I thought I had my mod list in my profile. My next goal was to move to the hubs to remove weight. I already have a full suspension kit on the car along with bushings.
 
I don't know what it is with this forum, but people need to start answering questions insteading of repeatedly questioning the point of the OP's post.

Some of us have already turned up the boost.
We've already done the engine upgrades.
We've already bought all the CF parts.
Already have suspension upgrades.
We already have the lightest wheels on the market.
We already have upgraded engine management.
We want more.

I suggest getting to know someone in aerospace so you can have a hookup. Ti adds up VERY quickly. But I think it would be worth it. I have a bag full of bolts off some of the 2g's I've owned, and it must weigh 40 lbs. Curious as to how much all the bolts on car weigh.

However, another option is shaving your existing bolts. I've heard some of the Ford guys doing this, and reducing the weight of the car 50lbs. You just take off the excess length. Takes time, but when you are obsessive about every ounce, you can put the weights of CF supercars to shame.
 
I don't know what it is with this forum, but people need to start answering questions insteading of repeatedly questioning the point of the OP's post.

Some of us have already turned up the boost.
We've already done the engine upgrades.
We've already bought all the CF parts.
Already have suspension upgrades.
We already have the lightest wheels on the market.
We already have upgraded engine management.
We want more.

I suggest getting to know someone in aerospace so you can have a hookup. Ti adds up VERY quickly. But I think it would be worth it. I have a bag full of bolts off some of the 2g's I've owned, and it must weigh 40 lbs. Curious as to how much all the bolts on car weigh.

However, another option is shaving your existing bolts. I've heard some of the Ford guys doing this, and reducing the weight of the car 50lbs. You just take off the excess length. Takes time, but when you are obsessive about every ounce, you can put the weights of CF supercars to shame.

Thank you! If anyone has some stock bolt weights or ti bolt weights, that might be good to have right now. If not I'll have to do a lil more research on both end to come up with that info.
 
I apologize, first, that a lot of this I have written has now been said. It took me a little while to write it so here it goes:

I'm quite certain that since the crankshaft and camshaft sprocket bolts are on their respective, centroidal axes of rotation (i.e. they are not rotating about another axis) that they will make very little difference at all. I suspect that the four bolts holding the crank pulley are too little weight to matter that much, either.

Here, let's assume the bolts are made of up two cylinders: the shank/threaded portion of the bolt, and the bolt head. For the camshaft bolts and the crank pulley bolts, we will assume the bolt heads are solid and about 15mm in diameter and 7mm in height. For the crankshaft sprocket bolt, we will assume the bolt head is 25mm in height and roughly 30mm in diameter. Then, we will assume the steel and titanium used are homogeneous and their respective densities are 7.87 g/mL (7870 kg/m^3) and 4.50 g/mL (4500 kg/m^3). Finally, we will assume (conservatively) the crankshaft pulley bolts' centroidal axes are about 38mm away from the axis of rotation (crankshaft's centroidal axis).

The actual measurements of the shanks are as follows:
-Crankshaft sprocket bolt - M14x40mm
-Camshaft sprocket bolt - M12x30mm
-Crankshaft pulley bolt - M8x25mm

A little math determines the total mass of the bolts (steel; titanium):
-Crankshaft sprocket bolt: .1875kg; .1072kg
-Camshaft sprocket bolt: .0364kg; .0208kg
-Crankshaft pulley bolt: .0196kg; .0112kg

The weight savings are not fantastic, but that isn't what counts. As you said, rotating mass is what matters. The way to compare these is with the bolts' moments of inertia about the axis of rotation. Greater inertia means more force (energy/power) is required to change the object's current state of motion. So, intuitively, lower inertia means less force (energy/power) is required to change the object's current state of motion. For the crank and cam shaft sprockets, these are very simple calculations because the axis of rotation is the bolt's centroidal axis. For the crank pulley bolts, the parallel axis theorem must be used. So, the moments of inertia about the axis of rotation are as follows (steel; titanium):
-Crankshaft sprocket bolt: 1.683 x 10^-5 kg-m^2; 9.625 x 10^-6 kg-m^2
-Camshaft sprocket bolt: 7.544 x 10^-7 kg-m^2; 4.314 x 10^-7 kg-m^2
-Crankshaft pulley bolt (singular): 2.869 x 10^-5 kg-m^2; 1.641 x 10^-5 kg-m^2

As I predicted, crankshaft pulley bolts would provide the most benefit from doing this. However, noticeable gains will not be had on this scale. Compare these small numbers to what a flywheel, crankshaft, or even the crank pulley (which all have a larger mass, radius from the centroidal axis, thus a larger inertia) would produce, and you must conclude that they are insignificant. For giggles, lets look at a flywheel hypothetically.

Assume it is a uniform thin disk, homogeneous, steel as well and is roughly 280mm in diameter and 25mm thick. Ignore the holes (bolts and others). It will have a mass of about 12kg for steel or 7kg for titanium. The moments of inertia about its centroidal axis are 0.1187 kg-m^2 for steel or 0.0679 kg-m^2 for titanium. That's about 4500 times greater than the crankshaft pulley bolt, meaning the results you get for replacing those bolts would be about 4500 times less than what is gained by replacing the flywheel. In addition, the flywheel is not a uniform disk as most of the mass is towards the outer edge. Calculating for this will significantly increase the inertia, widening the inertial margin between the flywheel and the crankshaft pulley bolts and rendering any obtainable gains for the crankshaft pulley bolts as insignificant.

The advice given to you is good - your money is better spent elsewhere; the proof is in the numbers. You wanted an answer, there it is. But in the end, it is still your money and you can do with it what you please. Obviously replacing every bolt on your car with a titanium one would lighten the vehicle and gain a little more power, but that gets very expensive and most people won't pay for it.
 
I apologize, first, that a lot of this I have written has now been said. It took me a little while to write it so here it goes:

I'm quite certain that since the crankshaft and camshaft sprocket bolts are on their respective, centroidal axes of rotation (i.e. they are not rotating about another axis) that they will make very little difference at all. I suspect that the four bolts holding the crank pulley are too little weight to matter that much, either.

Here, let's assume the bolts are made of up two cylinders: the shank/threaded portion of the bolt, and the bolt head. For the camshaft bolts and the crank pulley bolts, we will assume the bolt heads are solid and about 15mm in diameter and 7mm in height. For the crankshaft sprocket bolt, we will assume the bolt head is 25mm in height and roughly 30mm in diameter. Then, we will assume the steel and titanium used are homogeneous and their respective densities are 7.87 g/mL (7870 kg/m^3) and 4.50 g/mL (4500 kg/m^3). Finally, we will assume (conservatively) the crankshaft pulley bolts' centroidal axes are about 38mm away from the axis of rotation (crankshaft's centroidal axis).

The actual measurements of the shanks are as follows:
-Crankshaft sprocket bolt - M14x40mm
-Camshaft sprocket bolt - M12x30mm
-Crankshaft pulley bolt - M8x25mm

A little math determines the total mass of the bolts (steel; titanium):
-Crankshaft sprocket bolt: .1875kg; .1072kg
-Camshaft sprocket bolt: .0364kg; .0208kg
-Crankshaft pulley bolt: .0196kg; .0112kg

The weight savings are not fantastic, but that isn't what counts. As you said, rotating mass is what matters. The way to compare these is with the bolts' moments of inertia about the axis of rotation. Greater inertia means more force (energy/power) is required to change the object's current state of motion. So, intuitively, lower inertia means less force (energy/power) is required to change the object's current state of motion. For the crank and cam shaft sprockets, these are very simple calculations because the axis of rotation is the bolt's centroidal axis. For the crank pulley bolts, the parallel axis theorem must be used. So, the moments of inertia about the axis of rotation are as follows (steel; titanium):
-Crankshaft sprocket bolt: 1.683 x 10^-5 kg-m^2; 9.625 x 10^-6 kg-m^2
-Camshaft sprocket bolt: 7.544 x 10^-7 kg-m^2; 4.314 x 10^-7 kg-m^2
-Crankshaft pulley bolt (singular): 2.869 x 10^-5 kg-m^2; 1.641 x 10^-5 kg-m^2

As I predicted, crankshaft pulley bolts would provide the most benefit from doing this. However, noticeable gains will not be had on this scale. Compare these small numbers to what a flywheel, crankshaft, or even the crank pulley (which all have a larger mass, radius from the centroidal axis, thus a larger inertia) would produce, and you must conclude that they are insignificant. For giggles, lets look at a flywheel hypothetically.

Assume it is a uniform thin disk, homogeneous, steel as well and is roughly 280mm in diameter and 25mm thick. Ignore the holes (bolts and others). It will have a mass of about 12kg for steel or 7kg for titanium. The moments of inertia about its centroidal axis are 0.1187 kg-m^2 for steel or 0.0679 kg-m^2 for titanium. That's about 4500 times greater than the crankshaft pulley bolt, meaning the results you get for replacing those bolts would be about 4500 times less than what is gained by replacing the flywheel. In addition, the flywheel is not a uniform disk as most of the mass is towards the outer edge. Calculating for this will significantly increase the inertia, widening the inertial margin between the flywheel and the crankshaft pulley bolts and rendering any obtainable gains for the crankshaft pulley bolts as insignificant.

The advice given to you is good - your money is better spent elsewhere; the proof is in the numbers. You wanted an answer, there it is. But in the end, it is still your money and you can do with it what you please. Obviously replacing every bolt on your car with a titanium one would lighten the vehicle and gain a little more power, but that gets very expensive and most people won't pay for it.

Now that's an answer LOL That makes sense to me now and I appreciate everyone's advice. I see that the gains are not that great because all the weight im trying to do is on axis's and not away from them. :applause::cool:
 
Let us not forget, that Ti has a very low modulus of elasticity, and does not yield. Basically, you cannot really torque a Ti bolt, it will just snap.

Ti is useful because of it's inertness, and its strength in high temperature environments. Using it on a car engine, is really a waste of money.
 
I just weighed a set of flywheel-to-crank bolts. A set of 6 weighs 200 grams/ .2 kg/ 7 ounces.
If you completely remove the bolts you'll save less than 1/2 pound.

Of course you can't remove them. The density of Ti is roughly 60% of steel, so if you replace steel bolts with equal size Ti bolts you'll save 40% of the weight of the steel part. For flywheel-to-crank bolts that will save 80 grams/ 2.8 ounces. Smaller bolts on other parts of the car will have even less weight savings.

see MatWeb - The Online Materials Information Resource
MatWeb - The Online Materials Information Resource
 
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Does anybody have links to places that sell titanium bolts. I would like to see how much they cost just for the hell of it. Now don't quote me on this but I read on another forum a long time ago that some Supra guy replaced every bolt on his car with titanium. He ended up saving a pretty significant amount of weight. I don't remember exact numbers because it wasn't a thread directly relating to that supra build. It makes sense considering the number of bolts we have on our cars that it might make a difference. Some people spend $800 on a carbon fiber hood to save like 40 pounds. If you could save 100 pounds by spending $800 on bolts that might be worth it to some people.

I have used the following places for titanium fasteners:
Racebolts, High Performance titanium parts at Titanium Performance
Speedway Motors - Street Rod Parts, Race Parts, Ford Flathead Parts, Sprint and Midget Racing Parts, Pedal Car Parts
TekBolt Metric Nuts Bolts Washers Fasteners

All three of these places had decent prices and a good selection. I get my titanium brake rotor fasteners from speedway motors as well.

Essentially, the weight of a steel fastener vs. a titanium fastener is approximately 1/2 the weight.

On a quick structural metal vs. weight breakdown, it would look something like this:

Heavy
--------------
Steel - (strong, 2x as heavy as titanium, 3x as heavy as aluminum, ~4x as heavy as magnesium)
Titanium - (as strong as steel but more brittle, twice as strong as aluminum, 50% lighter than steel)
Aluminum - (65% lighter than steel, 1/2 as strong as steel/titanium)
Magnesium - (75% lighter than steel, 33% lighter than aluminum, strong in cast form, high galvanic corrosion potential)
--------------
Light



As for reducing 100 pounds off a vehicle in just fasteners while retaining the same size fastener in just a different material, well, that would take quite a few fasteners. Based upon just flywheel bolts for size reference, it would take 1200 fasteners to be replaced with titanium ones. For example, a titanium bolt approximately the same dimensions as a stock flywheel bolt would be around $15.00 each. You get the picture that I am painting hopefully....

I would recommend running titanium fasteners for unsprung mass and unsprung rotating mass areas such as wheels/brakes, large driveline fasteners, suspension fasteners, etc. Don't expect it to be cheap though. Just to do my 4 brake rotor hats (32 SAE 5/16"-18 x 1" bolts) cost me ~$130.00, and using -AN aluminum washers instead of steel.

If possible, for non-structural/suspension/important parts, I would recommend using aluminum fasteners for things like bodywork, interior components, etc. It is lighter than titanium, and a heck of alot cheaper on the wallet.

You can also go with hollow fasteners as well.
 
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