Lexus IS Forum banner

21 - 40 of 43 Posts

·
Registered
Joined
·
393 Posts
best I can explain it is at 5-6k rpms it sounds like a supercharge whine lol I dont know whats causing it.
Exhaust leak?

Replacing my driveshaft caused the exhaust to leak at the flange between the header and ypipe. I even replaced the gaskets and have tried to reinstall it a few times.

It's pretty rust and the header flange actually has a small crack so I'm not so sure what to do.
 

·
Registered
Joined
·
59 Posts
Discussion Starter #22
Tried with the car in park and revving it but that did not reproduce the supercharger whine noise so i dont think its an exhaust leak. It sounds like its coming from the rear end like under the rear seats.
 

·
Registered
Joined
·
59 Posts
Discussion Starter #24
yeah iv been reading around and could be the pinion bearings or the side bearings. I dont know if theres a way to test this or if I just need to pull it out and take it to a diff shop
 

·
Moderator
Joined
·
3,002 Posts
yeah iv been reading around and could be the pinion bearings or the side bearings. I dont know if theres a way to test this or if I just need to pull it out and take it to a diff shop
You could check for play. But as far as diff shop. I would get another diff and have the seals changed and bearing and such done in it. That way you do not have down time. If you where near. I have a few open diffs. You could use while fixing it.
 

·
Registered
Joined
·
59 Posts
Discussion Starter #27
Well for now i just replaced my diff fluid and it seems like the whine has gone down a bit so thats good haha.
 

·
Registered
Joined
·
59 Posts
Discussion Starter #29
thats the plan if it comes down to it. At the moment im taking a break from working on it. Gotta clear my mind so i can sleep lol. Always researching and thinking what it could be or how to test stuff and also have that vibration im trying to figure out as well. Putting it on pause for a few days.
 

·
Registered
Joined
·
3 Posts
Sounds like the something in the diff. Take it to a shop, put it on a lift , raise it up with someone in the car a run it in the air. Get an automotive stethoscope and u will find your noise in 5 minutes.......
 

·
Moderator
Joined
·
3,002 Posts
What are the full size dimensions of your driveshaft? I need one for my swap. you have stock w55 trans?
No, I have an auto. I cut down an aluminum crown vic shaft and added the slip and flange. Did this at my buddies driveshaft shop. I can tell you the slip number and flange number. But yours will be different on the slip.
 

·
Registered
Joined
·
67 Posts
No, I have an auto. I cut down an aluminum crown vic shaft and added the slip and flange. Did this at my buddies driveshaft shop. I can tell you the slip number and flange number. But yours will be different on the slip.
How much weight is saved removing the auto driveshaft, and should I notice less slack (play or loading) when going off from a light?
(Edit: The shaft is a 2 piece with a U-joint, so I would think I'm saving a considerable amount, going to a 1 piece. And would it be a good idea maybe to just wait? I really would like for 200mph, but I don't know if I want the 5 speed auto, to bad this car didn't have a 6 speed auto :*(
 

·
Moderator
Joined
·
3,002 Posts
2 pc or 1 pc, Has nothing to do with being able to reach "200mph" it has to do more with how much torque abuse. As far as weight, it did reduce a bit. So rotational mass is less.

Now that all being said. If you are starting a build for the Bonneville Salt flats to do the measured mile, or the Texas 2K deal than worry about 200mph. Otherwise where are you ever going to run that fast?
 

·
Registered
Joined
·
67 Posts
2 pc or 1 pc, Has nothing to do with being able to reach "200mph" it has to do more with how much torque abuse. As far as weight, it did reduce a bit. So rotational mass is less.

Now that all being said. If you are starting a build for the Bonneville Salt flats to do the measured mile, or the Texas 2K deal than worry about 200mph. Otherwise where are you ever going to run that fast?
There is many places around me where that is easily attainable. I know that the driveshaft has nothing to do with top speed. I'm wondering if there would be less play in the drivetrain. Also what do you mean by torque abuse? Is one better than the other?
 

·
Moderator
Joined
·
3,002 Posts
The output of torque from the engine is what causes a shaft to wear and break. So to speak. The more torque the more metal and bushing fatigue you get. Which the quicker you try to transfer that the more stress.

Where do you think you will hit 200? If it is a regular street. You are stupid. Sorry. I call it that because I know what it takes to go that fast, control it, and stop it. That is even knowing the area is free of surprises.
 

·
Registered
Joined
·
67 Posts
The output of torque from the engine is what causes a shaft to wear and break. So to speak. The more torque the more metal and bushing fatigue you get. Which the quicker you try to transfer that the more stress.

Where do you think you will hit 200? If it is a regular street. You are stupid. Sorry. I call it that because I know what it takes to go that fast, control it, and stop it. That is even knowing the area is free of surprises.
Would the material chosen affect how long it would last from strain? Would aluminum or steel be a better choice, than doing carbon fiber?
Also doing it on a regular street seems dumb. I would only do that on a open highway. The highway is 3 mins from my house, and then there is another branch of highway that goes off that, and its a 20mile straight that is nice and flat. Obviously its stupid to do it with people around, so it wouldn't cross my mind to even think of that, even if its just a lone semi, it still would be very rude too others.
(Edit: safety of others around me is my main priority when I do anything, I wouldn't want to get anyone else in trouble. Its crazy the amount of people that drive fast as they want as such through Atlanta. and weave all through Jacksonville area too, never seen so many ####heads running rampid on my trip back down here.)
 

·
Moderator
Joined
·
3,002 Posts
All materials wear. The toque being loaded through determine how quick each wears. Steel, aluminum, and carbon all twist so to speak. The steel and aluminum deal with it better. Carbon will shatter when stressed a lot over and over. Even if the joints are replaced often. We have done Outlaw drag cars that must have the shaft replaced every season from this stress. So take your pick. Wall thickness and diameter still have failures. In order for you to run that weight car you would need over 1000 whp. Plus need to increase real down-force more than triple.

As for your flat hwy. I assure you it is not as flat as you think. Take it from someone that has been the speed you are talking about. Sustaining speed and climbing up is much more tricky to keep the suspension loaded and tires loaded. A stray wind crossing at just 2 mph. Will push you over on a run. Without the serious down-force and the power to keep it loaded. Go buy a Bugatti then you will have most of what you need to do it on the street.

Besides, what for? Who do you think rides that fast on the street? Then do you have the skill to dive that power at that speed? What is the fastest and highest power car you have driven?

Now as for diameter you can do up to 3.25 without mods. 3.5 must have clearance mods. Wall thickness is determined by distance and transfer of torque your engine is making. How quickly you are needing to transfer this also effects wall thickness and diameter. Joint size comes also into play once you know the other variables. Now that all said. If you get say a wheel hop. Where the power is loaded then unloaded it still can twist or shatter right then.
 

·
Registered
Joined
·
67 Posts
All materials wear. The toque being loaded through determine how quick each wears. Steel, aluminum, and carbon all twist so to speak. The steel and aluminum deal with it better. Carbon will shatter when stressed a lot over and over. Even if the joints are replaced often. We have done Outlaw drag cars that must have the shaft replaced every season from this stress. So take your pick. Wall thickness and diameter still have failures. In order for you to run that weight car you would need over 1000 whp. Plus need to increase real down-force more than triple.

As for your flat hwy. I assure you it is not as flat as you think. Take it from someone that has been the speed you are talking about. Sustaining speed and climbing up is much more tricky to keep the suspension loaded and tires loaded. A stray wind crossing at just 2 mph. Will push you over on a run. Without the serious down-force and the power to keep it loaded. Go buy a Bugatti then you will have most of what you need to do it on the street.

Besides, what for? Who do you think rides that fast on the street? Then do you have the skill to dive that power at that speed? What is the fastest and highest power car you have driven?

Now as for diameter you can do up to 3.25 without mods. 3.5 must have clearance mods. Wall thickness is determined by distance and transfer of torque your engine is making. How quickly you are needing to transfer this also effects wall thickness and diameter. Joint size comes also into play once you know the other variables. Now that all said. If you get say a wheel hop. Where the power is loaded then unloaded it still can twist or shatter right then.
I can drive to what I think is acceptable to me, I'm not a professional, but I'm not a skill less maniac either. I've driven a couple BMW's and a Corvette Z06 once. I think the Corvette was the scariest one. It slid out behind me going around a inter section cause I wasn't used to the gas pedal and I let off and corrected it. I'd only had my license for like a month before this. The BMW was my friends 650i with downpipes making over 500hp, I felt alot more planted in that, and felt good after driving around for abit in it, and was more controllable than the Z06. The BMW also felt smoother, and floated on the road like butter lol. I've also driven a 325 which kinda felt like my Lexus. I've driven a Cobalt for 2weeks for work up in Michigan, and I feel as if that corners better than the Lexus, probably cause its also FWD and lighter.

I'm not really interested in drag racing. It's too short for me to actually think I'd enjoy any of it. I'd like to be free and have fun at my finger tips. I'm not really into competition, much more just the fun aspect of it.
I'd say not to jump to such power, but to get a feel for what the car can do, say 400hp turn it up and keep going, until you know the cars limits with the new power and the way it controls. and your own limits.

For aero, yeah. That is another aspect I plan on doing with my car. Not just looks but the functional pieces adds to the coolness, I want a capable car that I can abuse. That is also why a few months back I asked about the adverse effects either the L-Tuned bumper would have over the Neo V1, cause the Neo is flatter, while the L-Tuned has more curved and is rounded out surface area.

Yeah, Bugatti Veyron is the dream car.
 

·
Moderator
Joined
·
3,002 Posts
Your scare in the Vette is the weight difference. That will be multiplied going to this speed. The IS300 you are working with is close to the Vette weight. I have done more than Drag buddy. Bonneville for one. Sense the Vette was so scary, by the way. It is way more capable of doing what you want by the way.
 
21 - 40 of 43 Posts
Top