SR20's SUCK, recurring leak

[towlie]

Okay so, I've had my s13 blacktop SR for about 5 months with most of them being problem free daily driving. Recently I thought I had developed a nasty exhaust leak by scraping a hole in the down pipe when I noticed a terrible lawnmower sound.

Surprised to not find a massive gaping hole in the DP (only dented) I popped the hood and found the problem, scraping the downpipe must have blown out the turbo to manifold seal, I could feel exhaust leaking out.

I retired the car from dd duties and yanked the turbo out. The turbo to manifold gasket was so had I could wiggle the turbo with my hands and there was literally only half a gasket remaining.

Replaced/installed:

Complete OEM t25 gasket kit
S15 multi-layer manifold gasket
PBM cobra downpipe to prevent future scraping
Aftermarket turbo manifold
FRSport AN turbo line kit
CS BMC heat shield

The t25 had no shaft play and everything was cleaned/inspected before re-installation.

Stoked I hadnt broken anything removing it, everything was installed and I fired it, only to find the annoying fart sound still remains and it still leaks in the same place.

WTF?!

Could the t25 be blown even with no shaft play? Did I forget to replace anything? Maybe over/under tightened a bolt somewhere (no torque wrench everything was tightened till it could tightened no more)? I'm totally stumped, any help would be awesome!

[doomviillain]

If there's no smoke im pretty sure the turbo isn't blown. The torque specs when bolting the turbo on to the manifold is 27-35 ft-lbs I think (Someone correct me if I'm wrong). Try re-torquing the bolts or worst case, upgrade to a better gasket.

[towlie]

There was several wisps of smoke upon initial start up but I assumed it was oil that leaked out when I changed out the lines.

I'll remove it and re torque, also what gasket is considered better than oem?

[!Zar!]

Sure everything is tight?

[towlie]

Yup totally sure, I took my time to ensure everything was secure. I'm going to remove the assembly and install FRSport copper locking nuts, and re torque. Should I replace the manifold studs? I used the ones off my stock unit, perhaps they stretched? Also I can re-use the manifold gasket or replace that aswell?

Thanks all

[Sileighty_85]

.
I'll remove it and re torque, also what gasket is considered better than oem?

I love this gasket using it on 2 of my SR's and a few customers Never had an Issue

Mr Gasket Exhaust Manifold Gasket - Nissan SR20DET - Enjuku Racing Parts, LLC (http://www.enjukuracing.com/products/Mr-Gasket-Exhaust-Manifold-Gasket-%252d-Nissan-SR20DET.html)

[!Zar!]

s15 7-layer gasket is all that is needed.

Fuck all that other noise.

[doomviillain]

I would say a multi layer gasket from frsports.

edit: zar beat me to it

[SLiDe_WaYz]

Did u dent your oil pan and that noise is coming from the pickup sittin on the bottom of the pan? Happened to me just ask sleighty up there he heard it lol

[codyace]

s15 7-layer gasket is all that is needed.

Fuck all that other noise.

OEM B15, better yet, third of the cost. Heck if you need more layers you can buy 2 OEM B15 ones and be better off.

Edit: B15 SR20 are 3 layer MLS like the S15 ones (which are 6 or 7 layer)...

[codyace]

And in regard to the thread, it's not potentially leaking from the turbine housing to CHRA flange is it?

[towlie]

I've already installed a new oem multi layer manifold gasket.

Did u dent your oil pan and that noise is coming from the pickup sittin on the bottom of the pan? Happened to me just ask sleighty up there he heard it lol

Nope, looks straight.

And in regard to the thread, it's not potentially leaking from the turbine housing to CHRA flange is it?

Im fairly certain it isn't, if I put my hand between the turbo and car I can feel exhaust being pushed out of where the manifold to exhaust gasket is..

I'm thinking I didn't tighten something enough. Heres my plan:

Remove assembly, remove studs (on exhaust manifold) tighten with loc-tite. Install with copper lock nuts and I'll look around for another gasket option (mani to turbo) ...but first I need to find motivation lol :|

Thoughts?

[codyace]

The turbo to manifold gasket can be purhcased at your local Nissan dealer, same gasket as used on the TT-Z cars. You can also get new OEM hardware and locplate when you order that gasket too to ensure a good seal. Those copper lock nuts work too, but I like new OEM hardware with those plates.

Loctite isn't going to do much in that area, it's way beyond the heat range to work.

[e1_griego]

You sure that turbo manifold isn't cracked or something? Since it's an ebay tubular t2.

Try your stock manifold...

[benarovi]

you NEED the locking tabs for the mani to turbo, get the copper bolts, use loctite on all the bolts, tighten as hard as possible, bend the tab correctly, and put back on the car see how it does. get s.s turbo lines if you dont already, makes taking all that off much easier
use the oem gasket on fr sport for the turbo-mani

[anarchyperf]

As benarovi said, make sure you put the locking tabs on or you will become very familiar with tightening the nuts and replacing the studs.

[towlie]

The turbo to manifold gasket can be purhcased at your local Nissan dealer, same gasket as used on the TT-Z cars. You can also get new OEM hardware and locplate when you order that gasket too to ensure a good seal. Those copper lock nuts work too, but I like new OEM hardware with those plates.

Loctite isn't going to do much in that area, it's way beyond the heat range to work.

That's what I figured about the loctite, but I don't think it will hurt lol. Found an oem multi layer flange gasket at FRSport I'll add aswell.

Is there a specific way to bend the locking tabs? I used a flat head and rubber hammer, it sure didn't look pretty lol

You sure that turbo manifold isn't cracked or something? Since it's an ebay tubular t2.

Try your stock manifold...

I got it from huffandpuff00, it looks legit to me. But I'll put the stock back on :(

you NEED the locking tabs for the mani to turbo, get the copper bolts, use loctite on all the bolts, tighten as hard as possible, bend the tab correctly, and put back on the car see how it does. get s.s turbo lines if you dont already, makes taking all that off much easier
use the oem gasket on fr sport for the turbo-mani

Got it.

[Sileighty_85]

wait so, your using the S15 gasket on an AM manifold?

is the Port flange a one piece design?

If so thats your problem. You cant use a S15 MLG with a one piece flange cuz of the rivets used to hold the MLG together are keeping the flange from sealing properly

[codyace]

Is there a specific way to bend the locking tabs? I used a flat head and rubber hammer, it sure didn't look pretty lol

Yea it's not going to look pretty at all, I used a screw driver and a hammer much like you..the key is to get a good solid crease in the tab to keep in place.

I've had the OEM 300zx Turbo hardware on all of the stuff I've done, and NEVER had a leak there....figure that stuff is designed from the OE to last for quite some time.

I'm not a big believer in those copper nuts either, just because of the fact that the OE stuff works so well. Not saying they dont work, I just don't like spending money on aftermarket stuff when OEM Nissan works so well.



I got it from huffandpuff00, it looks legit to me. But I'll put the stock back on :(



Got it.[/QUOTE]

[arg23]

I kept burning out gaskets, and having the turbo come loose from the manifold during our races, losing all boost as hot exhaust gases exited pre-turbo. A little further investigation found a great deal of scale buildup, or rough surface from the gasket material "bonding" with the turbo flange.

I think under high stress and heat, the gasket changed properties and created an ultra hard carbon deposit on the flange. I kept putting fresh gaskets in but the surface was not flat and the new gasket would soon fail in exactly the same manner.

Inspect your gasket mating surfaces for uneven finish, I surfaced ours and the problem has been resolved since. Additionally get new studs, they stretch out over time and loose some of their tensile strength, they wont stretch and hold during heat cycles. And maybe dont use cheap gaskets sent with the cheap kits, I really like the OEM style, they seem a lot more durable.

We dont bother with the locking tabs on the race cars, we tried to be very diligent with them when we went through a half dozen gaskets, they didnt help. I use them on my street cars however.

And I have always kinda liked Cody's stance, stock cast manifold is pretty badass. We arent using it anymore on our race car, but it doesnt see the same kind of stress the street cars do. If I had a badass extrude honed, and external wastegate stocky like Cody though... I would be rockin that.

[towlie]

I ALWAYS use OEM gaskets, no matter the application. Also as previously mentioned im going to return to stock manifold

Just purchased several items from FRSport including this:

Nissan 4 Bolt Turbo Turbine Inlet Gasket T25 T28 SR20DET 4 Layer Type (http://www.frsport.com/Nissan-4-Bolt-Turbo-Turbine-Inlet-Gasket-T25-T28-SR20DET-4-Layer-Type_p_18585.html)

I'll update accordingly, thanks for the advice

-Zach

[!Zar!]

Fuck lock tabs.

I purchased a stamped stainless steel gasket from ATP turbo, tightened the fuck out of the nuts, and welded the nuts down. Never have had any sort of leaks since.

http://www.atpturbo.com/mm5/graphics/00000001/Catalog%20Images/Gasket/GSK-T25Inlet-225225.jpg

[mikerbike]

Oh dang. I should get rid of my SR before it develops a leak. I didn't know this was such a common and terrible problem.

I don't run a turbo-manifold gasket on my KA. It's only been that way for about a month of daily driving.

My SR has (what I assume is) the original gasket with a factory manifold. I've reinstalled it twice. If I need to remove the turbo again any time soon, I'm leaving the gasket off.

[anthonyr sil8ty]

Oh dang. I should get rid of my SR before it develops a leak. I didn't know this was such a common and terrible problem.

I don't run a turbo-manifold gasket on my KA. It's only been that way for about a month of daily driving.

My SR has (what I assume is) the original gasket with a factory manifold. I've reinstalled it twice. If I need to remove the turbo again any time soon, I'm leaving the gasket off.

do you realize how dumb you sound?

anywho OP, I had the same issue when I was bottom mount, I was running a aftermarket downpipe, test pipe, and cat-back. I didnt have the flex jont anywhere in the system so all the vibrations etc put all the strain on the oem nuts and studs. I doubled nut'd and used lock tite on the studs which seemed to work the best.

[!Zar!]

A lot of diesel truck guys, as well as dsm guys run their turbo without a gasket.

Just make sure both flanges are straight, and smear a little wheel bearing grease on the flanges and tighten it down.

But if you do the way I suggested, you won't have to worry about exhaust leaks.

WELD THE NUTS.
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash2/179651_10150126873115867_592705866_8278528_650643_ n.jpg

[anthonyr sil8ty]

A lot of diesel truck guys, as well as dsm guys run their turbo without a gasket.

Just make sure both flanges are straight, and smear a little wheel bearing grease on the flanges and tighten it down.

But if you do the way I suggested, you won't have to worry about exhaust leaks.

WELD THE NUTS.

dsm guys dont use studs and nuts like nissan's, they have bolts that run throught the manfiold and into the exhaust housing. i would imagine the dsm turbo flange bolts being alot stronger then 8mm studs. SPOT WELD THE NUTS i will agree with.

[codyace]

A lot of diesel truck guys, as well as dsm guys run their turbo without a gasket.

Just make sure both flanges are straight, and smear a little wheel bearing grease on the flanges and tighten it down.

FWIW: Real Diesel guys (not those bro dozers) run OEM gaskets ;)


Well, even I can't deny the fact that doing this will work...I guess in the grand scheme of things I can say if you're pulling the turbo you're taking the manifold off anyway, so it's not like it's anymore work for removal LOL.

....although I think I'd use Copper RTV before grease, but I guess the end result is the same, burnt crud to help seal it up haha.

Fuck lock tabs.

They're still the second best option. Consider them the condoms of the world, with welding being abstinence.

[fliprayzin240sx]

You sure the flanges are not warped? Also, like already stated, since its an aftermaket manifold and you fucked the DP up from bottoming out...are you sure the manifold isnt cracked to hell? I'm willing to bet the manifold is cracked on the collector before anything else...

[e1_griego]

^Yup, exactly.

[mikerbike]

do you realize how dumb you sound?

Internet sarcasm getting the best of you again?

But really, SR20s SUCK because the some exhaust gasket goes bad all the time on every SR20 ever made. Put your SR20 in the garbage.

[towlie]

You sure the flanges are not warped? Also, like already stated, since its an aftermaket manifold and you fucked the DP up from bottoming out...are you sure the manifold isnt cracked to hell? I'm willing to bet the manifold is cracked on the collector before anything else...


when my leak first started I had the stock manifold, i didnt install the aftermarket until i was replacing everything. i bought it secondhand perhaps it was fucked up idk, scrap metal now anyways so it doesnt really matter lol.

Im not running a diesel or mitsubushi turbo so using grease or rtv in place of a gasket sounds sketch, also i really dont want to spot weld any bolts.. but thanks for the suggestions

[Broadfield]

I never ran any sort of gasket on my Full Race GT3071R setup... obviously no leaks. I wouldn't attempt this on some of the thin wimpy flanged manifolds out there though. As stated by others, you would need to make sure the flanges are true on both the manifold and exhaust housing. You could always glue some sandpaper down to a board then run both mating surfaces across it to make sure they are good to go. Any weird spots will show up instantly after a few passes. You can then address the issue(s) accordingly.

[SLiDe_WaYz]

Buy the mr gasket copper one from enjuku I have it. Seems to do the trick for me. Haven't blown a gasket yet.


Then again I've only been driving it daily for about 2 weeks in the past year it's been on there

[towlie]

ill inspect the stock manifold for any sort of imperfections, and the turbo.

Was the gt30 top mount? does that make a difference in using a gasket or not?

[Kingtal0n]

The only thing I disagree with is the welded nuts theory. Are you poor fellows off your welded nut brains?
What happens when you need to take the turbocharger off- You packin' a grinder and some new studs and nuts in the trunk? Its not like a tattoo!

[Broadfield]

If it's just a tack weld then you can still break the nut loose without any repercussions.

[towlie]

tacks arent hard to break dude. thats just a little to, er, extreme for my tastes lol. plus i dont feel like going to the hassle of trying to find a decent welder locally

[!Zar!]

Exactly.

Lock tabs, safety wire, even regular lock nuts all require the manifold to be removed in order to remove the turbo.

I tried all sorts of bullshit, and in the end the stainless steel gasket and tack welding it has left me trouble freeeeeeeeeeeeeee.

[Sileighty_85]

wait so, your using the S15 gasket on an AM manifold?

is the Port flange a one piece design?

If so thats your problem. You cant use a S15 MLG with a one piece flange cuz of the rivets used to hold the MLG together are keeping the flange from sealing properly

Never got a response on this so just wanna throw this back up

[Luvs2slide]

I never had an issue using the s15 layered gasket and oem locking tabs. I just tighten the 4 bolts real good. Drifted hard with this on OEM mani and aftermarket SS ones.

Can you take some pics of the way it sits now? Is there any visible warpage you can see? Can you still feel the exhaust gases leaking?

[fliprayzin240sx]

Well either way, you're gonna have to pull the whole manifold/turbo off. When you take it off, you should see the soot on where its leaking. Depending on where it is will dictate your next course of action. If its leaking between flanges, I'm willing to bet one of the flange is warped. If its not, then its coming from a crack on the manifold.

[towlie]

Never got a response on this so just wanna throw this back up

Sorry dude, yeah pretty sure its a one piece design and yes I am using the s15 mlg. Defiantly a possibility, interesting idea. Happened to you?

I never had an issue using the s15 layered gasket and oem locking tabs. I just tighten the 4 bolts real good. Drifted hard with this on OEM mani and aftermarket SS ones.

Can you take some pics of the way it sits now? Is there any visible warpage you can see? Can you still feel the exhaust gases leaking?

Yeah ican get pics of everything tomorrow night after work i really don't feel like touching my car right now LOL. Parked it in the shop that's as far as I'm going :| edit: and no I haven't tried to see if its still leaking in the same spot, turned it on to re park it and I could hear it clearly so I assume yes same place.

Well either way, you're gonna have to pull the whole manifold/turbo off. When you take it off, you should see the soot on where its leaking. Depending on where it is will dictate your next course of action. If its leaking between flanges, I'm willing to bet one of the flange is warped. If its not, then its coming from a crack on the manifold.

I'm really dreading taking it off again, its a pretty big pita! I'll keep my eyes peeled for any signs and post pics to. It's only ran for 5-7 minutes total since everything has been installed,would it show soot or other signs of leakage already?

[Sileighty_85]

Sorry dude, yeah pretty sure its a one piece design and yes I am using the s15 mlg. Defiantly a possibility, interesting idea. Happened to you?

Its cool,
Nah seen it happen a few times

[R33E8]

You can always try making your own gasket using flexible graphite sheet/graphoil.. It's really compressible and could easily conform to any minor defects in the mating surfaces.. Mcmaster carr has some, I think it's less than $20 for a 12x12 sheet that is 1/16" thick(which is what I use)..

[di-devol]

Problem solved.
http://img576.imageshack.us/img576/3502/1001039su.jpg

[Sileighty_85]

That's nuts, Im surprised how many ppl have issues with that gasket.
I have an unknown AM manifold, Oem gasket with stock locking hardware daily and drifted the car for 5 years now and never had that that gasket blow, even bashing my exhaust and down pipe on all the shitty roads over here

[sharpe_corners]

Exactly.

Lock tabs, safety wire, even regular lock nuts all require the manifold to be removed in order to remove the turbo.

I tried all sorts of bullshit, and in the end the stainless steel gasket and tack welding it has left me trouble freeeeeeeeeeeeeee.

+1917327376376373647637364737336746365736547354774 637436463+7436436:werd:

[arg23]

[QUOTE=di-devol;4429564]Problem solved.
QUOTE]

Love this. If surfacing hadnt resolved our issues back in 2009 we were going to do exatcly this. Came up on another project recently as well, wasnt certain I could weld inconel though...

[towlie]

Lol, that's yours Tim? I dunno ive been considering tacking it. I really DONT wanna have to do this a third time -_-

[di-devol]

Naw, it's something Alex showed me when I was having the same problems. I used one of those really thing steel gaskets that failed alot. Getting the multi-layered one and locking tabs fixed it for me.

Hope you fix it man.

[huffandpuff00]

hey zach,
Sorry to hear you are having a leaking problem. I never had a problem with it leaking... this is the same gasket I was using with it installed on my car and Im reusing it on my car now. I think its the normal 2 layer. http://i2.frsimg.com/images/detailed_images/FR_0212930679874d12a6d3b8144.jpg

[towlie]

Naw, it's something Alex showed me when I was having the same problems. I used one of those really thing steel gaskets that failed alot. Getting the multi-layered one and locking tabs fixed it for me.

Hope you fix it man.

thats my plan of attack, it should fix it. I hope :ugh:

hey zach,
Sorry to hear you are having a leaking problem. I never had a problem with it leaking... this is the same gasket I was using with it installed on my car and Im reusing it on my car now. I think its the normal 2 layer. http://i2.frsimg.com/images/detailed_images/FR_0212930679874d12a6d3b8144.jpg

No worries, tomorrows my day off im tackling it then. picked up this gasket:

http://i2.frsimg.com/images/detailed_images/FR_0112930681304d12a762632c8.jpg

Looks legit

[huffandpuff00]

so you are going to tack the bolts?
Im ordering my exhaust tomorrow, so ill hit you up when it shows up next week

[towlie]

Nah, Alex suggested I use FRSports copper lock nut. Above post was a typo my bad i was at work. If that fails I doubt I'm going to touch it for another year LOL. And word just shoot me a text

[towlie]

update, sorry for taking so long stupid life has been keeping me busy lol

heres the SUCKY sr

http://i165.photobucket.com/albums/u51/qwerty_7878/AMENIGA001.jpg

Manifold in question'

http://i165.photobucket.com/albums/u51/qwerty_7878/AMENIGA003.jpg

lol

http://i165.photobucket.com/albums/u51/qwerty_7878/AMENIGA002.jpg

Found the problem.

http://i165.photobucket.com/albums/u51/qwerty_7878/AMENIGA005.jpg

http://i165.photobucket.com/albums/u51/qwerty_7878/AMENIGA004.jpg

into the scrap metal bin!

http://i165.photobucket.com/albums/u51/qwerty_7878/AMENIGA006.jpg

anyways, i think the only aftermarket manifold im ever going to run is Full-Race. my SR runs fine now, few kinks here and there i need to find time to straighten out but i fixed this, no more leaks! got me to work yesterday. thanks duders fot your help

[!Zar!]

Wow, that thing is super shitty.

Stock SR manifold that is honed and extruded, then ceramic coat it > your butt cheeks.

[SLiDe_WaYz]

Wow, that thing is super shitty.

Stock SR manifold that is honed and extruded, then ceramic coat it > your butt cheeks.

This, waiting to get mine back, it cost 170$ total. That was buying a old stock manifold shipping it off to get it honed ext, and getting it ceramic coated.

[codyace]

For the record, Stock Manifold time and time again is the best T2 manifold available :D Leave the tubular junk for the hood poppin hardparkers :D

Wow, that thing is super shitty.

Stock SR manifold that is honed and extruded, coated, and modded for external gate > your butt cheeks.

Corrected for level 10 awesomeness :D

[towlie]

yeah, i definatly learned my lesson lol. i dont think ill be doing any fancy flow work with the manifold anytime soon, i never want to take it off again!!

also,

http://a1.sphotos.ak.fbcdn.net/hphotos-ak-snc6/262277_617871723376_42501326_33663668_6484455_n.jp g

http://a4.sphotos.ak.fbcdn.net/hphotos-ak-snc6/254220_617872017786_42501326_33663670_5869476_n.jp g

[codyace]

External gate FTMFW

[cotbu]

So you swapped engines and chassis 's because of a leaky gasket?;)

[anarchyperf]

What aftermarket manifold were you running?

[Kingtal0n]

whats hardpark?

[di-devol]

Awesome, glad you fixed it.

[towlie]

Idk the brand i got it in a trade. Probably eBay /:

And thanks man!^^

[Wake]

Glad you worked it out lil buddy.

I really like codys external wg idea. but I love tomei too much.

[K_style]

Found the problem.

http://i165.photobucket.com/albums/u51/qwerty_7878/AMENIGA005.jpg

http://i165.photobucket.com/albums/u51/qwerty_7878/AMENIGA004.jpg



Fuck that ebay shit....
Dont you work at Verizon in Cornelious ??

[omgRWDgoodness!]

This, waiting to get mine back, it cost 170$ total. That was buying a old stock manifold shipping it off to get it honed ext, and getting it ceramic coated.
Mind sharing where you're getting it done that cheap? GetHoned wants over $600 for a 6-cylinder exhaust manifold! :tweak:

[codyace]

Mind sharing where you're getting it done that cheap? GetHoned wants over $600 for a 6-cylinder exhaust manifold! :tweak:

As much as I like Extrude Hone, even i'll admit to their pricing getting rediculous since they started. Any other options would be great knoweldge to have :D

[towlie]

Fuck that ebay shit....
Dont you work at Verizon in Cornelious ??

Word!
And no I work at America's tire in Tualatin lol

[codyace]

Glad you worked it out lil buddy.

I really like codys external wg idea. but I love tomei too much.

I'll convert you. Sell that fancy thing to some aspiring drift kid, and join the bandwagon! :D :ddog:

[!Zar!]

I would go external on my setup, but the added bling would increase the chances of getting sent to the state ref; on the rare chance I drive my car around.

[codyace]

I would go external on my setup, but the added bling would increase the chances of getting sent to the state ref; on the rare chance I drive my car around.

That freakin blows :/

[!Zar!]

It's cool.

Boost creep gives me a sweet adrenaline rush.

Maybe I'll port the flapper out and toss the tomei gate on it.

[codyace]

It's cool.

Boost creep gives me a sweet adrenaline rush.

Maybe I'll port the flapper out and toss the tomei gate on it.

Let me know how that one works, I gave up trying after the Garrett, the HKS, the other Garrett, and the Forge all blew on me. Yay.

Boost creep is kinda cool, keeps ya in check though for sure. Amazing how so many idiots stay in it, thinking there car is running 'better' when it's really on the verge of kicking a rod haha.

[K_style]

Word!
And no I work at America's tire in Tualatin lol

No shit !????

I used to go to Tualatin location to get the tires... haha I must have seen you..

[towlie]

I've only been there a few months. Come in sometime and see what's up lol

[K_style]

NVMD... ..

Double post

[K_style]

I've only been there a few months. Come in sometime and see what's up lol


Are you sales ? or installer ?

I am ganna need a set of tires pretty soon... Wonder if you could get me better pricing for me than Normal Intel discount

[towlie]

Are you sales ? or installer ?

I am ganna need a set of tires pretty soon... Wonder if you could get me better pricing for me than Normal Intel discount

Not quite in sales yet, but i could probably still get you deals ;)

PM me with sizes. any brands youre looking for specifically? how much is your discount?

[K_style]

Not quite in sales yet, but i could probably still get you deals ;)

PM me with sizes. any brands youre looking for specifically? how much is your discount?

Intel employee discount you guys have it $50 off on order $250 or more.

or $100 off on $500 order or more

[towlie]

thats actually a pretty good disvount. it really depends on the tire brand/size..