I thought I would post this as a public service to TT owners who have EVO silicone boost hoses and are running GT2 12 inch rear wheels (315's for tires)

Also more good to know info.....My ABS PSM lights were coming on and code was MAF fault. Mechanic said it indicated some sort of "hose leak"?

Put the car up on the lift and the inside rear driver side tire had worn through the outer most part of the silicone boost hose near where it enters the intercooler (coming from the turbo) Pretty large hole. This was the problem.

I was told it was because I had "wheels that were too wide" (and track the car heavily). So more that I learned....I thought since these were OEM wheels they would be the same however the GT2 subframe is slightly wider to accommadate the wheels (saw this in the shop manual). So another thing at least I didnt know.

But I dont think the subframe wheel combo is the total problem. Next thing I find out and what I think the problem may actually have been caused by is this........

When you compare and examine the stock boost hose to the EVO, the EVO has a larger diameter by "flaring out" and having to taper back in near the IC inlet. THIS IS WHERE IT HAD A HOLE. Also the turbo on the driver side outlet faces more out board than the right side which is why this happened on the driver side.

So bottom line if you have the above set up jack the car up and check the area between the rear tire and turbo boost hose where it enters the IC on the drivers side. You cant see this any other way.

This especially pertains to you guys that track the car as lateral tire movement may make this situation worse.

For now I have returned to the stock hose for the upcoming 4 day track event at Sebring 48h race.

Hope this may help even one person on this forum.

tom

 

Tom awesome information, should help alot of people out. On the 2nd hand that SUCKS man

I had no idea about the subframe being a bit different on the GT2, learn something new every day. I will say though, you are very lucky it didnt start any sort of fire, ND4SPD here on 6speed (Lives in NY and tracks heavily) burned through the fenderlining of his car and started a damn fire with his 18x12 bbs wheels and 335's! These things could happen and can be very dangerous!

Martin

 

Well, this is in the face of my Toyo RA-1's 335's on there way!! Bottom line is as we go closer to the edge the level frequency of detailed inspection of the car to me is now EVERY time I pull it out, cause ya never know.

This was not found by the mechanics at the dealer for my track tech inspection. I demanded they take the car back in put it up and "find out what is wrong, cause I think something is wrong" That sometimes goes a long way. In there defense it was easy to miss on a cursory tech inspection.

So to me no such thing as a "cursory tech inspection" If you are going to the track where all problems are magnified and happen faster more frequently and at the worst time, then damn it make sure that car is REALLY looked over.

Thanks Martin!

 

Hey Tom iLLM3 is correct the 8x12 bbs wheels and 335's were a problem and did cause a fire under my car from the rubbing on the rear drivers fender liner and IC hose. Even with the suspension mods and tire liner reshaping the did not help tire is to big for the TT. Unless you change out to a GT3 adjustable suspension set up. Also are you running a lot on negative camber on the rears?

 

Tom,

Sorry to hear about the problem, but thanks for such astute inspection,
observation and infor sharing!
Some combinations "work fine" until pushed to the limit and then all
hell breaks loose. Great info to know, I know the evo hoses are popular.

Marty K

How about the Samco hoses?

 

Tom, thanks for the info. I have gotten in the habit of pulling my wheel well liners for my track day checklist... pull liners, pull pads, mount pads, bleed brakes, remount liners,mount track rims, harness etc...the same routine in the same order everytime..With the wheel liners removed you can see all of the hidden areas of potential rubbing as well look behind the I/C's to make sure the upper hoses are inserted correctly as well. Your car survived with 315's a whole lot longer than mine. I cut my sidewalls on the track the first time out from the fender well slicing the outer shoulder. I have relegated my GT2 rears to drag duty only since the compression isnt as severe as road course duty... Thanks for the headsup. Kevin

 

Well Zippy (Mike) sent me detailed files to mod the wheel wells for the 335's. I think this may be ok for the street but track may be different. I think I will go with the 315 Hoosiers and call it a day.
Also going to have to stay with the OEM hose.
Marty, I will look at the Samco hoses but you know what its like at the track. The amount of flex and distortion at speed is hard to imagine when the car is just sitting in the paddock.
Thanks for the comments.

 

Kevin, good advice. I will have to add the liner check to the list. I love the GT2 wheels and 315's I am going to see if I can "make it work"!
thanks for the helpful input.

would have +1 repped ya but it wont let me!!! (again)

 

Did the tire have to wear through the fender liner to rub the hose?

 

Thanks Tom...many of us are running 315s. Wonder if the stock hoses will be equally affected even after alignment.

 

Maybe you need ta add a small spacer so you get the same postion on the wheel as a gt2 has, im using a 7mm spacers at the rear to fill the wheel arch perfectly

 

Sure, thats what they all say ... I did rep you so the pressure is on. Kevin

 

I was thinking the same thing, but the clearance is so tight the fenders have to be rolled and a decent amount of negative camber is required to fit the 335's. It would be great if the silicone boost hoses were a bit oblong shaped as opposed to round to create more clearance. With enough coaxing and tieing back, ample clearance can be created from the liner/hose. Tom, thanks for the info on the OEM hose diameter being narrower. Good point. Removing the flimsy liner bracket and tieing back the liner/hose on the drivers side will create the room for 335's. It definately should be checked reguliarily - if the tie back comes loose, a lot of rubbing would occur.

 

I have seen the same thing Tom with my 315's on the 12" GT2 wheels and as Mike said dialing in some neg camber would help for sure especially for the 335's. As you say keep an eye on it..great post BTW.

 

I have a gt2 so my fenders are factory rolled and i think my gt2 stock 18x12 sits a bit longer out, and i also have 7mm spacers, im running Yokohama 048R with the the 315/30/18 and have no problem, camber is 2 degrees