TailHappy

I have a RX6 with the wastegate still venting to the atmosphere. After spirited drives, the console around the shifter gets so hot you can barely touch it. On the track, it gets so hot you can smell rubber burning.

Now, the complication. Several synchros have stopped working, so I'm trying to figure out if the heat is from the bad tranny or from the open wastegate. Anyone else with this setup notice any extra heat? Is exhaust coming through the wastegate all the time (like at idle), or only on full boost? It occurred to me he extra heat may have contributed to the tranny failure, and I don't want to ruin another one!

Thanks

Wargasm

The only time anything should come out of the dump tube is when the wastegate opens under full boost pressure.

I think if you have that much heat, I'd suspect the transmission doesn't have enough fluid in it.

Brian

TailHappy

That's what I had always thought too, but I never stuck my hand under there to check... Started thinking anytime you're not giving enough throttle to "request" boost, the turbo may still be making boost, such as high rpm cruising, and it would be vented through the dumptube.

Dang, I need to check that fluid. Mechanic had the tranny off recently.....

Piranha

your wastegate isn't going to be open unless you're above a certain amount of boost, so crusing, unless you are in the triple digits, will probably not require boost, hence your wastgate won't be letting out air.

setzep

Well if he is on the track and boosting most of the time he's going to almost have a steady stream of exhaust blowing out the WG.

Piranha

Well I was responding to him saying "not enough throttle to request boost" and I doubt that is on the track over a decent amount of time.

TailHappy

Yeah, it got REALLY ridiculously hot on the track, but just noticibly hot on the street. I figured the wastegate would only be open when the car sounds obnoxiously loud, but just started wondering. Seems like that exhaust would just flow to the back of the car, but maybe there's turbulence or something causing it to get caught in the tunnel. Then again, it's probably just the transmission and totally unrelated to the dumptube....

Anyway, thanks for the replies.

Directfreak

iTrader: (2)

How about just making sure that:

1) You have enough fluid in the tranny

and

2) That you have the Wastegate exhaust pointed away and insulated from the Tranny.

apexkw

i would say the tranny and the little rubber boots that seal the cabin from the outside are bad. i doubt it is the wastegate. i ran mine open for a while and i never had a problem. i mean the way that the tube is angled it just doesnt make sense that it could blow the hot air up and make it linger long enough to make your cabin noticably hotter.

voidwasp

correct me if i'm wrong, but doesn't the wastegate open on the cool side of the turbo - venting excess gas from the compressor housing?

rynberg

You're wrong.

The point of the wastegate is to divert excess exhaust gas away from the exhaust side of the housing. Otherwise the turbo would spin too fast under high load and you would wear it out quickly.

apexkw

i think you are thinking about the bov...blow off valve

GTR

iTrader: (6)

i'm having the same problem with my t2. I don't know why its doing it but I havent' had a chance to really look at it. I changed the transmission fluid but no change. I took off my skid plate and just a little bit cooler and takes it about an hour of driving to heat up my shifter.

TailHappy

My dump tube does angle down, but I had convinced myself turbulence and a dead air area under the tranny might still be able to trap the hot air in the tunnel.

I've been lazy and haven't bothered to check the fluid. I have two synchros gone so I decided to just have the thing rebuilt. It'll be interesting to see if the rebuild gets as hot.

TailHappy

Thought I'd bring this back from the dead to add that I have sense gotten a new tranny. The old one was totally trashed....including bearings that had welded themselves. However, I'm already noticing the plastic around the tranny getting warm again. There's plenty of Redline in the tranny now, so I know that's not the culprit. The downpipe has wrapping on it, so I'm starting to be suspicious of the open wastegate again. Not to beat a dead horse, but one more time, is there anyone that does track events with an open wastegate, particularly the RX6 kit, that can confirm that it should not cause excess heat? Anyone know if Max Cooper has an open wastegate?

Like apexkw said, the wastegate angles down and I really would expect it just to blow to the back of the car. I do have very deteriorated rubber boots, so maybe that's the only problem. I just don't want to risk this new tranny. As much as these friggin things cost, I hope I NEVER have to change it again!!!

Thanks again

yallgotboost

trannys heat up its metal to metal thats why true race trans have a pump and a trans cooler like an auto

yallgotboost

trannys heat up its metal to metal thats why true race trans have a pump and a trans cooler like an auto its norm for it to get hot my daily drive chevy s10 trans gets as hot as your saying its nothing bad it just happens

apexkw

well i really dont think its the dump tube. you would have to be at high boost for a prolonged period of time so that it would be blowing hot air out. then because your car is moving and not sitting still i doubt that the heat could be staying put and making your cabin hotter. the dump tube points at such an angle that it is not even pointing at the cabin. i would replace the boots and if that doesnt slove your problem then i would ask again. i ran mine with an open dump for like a month and then the noise was unbearable...so i hope someone else will chime in that left there's open and comment. but to me it seems impossible that it would make your cabin hotter to the point that it bothers you. as far as the tranny is concerned ...it makes heat by friction. i would never touch that **** after i have been driving...it would make my hand dissapear like candy with a fat kid locked in a closet together.

yellowbird

Well, the tranny is cooled only by air, now I would assume that if a little of your 1500 degree exhaust gases are getting pulled down the tunnel that would cause you some ugly problems, you have engine bay air flowing down that way and thats not exactly cool air either. So, between the 2, I could easily see the tranny getting damn hot. Also, was there any carbon on the outside of the case? If so I would definately say that is a large contributing factor. Any carbon at all would make me concerned. Also carbon in the tunnel? Especially the strangly colored carbon you get if you are running premix. Let us know what you find.

TailHappy

Thanks for the replies. I'm pretty sure I'm just being paranoid on this one, but I just dumped nearly 3 grand on this new tranny (new tranny, plus labor of tearing down the old one to find it was destroyed). So I can't afford to be screwing these up much... The things that got me scared are that my old one worked perfectly until I tracked it. At VIR, I'm dumping through the wastegate nearly all the way around the track, for 20 minutes or so at a time. Once it started getting hot, the synchros quit working. Wasn't long before they didn't work at all, even when cool. Then having the mechanic show me bearings welded together made me believe it must have gotten a little toasty in there....

That's a great idea about looking for carbon on the case. I'll definitely do that the next time I get a chance.

bond007

Time for a gearbox temperature gauge, or apply temp strips/temp paint before the next track event, make sure it isn't running as hot as you think it is....

Regards,
--Ashraf

TailHappy

Ahh, perusing the single turbo forum I see..........that mean you're considering coming over to the dark side???

weaklink

why not have the dump tube rerouted back into the exhaust? A lot less than $3K for a rebuild (on the chance that it IS the culprit) and should give you some piece of mind.

TailHappy

Yeah, basically three things are keeping me from doing that.... 1) the whole turbo/manifold has to come off to do it properly 2) I'll lose horsepower 3) (and probably the REAL reason) I have a bad sick streak and the more I drive it the more I like the sound of the open wastegate. It's so in-your-face, and it's absolutely priceless when you get the opportunity to open it up by some unsuspecting kid with his window down that wants to race...........blood running out their ears tends to take the fight out of them before anything even starts! Oh yeah, and so far as I know I may be the first person to have the cops show up at a dyno because of noise complaints..... I know, I know, it's immature as hell but it still puts a smile on my face.....

weaklink

off topic, but are your motor mounts the ones from rotorsports racing? mine leak oil on the pass side like a summamabitch.