I made a thread about this in the 3rd and 2nd gen forums over a year ago, and now I want to ask it here in the single turbo forum. Somebody posted this article by BDC Motorsports http://forum.teamfc3s.org/showthread.php?t=50764

For purposes of this thread, let's say that your car didn't overheat (as in water temps climbed and blew a coolant seal). Definately mention if you had heatsoak-induced detonation though. Also let's assume your methanol system functioned correctly. Now, answer these questions:

1. What turbo and boost level? Estimated whp?

2. What exactly blew? Blown seal, cracked iron, etc

3. What octane fuel were you running, or what % meth?

4. If you know what AFR or what timing you were running, post that. Also post knock count at the time if you know.

5. Post any other important information such as you were drag racing, running it on a race track, really cold outside, etc.

 

1. Borg Warner S475, 27ish, Mid 500s???

2. Apex seals broke.

3. C16

4. Don't know, to damn scared to look at the A/F gauge and couldn't datalog because apparently the laptop was scared too.

5. Drag racing.

 

-T78, halfbridge motor, 490rwp, tuned by steve kan at 20psi
-Have not broken down engine yet to determine
-I was using 93 pump with 92% denatured alcohol. It was not really cold out for it to really overboost. I have seen it spike to 24psi, but AFR's stayed decent. I didnt pay attention to the boost because i was racing.
-I was street racing, started in 2nd gear, was in 4th gear at about 6300rpm when it went pow.

 

4 year old motor, streetport, t51kai turbo, 27 psi, c16 gas, 603 whp

never broke, always abused

tunes by Kan

 

1. Turbonetics 60-1 small-shaft T4 w/ P-Trim 0.96 A/R undivided turbine, approximately 10 years old, ~25psi of boost, 440rwhp and approxmately 360-370ft/lbs of torque as graphed from the dyno

2. Front iron housing cracked at the upper dowel land; lateral crack causing a subtely blown out land and high pressure oil leak

3. Approximately 65-70% 93 octane pump fuel and 30-35% methyl alcohol at that boost and RPM (65/35 - 70/30 ratio)

4. AFR's dipped below 10:1 while I wasn't watching the wideband. My fault in my over-confidence in the tune of the car. Was running 16*BTDC with a 7* split. Have no idea on knock count but the engine definitely knocked. Felt it for a split second stutter. My theory is I induced knock by flooding the engine and blowing spark out which, in layman's terms, shook the hell out of the thing. Upon disassembly, no real signs of garden-variety detonation due to heat or pre-ignition; rotors and housings were carbon free. 5 of 6 corner seal springs on the front rotor were flattened. No other damage to rotor or seals.

5. Sitting on the dyno. Was in late December '06. Car was running beautifully for the past 5 months w/o any hitch.

B

 

^ I'm surprised you were running timing that aggressive for that high of boost even with AI. I have a T04S with I similar specs and I plan to run it to 20psi on straight 110 octane (just saving my money for a good EBC and dual EGT to do it right). I was thinking of starting with an advance of 10 in the peak torque area gradually increasing to 14 by 7500-8000, with around 12-13 split. Then maybe advance the timing and reduce split based on EGT's, knock, and dyno numbers.

Was this on an REW blocK?

 

S4 13BT block w/ 8.5:1 rotors. Old style irons.

The next time I go to do some real load tuning on it, I plan to run less advance but stay with the same split. I kept the advance curve flat from 15psi up to 30. Seemed to work alright.

B

 

anyone else?

 

1st time out on race gas.

1. TA45 turbo, 27 psi, 480rwhp.

2. Cracked the front iron around the oil feed.

3. Sunoco supreme nos race gas.

4. 11.5 a/f, no idea on timing or knock.

5. Drag racing.

With 26 x 8.5 inch slicks and a big turbo on the 12a I had to rev it to 11500 rpm to get it off the line without bogging down. Im sure this contributed to the iron cracking.

2nd time at the track on race gas.

1. TA45 turbo (back cut turbine wheel this time), 25 psi, 497rwhp.

2. Broke all rear apex seals.

3. Sunoco supreme nos race gas.

4. 11.5 a/f, no idea on timing or knock.

5. Drag racing.

Had ebc problems on the day with the car overboosting and sitting on the boost cut for 5 or 6 passes until I figured out the problem. Turned out to be having the sensitivity setting of the eboost too high. Motor was already damaged before I got it right (had no vaccum at idle), so I knew I had to pull it apart anyway and just kept racing. Got another 10 full power passes before the motor went bang.

 

sorry.. I dont like even readying this stuff..

13rew stock as you can get. 430rwhp

gt40r turbo 21psi (but spiked up bad)

110 leaded

Clutch let go at the top of second gear causing all sorts of issues. I thought it was spinning and slammed 3rd only to over rev- and had bad boost spike on logs.. Motor was old 60k + so it was time.

Had damage to front rotor, housing, chipped seal.

Knock ??

 

t04e 57 trim. running 22psi. 436whp 356wtq

cracked rear housing.

straight California 91

chipped s5 ecu, thats would only retard timing to 14psi then after that...

freeway pulls with a couple R1's. they were surprised!

 

this thread is making feel queasy.

 

Good stuff. Keep 'em coming.

 

anybody else blown a motor recently?

 

Nah it's making me thankful I'm paying the extra $ to add some dowl pins along with some seals that usully don't break when detonated These threads are good only because we get to see hear first hand where the weak spots are on our egines.

 

Allow me to contribute my experience to my own, well, prophetic thread.

I had been running straight 100 unleaded ever since I installed a T04S on my 88 T2. Long story short, it ran great at 18psi but when I cranked it up to 21, the only air hose I hadn't secured well (big OMP spider line to the back of the UIM) blew off. The ECU didn't see all the boost (datalogs show only 10psi) and the car leaned out and severely detonated. Later I found out that the insulator broke on two of my plugs. The car still ran but it idled low and didn't pull more than 11 inches of vacuum.

I didn't even compression test the motor, I just pulled it the next week. Upon tearing the motor down I discovered that my RA Super Seals were... intact! I had never compression tested the motor. I guess I always figured it was going to blow up, and I was just waiting for it. I spec'd out every seal, and they were like 1.97mm wide and 7.96 mm tall or whatever... almost brand new, every single one of them, no signs of damage. They were only 4000 miles on them anyway. Keep in mind that this motor was SEVERELY detonated multiple times. In this case, my AFR hit 15:1 at 21psi boost, not to mention my timing as advanced 11 degrees too far because an improper boost reading puts the PFC in a different part of both the fuel and timing maps. That wasn't even the first time I had detonated it by any means... I had serious boost creep problems when I was on stock turbo.

At this point though, the motor, on first inspection, appeared in pretty good shape. I felt like a pretty big dumbass for not compression testing it and changing the plugs to see if it would run like new again. But then I examined the housings and saw that my middle iron had a chip in the coolant passageway area and could have blown a coolant seal at any time (I had overheated it due to a busted clutch fan a while back). And my front rotor housing had edge wear and chatter that was out of spec. So I guess its days were numbered either way. Right now I'm gathering parts to put the motor back together with low mileage s5 irons and rotor housings.

 

That's what I like to hear. I've heard lots of good things about the "super seals" and will be replacing the stock seals for these when the motor is apart. Short of buying expensive ceramic apex seals I think these black seals are a good alternative.

 

Contact SpeedNYC for info on the super seals... he steered me away from them

 

We use the super seals and have no problem with it.

 

If Kilo recommends them I'll take that as proof positive that the black seals work.

 

"line to the back of the UIM) blew off. The ECU didn't see all the boost (datalogs show only 10psi) and the car leaned out and severely detonated. "

i had something similar yesterday on the dyno... on the 18th of 23 runs my PFC showed a loss of boost from the peak 21.6 PSI at 6576 rpm to 12.7 PSI at 7836 where we got out of the throttle.

the dyno showed around 21 PSI with no boost degradation which was correct. of course the PFC was giving out instructions for a much lower P cell.

i replaced the hose from the UIM to the MAP and fixed the problem...

AFR was around 13.

the run made 498 SAE hp. pre turbo EGT was 1640 and knock was 21.

probably thanks to 1400 CC/Min of Methanol. (the base fuel is 93 octane pump)

after 3 years on the motor and over 100 2000-8000 dyno pulls it idles at over 17 inches.

howard

 

Awesome.

B

 

I had the HFS-5 running 100% water at about 17% of fuel.

I was driving home from the autoparts store, I was running on just the wastegate spring (6psi) with the boost controller turned off, as my setup was only partially tuned (up to about 6-10psi). I pulled out with a little room to spare but needed to accelerate quickly, I went full throttle for a moment in 2nd gear and lost all compression as my boost gauge spiked. When I got the car home I had discovered a wastegate line failure.

Water injection was working perfectly.

1. TO4e dont have an estimated power, made about 320whp at 8psi

2. Cracked two corner seals on one rotor and one corner seal on the other. One rotor was destroyed, the other rotor was ok. Both housings were gone, and both irons were gone. Turbo turbine wheel was gone as well.

3. 91 octane and 17% water

4. AFR was really rich, in the low 11 high 10 range. Timing was very conservative, don't know exact numbers off the top of my head.

5. It was probably 80 degrees outside, just pulling into traffic. Boost gauge showed a boost spike to about 27psi. My system was built to spool quickly, it made this pressure by 5000 or so rpm. Unfortunately I didnt' have a log of the event. I was quite crushed as I put a countless amount of time and effort into putting this car together correctly, with the right parts and the right systems. I was very excited about the water/methanol possibilities. Yet I still couldn't get the car through emissions...and that was a big time frustration.

Car now has an LS1... I am very happy with it...