Progress Thread Flghtmstr1's 700 Rwhp Build

Discussion in '1996 - 2004 SN95 Mustang -General/Talk-' started by Flghtmstr1, Sep 3, 2010.

  1. It has been an arduous, long, slow process (with a new wife and new house pushing the Mustang to the back burner), but here are some updates.

    I finally got it on the dyno a couple of weeks ago, and it put down 655 ft-lbs of torque at around 2500 rpm (as soon as the throttle hit the floor) on its first pull. It was making about 19.5 psi of boost on 93 octane, which is pushing it. We splashed some VP 110 octane into the tank for safety, and Jon set the rev limiter higher for a max power pull.

    Alas, it only made 550 rwhp at 5500 rpm. Jon cut the pull off early, as he saw the power and torque dropping dramatically, and we all heard a pronounced change in engine noise. As it turns out, the valves floated around 4150 rpm, as you can see by the inflection point in the hp and torque curves:


    Needless to say, I was bummed, almost to the point of denial. I drove it home, and the first thing I did was a leakdown test. No cylinder had any measurable leakdown, so I dodged a bullet there. I then pulled the valve covers, and called Modular Head Shop as I was supposed to received Stage 3 valve springs with my heads. After consulting with Jordan, we determined that they inadvertently used Stage 2 valve springs when building my heads! They handled the situation admirably, however, and sent me the correct valve springs with no questions asked and no out-of-pocket expenses for me.

    Of course, actually installing the new valve springs was up to me. I don't know how many of you have swapped valve springs with the engine in the car, but it was a ****. It took about 6 hours with a helper.

    The car then sat for a few weeks, until yesterday when I finally had some time to put things back together again.

    I got her buttoned up, and turned the key. It lit off for a few revs, then died with a loud grinding noise. My wife, who was watching the engine bay for leaks / smoke / fire, nearly jumped out of her skin lol. After racking my brain for a few moments, I realized the horrible truth:

    I left a rag in the intake! With a pit in my stomach, I tore into the Mustang again. I eventually reached the TVS's gaping intake, and found some tattered rag fragments to confirm my worst fears. The engine was seized at this point.

    Thinking it was the only way to potentially salvage my engine / supercharger, I took the drain plug out of the blower, took the snout off, and inspected the gears that keep both rotors meshed. The driver's side gear had three dowels on it that the snout engages to drive the supercharger. A lightbulb went off in my head, and I dug around for a tool I had used to change my Miata's timing belt. As it turns out, this tool had two holes drilled in it that were exactly the same distance apart as two of the three dowels on the TVS gear! I placed the tool on the dowels, grabbed some gloves, and pulled on the tool counter-clockwise to attempt to untangle the rag from the TVS's lobes. After what I thought to be more than enough force, the blower turned backwards just enough to expose a large rag fragment. To make a long story short, I was able to use a combination of my fingers, my wife's (thinner) fingers, an intentionally blunted 90 degree pick, and a flexible claw tool, to extract all rag remnants from the supercharger. When it finally spun freely (more-or-less), I put everything back together, and fired the Mustang up again. It ran! I immediately took it out on the nearest highway to confirm it still made boost, and amazingly, it did.

    Those TVS blowers are tough sons of ****es. I can't believe it wasn't damaged, but all seems to be well. Next step is to put it back on the dyno and see how much it makes on a clean pull. Then, it's off to Cecil!
    tank_567 likes this.
  2. Holy f+ock-o+u man. You got lucky as hell. I would never have thought a screw type blower could survive such a thing. Super glad that it did and worked out for you though. :nice:
  3. wow.... the car gods were smiling on you brother.
  4. You're not kidding. I thought it was a goner for sure. I wouldn't be surprised if this incident shortened its life, but I'm sure I'll be looking to get something even bigger down the road :)
  5. My toes curled when i read the stuff about realizing that you left the rag in the engine.
  6. I don't think the engine had a chance to fully light off before the rag gummed up the works. Therefore, the forces were lower. Also, the supercharger drive belt would have slipped to "ease" the stoppage, further cushioning the blow. Still, it was pretty violent.
  7. could have been worse....could have been a wrench. :shrug:
  8. Awesome build, holy pucker moment with the rag! Glad it worked out though :)

    Sent from my MB886 using Tapatalk 2
  9. Crazy story! Happy to hear all is well, hope to see new numbers soon.:nice:
  10. Yea, looking forward to seeing new numbers.

    That being said, don't get all bummed out if the dyno numbers aren't what you want them to be. Automatics don't always tell the whole story on a dyno. Use the track to see the real performance gain. My car still only makes about '340' rwhp on the dyno, but my last time out at the track, it was trapping just shy of 120 mph at 3600 pounds. Do the math, and that comes out to around 510 hp at the motor, which comes to around 425 rwhp on a manual car that shows all of it on the dyno. WAAAY more than what my car does on the dyno.

    Also, how are you getting a pull started that low in the RPM? Every time I've dynoed, the converter would unlock if you went WOT less than 3500ish RPM.
    tank_567 likes this.
  11. Sneaky,

    I appreciate that the dyno results might not be what I'm hoping for, but I'm okay with that. My goal all along has been to build a fun, daily-drivable monster that can blend in with rush hour traffic yet unleash hell when you put the right pedal down. From the disapproving looks I've received from hybrid drivers and expletives screamed by those who asked for joyscare rides, I think I succeeded :)

    Besides, it has already exceeded my expectations with regards to torque. If I can get a clean pull to 6500 rpm, it'll surely be in excess of 600 rwhp.

    I do agree that your trap speed sounds really high for 340 rwhp. With the Tork Tech MP112 kit, I was only trapping 113 with 386 rwhp through my stock 4R70W. I'm not sure the trans is the culprit, however. I would just chalk it up to different dynos, different days, and different tuners. Clearly, your car is running well, and that's all that really matters.

    As for the low-rpm dyno pull, Jon has a special "dyno mode" tune that locks the trans in 3rd with the torque converter locking up at a low wheel speed (maybe 15-20 mph).
  12. A long-overdue update: the car has been re-dynoed and run at the track. To make a long story short, the dyno was still a mixed bag, as even with the new valve springs, the valves still floated (albeit at a higher rpm). The car put down 600 rwhp and 640 rwtq, but this time at only 15 psi. The valves floated at 6000 rpm, so there should still be a lot of power in this combo if I can figure out what's going on.

    At the track, though, the car is running great. The tune is set to shift at 5800 rpm, thereby bypassing the valve float issue. I made the first two passes yesterday, and the car really ripped:



    This is at full street weight and trim, with full interior, spare, jack, swaybar attached, street tires, and full tank of 93 octane. I literally drove the car to the track, pulled up to the line, did my burnout, and went for it.
    #92 Flghtmstr1, Nov 22, 2015
    Last edited: Nov 23, 2015
  13. Nice! [emoji106]

    It sounds like you need stiffer valve springs. It will be interesting to see how much farther it can go once the valve float is resolved.

    Sent from my Nexus 6 using Tapatalk
  14. nice times!!

    question, why didnt you opt for the Trickflow heads?
  15. They didn't exist when this build started. If I were to do it all over again, I might. Then again, I might not, as I wanted to see what factory heads would do, and the Trickflows are twice the price.