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Project Sunbeam Update

Discussion in 'Modified Alpine' started by afssanders, May 16, 2011.

  1. afssanders

    afssanders Donation Time

    It's been awhile since I posted, so I thought I'd give you guys a heads up. I probably won't be making it to the reunion unless a small fortune lands in my pocket.
    I got about 500 miles on my car. I was tuning and driving it. It goes down the road like a new car. Nice and tight, in fact, a little too tight, but it' starting to loosen up.
    The gears that were in there were 3.42, but after driving it. I changed them out to 3.73.
    I was running 4 lb of boost for awhile, then 8 for a couple hundred, then I put some more race gas in there and went to 10. I think you see where I'm going here. About a week ago I thought to myself I might as well see what this race gas can do. I was watching for a knock under labor, but nothing, so I took it to 12 pounds of boost, then 14, then 16. By the way. It goes extremely fast at 16 lb. of boost. Scary fast :). I love the feeling. Any little bump or pebbles on the road will get those rear tires spinning. And that turbo sounds like a jet. No turbo lag what so ever. 9.6 to 1 compression doesn't hurt either. Can't hammer it in 1st. All it does is sit there and spin. You have to let up to get traction. It's just unreal.
    A couple days ago my kid stopped by. He wanted to show me his new car. After looking it over I asked him if he wanted to go for a quick spin. I said I made some changes. He smiled and said. Let's do it. We headed out to Afton, then it started to mist a bit, so we turn around and took off. I took it easy until 3rd, then I hammered it down. The boost shot up to 18 the rear tires broke traction and she got a little squirrely, so I let up and through it into 5th. About three miles down where it was dry we came to county road 19. A four way stop. Took it easier in first and hammered it down in second the tires started spinning the tach pegged at 7 and boost last I saw it went up to 22 pounds of boost and that was all she wrote. The Kid asked what happened? I said we just blew the motor. He said really? I said yep.
    I was just going to put a new short block in it and keep it below 12 pounds of boost, but then I started thinking. It's way too much fun at 18 pounds +. It would be nice just to build around the turbo, so this kind of thing will never happen again, so I started digging and found the parts. They're very expensive Cosworth parts. It'll be worth the wait.
  2. RootesRacer

    RootesRacer Donation Time

    Thats a lot of boost for that compression ratio.

    What kind of timing were you running at 22lbs?
    I'll wager you burned holes clean through the pistons.
  3. afssanders

    afssanders Donation Time

    Well. It was a gradual increase up to 36 degree at 3 grand, then it stayed there. It didn't need to get retarded until 7 pounds of boost on 91 octane. I figured that out on hills out in Afton climbing hills in fourth. Id get half way up the hill and throw the hammer down and wait to see if I got a K value on my ECU. The K next to the timing means that it senses a knock. I had my knock sensor set pretty sensitive too. The ECU was also set to retard the timing 3 degrees for every knock sensed. After 7lbs for every pound of boost I retarded it 3 degree. That's on 91 octane.
    All rules changed on 110 octane. I never even saw a K value, but I knocked 10 degrees off at 14.6lbs. and I let the computer take 3 degrees away for every knock sensed. The thing is just remembered. I have a 1 bar manifold air pressure sensor. I' going to need to talk to Barry at RaceTech about that. I wonder now what really happened. I never thought I would go above 16 psi when I order my ECU setup. I wonder what the ECU thought about 18+ psi.
  4. RootesRacer

    RootesRacer Donation Time

    If the ECU was the typical 2 bar unit, it didnt know the difference between 16psi and 22psi. That is the pressure transducer was probably railed.

    Most high compression engines end up running about 10 degrees at 15psi, that is those running on pump gas.

    Cos parts wont keep the new motor together with the wrong ignition timing so be warned.
  5. afssanders

    afssanders Donation Time

    I must not be running the type of ECU you think, because my MAP sensor isn't part of it. It's a separate unit and sits outside the ECU. There is only one ECU offered up and three pressure ranges of MAP sensors that he offers. I bought the 1 BAR. I'm going to have to order the 2 BAR now. While I have him on the phone I'll ask him what happened above 15 psi. You're probably right. It just remains the same value.
    My timing was 36 BTDC, then I knocked off 10 degree at 14.6 pounds of boost, that brought my timing down to 26 degree before BTDC. If it sensed a knock I had it programmed to take an additional 3 degree for every knock sensed. I'm pretty sure it was the 22 plus pounds of boost that did my engine in. Not preignition. I had a factory engine with factory rods and pistons. No one that I read about has even come close to 18 without it blowing up. 12-14 is pretty much max for that engine. Oh yeah. By the way. I was running 12.5 to 1 air fuel ratio too. A bit rich, but I noticed at 18 psi if I went any leaner it sensed a knock. Like I said before. I had my knock sensitivity set pretty high, so just about any noise it'll pick it up.
    I realize Cossy parts aren't indestructible, but they're the toughest and best poop out and they're also the only pistons I found at 7.3 to 1 compression ratio. I'll be running more boost next time out.
  6. Jim E

    Jim E Donation Time

    Must remember you can blow anything up... stick a used short block in it limit the boost and then look to go nuts. just sayin
  7. RootesRacer

    RootesRacer Donation Time

    The MAP sensor IS a part of the ECU, its just a remote sensor just like the TPS and other sensors. The ECU MUST know what the range of the attached MAP sensor is hence the ECU is setup for whatever MAP sensor you are intended to run.

    20psi is 2.5bar absolute (1.5 bar gauge) so if you have a 1 bar ECU (meaning a 1 BAR sensor on your ECU) then you need to determine if it is 1 BAR gauge or 1 BAR absolute. The difference in nomenclature is important as this allows you to determine the max that the mapping for fuel and ignition can go.
    If the MAP sensor is out of range then there is no map data to correctly fuel or run ignition timing. From that standpoint the ECU could not tell the difference between 20 and 100psi. It is open loop.

    Not sure what ECU you are running but unless its a stock ECU running a very stock engine, the knock detecting is as good as USELESS.

    Pre-ignition is NOT the same as detonation, one comes from a hot spot, the other from an early spark event.

    12.5 AFR is not very rich, particularly at 20psi boost.
    12.5 AFR would be OK for a naturally aspirated engine, but at 20psi most folks run 11 to 11.5 AFR. This keeps the charge cooler and slows down the flame front which helps prevent knock.

    When you tear your motor down I think you will find melted pistons to say the least.

    You very much need to get a handle on this stuff now or you will repeat history, this time with a much more expensive engine.

    If you need any advice I'd be happy to help.
  8. MikeH

    MikeH Platinum Level Sponsor

    A friend of mine suggested that the waste-gate was too small for the amount of boost.
  9. afssanders

    afssanders Donation Time

    I wouldn't buy a used short block. It just would pay when I can buy brand new for 725 delivered.

    I'm using and programed my Simple Digital System ECU. They're made in Canada. Pretty pricey, but good stuff. Im sure you've heard of them. I've already had a look at the piston through a nice big holes in the oil pan. The rod was ripped loose from the piston. No hole. Ive been around the block long enough to know this was a result of too much power.
  10. RootesRacer

    RootesRacer Donation Time

    OK good luck with that.
  11. afssanders

    afssanders Donation Time

    Just got off the phone with Barry. Turns out I have a 2 BAR sensor. Anything above 15psi and it stayed at where I have it set. Which in my case was 36 to begin with minus 10 (my setting at 14.6psi +) = 25 degrees BTDC when it blew. Unless it sensed a knock, then who knows. He going to send me a 3 BAR sensor and instructions on how to reprogram the ECU for increased manifold pressures.
  12. RootesRacer

    RootesRacer Donation Time

    Which means that you also had no extra fuel from 15 to 22psi which would have run pretty darn lean there.

    Dont trust your SD ECUs ability to detect knock, it wont save your next motor as it cant tell the difference between wrapping a wrench to the block (or valve clatter) versus actual knock.
  13. afssanders

    afssanders Donation Time

    Yeah. I'll be remapping the entire deal before thrashing it again. It's a slow process as I'm sure you're aware of. I'm also going with 7.3 to 1 piston this next time around too, so that is going to change all the rules. The new Cossy block will have piston squirters and billet mains. Good and bad, but I figure Cosworth and Ford have invested millions in this set up and have engineers that know a lot more then me, so it's not like inventing a new wheel it's been done. I'm just buying it. My GT28R turbo just won't have enough power to blow it up. Also it's not like I'll be hammering on it all the time. I'll be able to run 87 octane and up. I can even throw some E85 in there if I want. I'll just have to keep a log book to reprogram the ECU for the gas and boost I choose.
    You might find this hard to believe, but I knew it was going to blow. I just didn't know when it would happen. I just needed to know the limits of a stock Zetec block and parts within. Stock. If a person has it setup right 12 pounds is pretty dependable. That's on 96 octane. 91 octane 8-10 pounds is pretty good. And don't me wrong. It's pretty damn fast at those boost levels, but MAN 18+ is unreal power. I got to have it again.
  14. jammont

    jammont Donation Time

    Sunbeam project

    Would like to see some pics of your car.......do you have some.....
  15. afssanders

    afssanders Donation Time

  16. jammont

    jammont Donation Time

    sunbeam project

    nice........looks like alot of customizing....is it still on its original frame
  17. afssanders

    afssanders Donation Time


    You could safely say it the worlds most modified Sunbeam. That other one isn't even close to what I've done.

    It's the original unibody. No tubes and anything like that. I did however channel the front end 2" All the travel with a nice low look. No banging down the road.
  18. jack Bacon

    jack Bacon Silver Level Sponsor

    Hi John,

    Sorry to hear the engine blew on your car. You could come to the Invasion with the car on a trailer. It would still be great for everyone to see all the mods you have done.

    If you don't want to bring the car still come to the Invasion.

    Best regards,

  19. afssanders

    afssanders Donation Time

    If I remember right it's in Sept. I might have it back to gather by then. I'll be digging into it again here shortly. It doesn't take me long to do stuff. The 4000 for the block rods and pistons are a big set back though. However the nice thing about it is it'll give me time to get all the odds and ends finished up. I look forward to tearing into it again.

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