LTG and F40 instead of LSJ and turbo swap?

Discussion in 'Ecotec Platform' started by PMF1, Aug 2, 2017.

  1. PMF1

    PMF1 Member

    Anyone interested in the DF Goblin is all about finding the most performance (fun) in the cheapest package. The cobalt SS route has proven to be a great way to go. I very well may go the LSJ + ZZP turbo swap route with my own build but I wanted to see what other more knowledgeable gearheads had to say about the possibility of using a cheap base model cobalt as a donor for everything but the engine and transmission. Then purchasing a low mileage LTG ecotec found on ebay for less than $2k shipped, and mating it to a new F40 transmission also found on ebay for around $900 shipped.

    So to recap a cheap base cobalt can be had for around $1000. Used LTG turbo engine with less than 40k miles is going for less than $2k shipped. New F40 transmissions are less than $1k shipped. So for $4k plus the cost of parts not included with the engine and transmission (ECU, fuel rails, etc) you could have the parts needed for a low mileage 270 HP, 295 ft/lb goblin with a new F40 transmission.

    Is this as good of an idea as it looks on paper? Why not go the LTG route?
  2. Silverback

    Silverback Active Member

    I'd take an LSD-equipped 5-speed F35 (the G85 option) over a 6-speed F40 without it. But there is a Quaife LSD upgrade for the F40 if you want to spend the money.
    Last edited: Aug 2, 2017
  3. TheNuker

    TheNuker Well-Known Member

    I'm sticking super charged LSJ because after driving the car the SC is going to stay in the power band on the track all the time. I'm planning to put the harrop tvs 1320 on it maybe for next season. But let me tell you stock ish power goblin I dynoed at 228whp it feels order damn great. On the track I was pushing past 911 turbos etc out of corners.

    They only pass you up after you hit 120 and stop accelerating lol

    JSATX likes this.
  4. Andy

    Andy Member

    I got the SS SC stock 200 hp with simple mods and a ECU flash you can be up to 300 with little involved 1000 bucks or so and a mostly stock setup. If you get the SS with a F35 LSD you got a great transmission. All are bullet proof at 300 hp. This car anything over 300 hp would probably be of little gains. With a 300 up car your 0-60 would probably be close to a 3.0. Much faster than most if not all street cars. Plus you have to be very quick to shift to get those numbers. Not saying 300+ hp wouldn't be fun but diminishing returns.
  5. TheNuker

    TheNuker Well-Known Member

    Your not going to get 300whp on stock supercharger on the LSJ, check out the Cobalt SS forums. The blower just maxes out.

  6. JSATX

    JSATX Well-Known Member

    I'd be super interested to see charts if you have any
  7. PHerder

    PHerder Well-Known Member

    BTW, ZZP (and probably others) sell the necessary swap bits to make the F40 work behind the LSJ and the LNF. Different flywheel, TOB. and clutch is what I remember. There may be other bits I am not remembering but I lost interest once I started exploring a F40 swap when I thought my F35 was blown. The threads I read on the CobaltSS forum weren't very kind on the F40 as it was a lot of trouble and $$ for one extra gear that didn't help.

    If you are bound and determined on a F40, source one from a SAAB as they are the same (from what I remember reading) but the cost in the salvage yards was cheaper.

    Again, this is from memory since I stopped looking a couple months ago.


    Another thought on the LTG engine, it was developed as a RWD motor so the mounts for the engine and the accessories may be very different or non-existent.
  8. TheNuker

    TheNuker Well-Known Member

    I'll post the charts next week, I'm going back to have the stage 2 kit tuned after I install it. Should hopefully be pushing around 240-245whp.

  9. JSATX

    JSATX Well-Known Member

    Why not get the cheapest cobalt you can find for the random bits like pedal box, steering etc and then get a Saab 9-3? They are dirt cheap and you're going to need all the electronics out of it anyway. If you get an eBay motor and trans you won't get all the wires needed.
  10. Andy

    Andy Member

    I thought 300 HP was about the top for the stock SC. Could be wrong. I am going to go with stock charger and put a smaller pulley bigger injectors and try for around 250 fast enough for me for a street car.
  11. Silverback

    Silverback Active Member

    Looks like the LTG swaps sides for the intake and exhaust. That'd be a real challenge to fit into a Goblin.
    Last edited: Aug 5, 2017
  12. TheNuker

    TheNuker Well-Known Member

    I guess you can technically get to 300whp on the m62 if you throw everything known to man at it. 2.5-2.6" pully E85 meth injection. But I'd much rather have the TVS 1320 running much less boost much less heat and easily making 310-330whp.

  13. PMF1

    PMF1 Member

    I completely agree. LSD equipped cobalts are even harder to find than a cheap LNF cobalt. I'll definitely want an LSD and from what I've seen this is another reason to go with an F40. A Quaife LSD for the F40 will run you $1100 shipped and is much easier to install compared to an F35. You could get an OBX LSD for the F35 for around $400 although you'll need a bunch of specialized tools to get the job done and material cost will probably run another $50 - $100. I watched an F35 disassembly video someone put on youtube and it was really involved. Probably better to pay the $1k+ to have it done at a shop. The Quaife LSD for an F35 is going for $1100 + shipping from the UK so you're certainly not any better off if you want a Quaife.

    I was thinking the same thing, and while I wasn't able to confirm the FWD and RWD LTG engines blocks were the same, I did find a few places that talked about the oil pan being different between the two versions. It sounds like the LTG is around the same size as the LSJ/LNF/LDK, although it doesn’t share the same mounting points as the older 2.0 ecotecs. That said it does appear to share the same bellhousing bolt pattern as all other 2.0 ecotec engines.

    If you were to go with an LTG you would certainly need to engineer custom brackets and potentially modify the cobalt subframe.

    It would give you a turbo ecotec and F40 already mated, although from what I've seen the cheap 9-3s on craigslist all have a bunch of miles and only have 210 HP, 220 ft/lb max. Might be better to stick with a LSJ with similar mileage. The wiring issue would be another challenge/hurtle. Getting a used ECM would be easy although figuring out to get everything working would take some patients, time, and probably a crap-ton of googling.

    You're right the intake/exhaust has been switched, apparently to be better suited for longitudinal engine placement. This might be the biggest hurdle. I haven't been able to find any examples of how to route the exhaust and turbo pipes in a Goblin-like setup. There is a similar post on a Fiero forum that talks about this being an issue although it doesn't look like anyone has attempted it yet. Someone also posted a link to a great description of the LTG engine and why it's better than the older Ecotec engines. Other than the low miles and price of used LTGs that is.

    After reading up on everything for the past couple days it's looking like a cheap LSJ is probably the way to go for a Goblin build. A DIY turbo swap wouldn't be impossible and would hopefully cut the $5k ZZP price down to $2k ish? I don't see anyway around a high mileage donor motor other than buying a brand new LHU long block on ebay for $3100. Which would be a pretty good option if you found an LNF cobalt donor with a blown motor.

    As far as a transmission goes the F40 certainly seems like a winner from an LSD, reliability, and gear ratio point of view. Although I haven't found a clear writeup of how to adapt the F40 to a Goblin/cobalt setup. ZZP used to offer an expensive kit but it doesn't look like an option at the moment. Seems like a waste to put $2k+ into a used G35 for an LSD, when a new F40 + LSD can be had for around $2100 if you install the LSD yourself. I might get lucky and find a donor with an LSD already installed but I'm not holding my breath. I'll need to learn more about why the F40 won't mate up with a cobalt. Maybe it'll shed some light on how to make it work.
  14. Silverback

    Silverback Active Member

    I'd be hesitant to put a LTG engine with a red-hot turbo right next to a gas tank which is less than an inch away from the cockpit in a car without a rear bumper. :eek:
    Last edited: Aug 5, 2017
  15. PMF1

    PMF1 Member

    A red hot turbo doesn't seem to be a large concern for igniting gasoline. Getting cooked by the exhaust manifold right behind the driver's seat might not be a lot of fun though.

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