LLY: my custom big twins build
- Thread starter duratothemax
- Start date
Very nice job, Ben. :thumb: Man, you take huge pics.
I have a couple questions. The bar running from the 480 exhaust housing to the alternator area....wouldnt that clear the I/C pipe by a lot more if you flipped it around so the welded bar is on top, not bottom? Maybe just run the flat stock all the way? Just curious. Also, what are the plans for an intake?
I have a couple questions. The bar running from the 480 exhaust housing to the alternator area....wouldnt that clear the I/C pipe by a lot more if you flipped it around so the welded bar is on top, not bottom? Maybe just run the flat stock all the way? Just curious. Also, what are the plans for an intake?
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my twins are not loud either with the s480 w/john deere cover. The garretts shriek louder. How is back psi? its probably high because egts are up too.ok I just went for a test drive. I think I might have some boost leaks but Im not sure.
Otherwise no leaks/funny noises/pipes rubbing on anything/parts coming loose.
Its definitely going to take some tuning to make this big (sorry, bigISH) turbo work. The MPI twins were small enough so it was bolt on and go and they worked great. Im not sure if the S480 is even really spooling?? HeepJeeps has my boost gauge sensor (we forgot to take it off my piping when we put my old twins on his LBZ) so other than looking at the map sensor reading I have no idea what its doing for boost.
So yeah, initial impressions/thoughts...not really impressed.These twins arent half as loud as my old MPI twins either.
I dont know why the MPI twins were so loud but my S480 twins have nothing on them. You would think bigger turbo, even louder but I guess not.
I also STUPIDLY forgot to weld a bung in the cold pipe so I can see what the pressure is between the two turbos. Im not going to wreck my 'nice' paint job so I might either drill and tap the compressor housing of the S480 or drill/tap the mouthpiece going into the stock turbo.
Its also pouring rain here. Hasnt rained in probably 2 weeks and the day I finish the damn thing it turns into a pond here. Great.
I did try a somewhat decent sized tune, I think its 2000us and like 16* of timing (remember I have big dipper injectors) and it really took off..it was kind of scary. The completely stock LLY tune (well, stock plus the injectors) that Ive been running 99% of the time worked great on the MPI twins; it was fun to drive, spooled fast. The stock tune kinda sucks on the S480 twins... EGT's are kinda high too. I mean not like "high high", but high for twins.
So like I said, I think ill have to play around with tuning on it before it really starts to work well...
ben
The 480 is too big for what you're after IMO..........People always think bigger is better, but it's just more to spool. Looks good, dump some fuel to it now
Keep looking Ben , something doesn't seem right , granted i had a s366 up top but my 480 twins spooled way wick ,and EGT's were in the 1300-1350 range on a mid 11 sec pass ( single cp3 ) around 1150-1200 deg on a pulse similar to slightly bigger than what you are running now .
The 480 is too big for what you're after IMO..........People always think bigger is better, but it's just more to spool. Looks good, dump some fuel to it now
what about if I upgraded to one of those garrett AVNT4094's??
would that twin well with the 480?
well I drove it around more and now it seems better??? Im thinking I still had some air or something in my fuel lines maybe? If the KD pumps run dry it can take a while for them to bleed completely.
It seems to run a lot better now, but I still need my boost gauge. (heepjeep, if you dont get it to me by tomorrow im slashing your tires)
still not loud though, as stupid as it sounds, thats my biggest dissapointment with these twins.
ben
It seems to run a lot better now, but I still need my boost gauge. (heepjeep, if you dont get it to me by tomorrow im slashing your tires)
still not loud though, as stupid as it sounds, thats my biggest dissapointment with these twins.
ben
no idea...I dont have a drive pressure gauge. I might get a cheap one for tuning purposes.
well I drove it around more and now it seems better??? Im thinking I still had some air or something in my fuel lines maybe? If the KD pumps run dry it can take a while for them to bleed completely.
It seems to run a lot better now, but I still need my boost gauge. (heepjeep, if you dont get it to me by tomorrow im slashing your tires)
still not loud though, as stupid as it sounds, thats my biggest dissapointment with these twins.
ben
Once you've had a screamer it doesn't seem the same after.
I'm sure once you get it dialed in you'll enjoy it alot more.Once you've had a screamer it doesn'tW seem the same after.
Whoa we talking about turbos or women?:spit:
an air compressor guage will be fine to use for back psi. You will also need a inline tee valve in there (almost closed all the way, so the guage needle dont bounce around from the exhaust pulses)
Not sure, depends if the exhaust side is larger than a stock VVT. I'd think it would work better if it will allow more flow. IMO the stock VVT turbos are too choked up on the exhaust side to be used in a set of twins with an atmosphere turbo bigger than 74-75MM............Unless you added a wastegate around it:secret:
are there any aftermarket vvt's that are opened up on the exhaust side? I wish I could find more specs about the AVNT4094....
I would really like to keep the VVT...there has to be some way to go big(ER) twins with a VVT.
I do have a wastegate leftover from my MPI twins...hmm. But should I gate around the big turbo too? Im too cheap to buy a second wastegate; with the one I have sitting here what would you guys do...gate around the VVT or gate around the big(ER) turbo?
ben
No need to gate around the 480 , but a gate around the VVT is a decent idea , if your going to run it hard ? if your not i wouldn't worry about it . And on the wistle , it seems the bigger the turbo gets it is more like a Woosh then a wistle then bigger you go . Once agan it looks great Ben , you should be proud :hug:
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