2,000 dollars later...
you're missing my point. yes. where he stands right now, it would be cheaper to go with a tvs instead of spending 4.5k on a turbo kit. but had he not spent all the money trying to mod the m62 in the first place and just went right with a turbo. this thread would be about why he only hit 399 and not 400. instead, he's at 255.
I have given up on my stock supercharger, hopefully this summer i will be doing a turbo swap. I have a 2.8, dual pass, s3 heat exchanger, header, catted d/p, 75% meth, zzp intake, option b, phenolic spacer and the stock exhaust with a magnaflow muffler with a byt tune and I only put down 276hp & 256 tq. There are a few other things I can do but throwing another $1k isn't gunna get me to 300whp so I'm saving and gunna turbo so I can get to 400+!!
Did 250whp on my LSJ with $600 into it, using the GMS2 3.06" pulley/stock exhaust. Never dyno'd with 2.9 and additional mods.
Then I went LNF, sunk a bit more in but also achieved what I was seeking. Looking back I'd been wise to keep my SS/SC and turbo swap it, but meh, 5 doors of fun isn't bad either.
Then I went LNF, sunk a bit more in but also achieved what I was seeking. Looking back I'd been wise to keep my SS/SC and turbo swap it, but meh, 5 doors of fun isn't bad either.
Some people like Superchargers, some people like turbos. Who cares?
Everyone knows you need to raise the octane value of the fuel to make big power with a blower. If you can't run 23-25* peak timing on any SC'd LSJ the car will be a turd. Plain and simple.
Everyone knows you need to raise the octane value of the fuel to make big power with a blower. If you can't run 23-25* peak timing on any SC'd LSJ the car will be a turd. Plain and simple.
Ive attached a dyno sheet as the beginning of this thread, take a look at it and hopefully it works.
So, i want to get my 07 cobalt ready for a TVS. thats been my goal all along. So first thing this morning, zzp 3" cai, stock tb, 2.8" pulley, dual pass, option b, zzp stg 3 he,zzp phenolic spacer, 80# injectors, zzp long tube header with catted dp, 2.5" gmpp performance exhaust, custom gremlin85 tune. car puts down 248/251. At this point we swap out the stock blower and intake manifold for a ported and polished m62 with a 2.6" pulley and a ported single pass intake manifold. after retuning and several dyno pulls she has gained 7 horse and lost 6 foot pounds of torque. we tried advancing the timing only to gain 1 hp per point and decided to dial it back to the last point when we made measurable gains. now running about 19 degrees of timing and an excellent a/f ratio. had timing up to 21 with no gains. with the exception of trading the stock h/e for a griffin ive now done every cooling mod short of active intercooling. iat2 temps we only a few degrees above ambient and returned to that point instantly after letting off the throttle. there is nothing more to be gained on the intercooling side. boost before todays mods topped out at 16 or so, after mods, confidently rises to 18.
so, long story short, 2,000 dollars, 6 weeks turnaround on the parts, no butt dyno change, idle is slightly deteriorated. a bit irritated about that actually. for having 80# injectors her idle was excellent yesterday, today its a bit lumpy, otherwise runs excellent. Sounded excellent on the dyno, pulled confidently, no belt or clutch slip. tc rims and tires gripped the dyno without difficulty. Merges onto the highway like its being shot out of a catapult. destroys the tires in first and second gear.
debating the next step. also had a ls4tb and adapter plate ported and polished, going to order a new zpp 3" cai so they can be bolted up and tuned. considering getting the catless dp from zzp. looking for thoughts from the brotherhood. My gut says shes not making what she could. considering a full zzp 3" exhaust, fred at smg says its not needed for anything under 300hp. looking at meth for the spring, already bought a second head to have ported and polished and to in theory get cams for.
So, i want to get my 07 cobalt ready for a TVS. thats been my goal all along. So first thing this morning, zzp 3" cai, stock tb, 2.8" pulley, dual pass, option b, zzp stg 3 he,zzp phenolic spacer, 80# injectors, zzp long tube header with catted dp, 2.5" gmpp performance exhaust, custom gremlin85 tune. car puts down 248/251. At this point we swap out the stock blower and intake manifold for a ported and polished m62 with a 2.6" pulley and a ported single pass intake manifold. after retuning and several dyno pulls she has gained 7 horse and lost 6 foot pounds of torque. we tried advancing the timing only to gain 1 hp per point and decided to dial it back to the last point when we made measurable gains. now running about 19 degrees of timing and an excellent a/f ratio. had timing up to 21 with no gains. with the exception of trading the stock h/e for a griffin ive now done every cooling mod short of active intercooling. iat2 temps we only a few degrees above ambient and returned to that point instantly after letting off the throttle. there is nothing more to be gained on the intercooling side. boost before todays mods topped out at 16 or so, after mods, confidently rises to 18.
so, long story short, 2,000 dollars, 6 weeks turnaround on the parts, no butt dyno change, idle is slightly deteriorated. a bit irritated about that actually. for having 80# injectors her idle was excellent yesterday, today its a bit lumpy, otherwise runs excellent. Sounded excellent on the dyno, pulled confidently, no belt or clutch slip. tc rims and tires gripped the dyno without difficulty. Merges onto the highway like its being shot out of a catapult. destroys the tires in first and second gear.
debating the next step. also had a ls4tb and adapter plate ported and polished, going to order a new zpp 3" cai so they can be bolted up and tuned. considering getting the catless dp from zzp. looking for thoughts from the brotherhood. My gut says shes not making what she could. considering a full zzp 3" exhaust, fred at smg says its not needed for anything under 300hp. looking at meth for the spring, already bought a second head to have ported and polished and to in theory get cams for.
I would have been more than happy to take a look at it for you if you were at all disappointed with the tune. I know I still had some work to get the AFR and trims perfectly spot on but after you swapped the supercharger and whatnot and picked up such small gains, I feel that something might be wrong elsewhere.
Let me know if I or James can help you.
This sounds like it could be 4 things, starting with the worse case.
Cylinder that is starting be be weak (compression in the 140 range)
Slipping clutch
Poorly tuned spark table (tune to knock limit and/or mbt in all cells on dyno, then see what the car feels like
)
Too much fuel
Cylinder that is starting be be weak (compression in the 140 range)
Slipping clutch
Poorly tuned spark table (tune to knock limit and/or mbt in all cells on dyno, then see what the car feels like
)Too much fuel
the a/f ratio is visible in the dyno sheet, it was dead on at about 11.8-1. there is no power balance issue or misfire that would indicate a cylinder that was weak. excellent oil color and smell, excellent exhaust smell, no sign of anything going on with the motor. clutch is possible, its something i should do as her power level climbs. Gremlin your tune was excellent. id very much like to get you back in the copilot seat for a second opinion and to get her logs into circulation to see if theres anything out of place. Her first pull was on your tune and her af was excellent and made exactly the right amount of power for her mods in my opinion. its the after parts install number that bothers me and fred. with a ported and polished blower running a smaller pulley and a ported single pass manifold i was hoping to pick up between 20 and 30 hp. single digit gains bother me when shes picked up 2 pounds of boost.
i was never bashing it. you said that you will make 300-350whp easy with the tvs. i simply said or go turbo for the same price and make ATLEAST 400whp easy.
Last edited by EXsoccer1921; Dec 29, 2011 at 04:35 PM.
my car will have her tvs at some point, there is no doubt. its been the plan since before i bought the car. only thing im debating at this point is wether or not to have my spare head ported, polished, sprung and cammed first. then the next question is meth before or after the tvs.
yes to the head, yes to the meth. unless you tapped the intake manifold for the meth nozzle iirc the only option is with a tb spacer or run it in the intake. i wouldn't do the intake cause when it hits the blade it will deflect and have the possibility of pooling up. with the blower spacer i don't know if theres enough room with how close the tvs already is to everything.
