John Z Williams said:
Ok, one question is at what point would you say its too lean of an a/f mixture?
Anything over 13.7:1 is too lean, thats what I have been told for a FI car.
John Z Williams said:
What is considered the optimal a/f for our cars and would you say its really not safe to hammer my car with it being close to 13/1???
Like said 12.0:1 is optimal. Much less than 11.0:1 is too rich. The down side to too rich is poor fuel consumption and increased carbon monoxide emissions.
John Z Williams said:
Second question is have you had a dyno done in Denver since your mods and turbo upgrades. I would be interested to hear how your car does on the dyno with the gt2871 turbo???
I've dyno'd a few times at various stages, not after the GT2871R mainly because I can't boost past 1.4 Bar in the mid range without serious surge. I've run the car dead-nuts (wastegate closed) and it will get past the surge issues in gear 3 with only a small hiccup at ~4K RPM. Gear four the hicup is longer and more difficult to "power through." No idea about gear 5 as that is approaching 125-140 MPH. Dead nuts it'll boost to ~1.85 BAR and hold steady. I've said it before, but there is no need for this kind of power on the streets. Even at 90-100 MPH the car wiggle-waggles all over the (track) when on full boost, I can light the tires at 75 MPH. :evil:
John Z Williams said:
Third question you answered somewhat. How much trouble is it to get the inlet pipe to fit on the gt2871 turbo with stock manifold?
With my set up there is no inlet pipe. I've welded a very custom aluminum cone-elbow on the compressor housing. see below. There really is no room for a turbo this size. I was stuck on trying to find the best bolt-on for our cars possible as I was trying to bring it to market. That bill is filled by JAK's Big T28. I've not ruled my solution out, but I think it's best to rule out the bugs before I say go either way.
If i only have a software issue then all is good. Everyone will know if this takes place.
John Z Williams said:
Is there an adaptor plate to help with that and what would have to be done to make the exhaust side fit my existing 3 bolt pattern down pipe? Is there an adaptor to make it fit my existing dp that I have now?
I have two, unknown to me, but these things apparently don't exists. We've called all kinds of people including Garrett and they don't have a p/n for them. See what I mean?
John Z Williams said:
Where can I find some of these v-band adaptors that may enable me to use the gt2871 turbo with my stock exhaust manifold???
You can call ATPturbo. However, I would highly highly highly (get the idea?) recommend you don't go this route. This turbo requires a better intake than what I'm using. A 4" necked down to 3" is what I'd recommend. There is exactaly zero additional room for this. Get a new manifold that positions the turbo closer to the battery, allows for a nice 3" elbow for the intake. This will require a new custom manifold, downpipe, and intake. After all the work I put into the manifold and DP I didn't want to have to redo, especially trying to establish the ultimate bolt-on turbo kit.
Here are some shots of the compressor housing pre me toying with it, and how much room there was (none). Note the AC housing is about even with the shaft.
John Z Williams said:
In your opinion, how does that power/torque curve graph look to you?
I really like the pre porting curves. I'm sure you'll be able to get this setup figured out. The first dyno you posted way back when was garbage, the power fell above 5500 RPM and I really didn't like the TQ spike mid range. I'm sure it felt fast, but traction is a royal PITA with a spike like that. No idea what was causing your notchy curves this time. Bad RPM sensor/reading (?)
I hope some of this helps. I'm sure some of it is not what you want to hear, but these are my thoughts/feelings/findings. They may change when I have the time to mess around. Ski season is almost over (only two more weeks) and then I get my Sunday's back.