75 is actually quite cool, so I don't think that's the case. The pump 91 might have been a factor.

 

Thanks Todd!

 

Well, its not as cool as 40 degrees. My car feels like it has much more torque when its really cold.

Play with this some. Torque will generally increase like hp at lower temps. It just does it at lower rpms.
http://www.csgnetwork.com/relhumhpcalc.html

 

I'm betting the tq is low because of the lack of timing with that much boost?

 

Thats a good point!

 

It's a sacrifice...Boost makes power, timing makes TQ. That was some of my reasoning with the Meth injection. With Meth, much like race gas, you eliminate most of the sacrifice. So I am running 1.35 bar on 93oct, with full timing, with Meth. Those numbers on a TIP is still a fun car. It might last a long time with the lower tq. The high HP doesn't hurt anything.

 

Interesting ttboost.

 

Just an observation....while the torque curve looks nice and smooth, it peaks at 5700 or so? Every single time I've dyno'd my car, regardless of turbo, my peak TQ is somewhere between 3800 and 4500. I'm betting with LESS boost and MORE timing that peak TQ will move down. Even if you make LESS peak hp, the car will feel WAY faster. Does anyone else's Tip car do this? Maybe it's a good thing for his tranny & TC?

 

Eh? Horsepower is COMPUTED from Torque - they are tied together and should cross at 5252RPMs. Tune for highest torque and horsepower follows, it's not one or the other.

Facts about timing and power... Octane changes burn rate, get it high enough to not self detonate and you can increase cylinder pressure further with more boost aka fuel\oxygen. Higher octane burns SLOWER and is less likely to explode which is why it requires more timing. Timing simply changes when the burn begins. Too much timing and torque drops as cylinder pressure peaks too close to TDC, detonation follows a few degrees later. Retarding timing lowers cylinder pressure as pressure peaks with the piston further down the bore. Proper timing gives peak cylinder pressure just after a few degrees after TDC. Advancing timing starts the burn earlier, retarding it puts it closer to TDC. Timing is where you find power by increasing efficiency, A/F doesn't change power much unless there's not enough fuel or there's a lot and you are quenching knock.

Not sure how you got timing making torque and boost making power other than boost usually happens further in the power curve past the torque\HP crossover which makes high torque turn into high HP due to the math involved with RPM. http://www.vettenet.org/torquehp.html An interesting tidbit - peak torque is best BSFC and is generally where there's least timing as the engine is most efficient.

That's from memory but I think it's accurate, been awhile since class! Oh BTW- meth carries oxygen with it which is pretty nice

 

OK, let's be honest, to me, that dyno plot looks like a normally aspirated small block chevy dyno plot, which isn't necessarily a bad thing. But I don't think he will feel the turbo "spool up" that everyone associates with a fast turbo car. IMO, I think he's missing 100ft/lbs of TQ and it comes on too far up in the power band. Why is that? Tiptronic? I understand how hp and tq relate to each other and with more timing they will both go up and still cross at 5252rpm. When I built and tuned my TT Camaro, at one point I was getting as much power from 1deg of timing as I was from 1psi of boost. Heck my car with 18G's, with NO meth, at 1.2 bar made peak TQ at 4200. I know people say the GT28's have "mad spool", but 440ft/lbs of TQ with 1.4bar of boost and not until 5700rpm? How do you explain that? Did they ramp the boost in slowly which can be done with these ECU's. Does he have a boost controller to do it?

I guess my point was and still is, the higher boost on 91 is more of a hinderance. I think the car would make BETTER power with LESS boost and MORE timing, that's all I'm saying. Again, just my opinion.

 

very respectable numbers Eugene

 

Thanks, Rich. You changed your avatar.

Again, very interesting conversation. I don't know much about the relationship between tq and boost; but I do get a pretty good kick when the car spools up and there is pretty much no lag. I know different tuners tune the P-car with with their own philosophy; maybe that's how EVOMs tunes their GT660 package.

Here's the boost chart... please comment...

 

Okay i will honest here as well...that TQ is very very low. Something must be wrong. All i can say is my k16 car with EPL flash only (no other mods) produced 400 HP ,480 Tq on a dynodynamics 70F day. My k16/16G car made 540TQ on a 70F day on dynodynamics.

I thought that might have been limited by tuning to save the transmission.

Dynodynamics usually reads about 5% lower than mustang.

Those are stong HP numbers, but with the TQ fixed...you will feel your car to be much much faster. The overall fun factor increases.

Also a TQ convertor might increase your safety margin , especially after seeing a TIP failure(blackhorseturbo), i see that as a smart move.

 

Thanks vbmw335, my question is does it actually go faster or just FEEL faster. My car drives very much like a NA car with a better kick. And throttling is very easy to control.

 

Yes it will feel way faster and will go faster. Also your TQ starts peaking late...mine with 16g's hit peak around 4500. So yes overall faster and will be a big difference for sure. GT28's are supposed to spool fast and carry power longer as well. I wont speak much about tuning details ...since i am not that good with that stuff...leave the why's and how's to ttboost,blkmgk. All i wanted to do was flag my observations which might help you get some more out of your car safely.

I attached my car dyno on just a k16 Flash no exhaust for your reference. I can also send you a 16g dyno sheet where it made 540TQ with no exhaust.