phantasms

As some of you may know I'm heading to the strip in a couple weeks with the mission of getting my first 10 second slip. I decided to bite the bullet despite all the recent controversy and pick up a Halltech CAI. I figured I may as well pick up a Ported TB while I'm at it as they're such a cheap mod and people say they help with the throttle response which is my biggest and only gripe with the car. The Vitesse does NOT fix this issue...trust me I know. I decided to go with the Katech Ported TB which was about $230. They're probably all good but I went with them just cause they're a name I know.

My intention was to get the car on the dyno, install these two items, race, and get back to the dyno the end of September. Minutes before I left my house the brown UPS truck O' fun stuff rolled up with the TB. I grabbed it and my son and headed out.

As I had a baby in the car I didn't drive hard at all during my 28 minutes to get to the dyno. I got there a little before 15:00 and the first pull took place at 15:18. It was stupid hot and humid out today and the car was on an AWD Mustang Dyno surrounded by Subarus. For the record the car is a M7 Z07 with a Borla off-road X-pipe, 93 Octane, and 29,000 miles. All pulls were in fourth gear and corrected. Figure 20 minutes to cool down from a very easy drive.

The first run put out 552rwhp and 601rwtq.

He said something had happened with the RPM on the dyno which is why the graph looks a bit funny. I have no idea what he was talking about but I don't believe it messed with any of the max figures. One or two more runs were done with it in the same condition and the initial run was the strongest.

They were nice enough to install the TB for me as I was busy walking my son up and down the dyno ramps to his absolute delight. While they were installing we were chatting about the TB. None of us really expected any kind of gain in power. I explained I was just trying to make that throttle a little sharper and wasn't even sure it was going to work. My goal was simply not to lose more than single digits of power. That was honestly my mindset and probably the guys spinning the bolts too. At 16:00 they did another three pulls with, now with the Katech TB installed. Car had about a half hour to cool down after running it hard three times on the dyno.

The first, and best, run put out 571rwhp and 607rwtq. A gain of 19rwhp and 6rwtq at the peaks and more, especially tq, along the curve. Each additional run put out slightly less power as she grew hotter and hotter. We were all totally shocked. The head guy who examined the two TB's said if that little lip made such a difference than a CAI is going to be interesting.

I went on to change a **** diaper, pay the people, and headed out. Immediately I noticed the throttle was sharper. I couldn't believe it. I'm certain that the throttle response issue is in the tune and so I wasn't really expecting much out of this thing. I only did it because some people said it's good and I want to get all the air I can into the car at the track so I can test my theory of the car getting too much air in negative DA. I'm not going to pretend that my *** is special enough that I can feel such a slight percentage increase in power, but I definitely noticed that crisper throttle in Touring, Sport, and Track. Is it perfect? No but it's much better and good enough I can probably accept it now. Of course I didn't drive hard with the baby in the car but I did crack crack that throttle like nobodies business. It will be interesting to see if the CAI plays any roll in the throttle improvement. As far as power of course I'm not expecting another 40rwhp or whatever on top of that. I know this isn't NOS sticker math here.

So in conclusion a ported TB is a no brainer. It's a little over $200, gives a very surprisingly good boost in power, helps a lot with the throttle, super easy install, and is probably the only mod even more warranty friendly than a CAI. It's invisible!

A couple questions as I'm not a dyno master. First off is that a normal look for the AFR? They stuck it in the left most exhaust pipe if it matters. The shape is the same pre and post TB but I don't recall seeing such a shape before. Is it due to the scaling of the axis? What's technically going on from a tune/engine perspective to make that line like that? The other question is why the large difference in hp vs tq on a 650/650 stock car? I'm not concerned I just want to learn.

Any questions? Any comments?

Charts below...

Best,
Gene

Best before vs best after


Three after runs


Best of the day

dvandentop

Damn times flies I remember when u picked up the car your wife was preggers haha. Son is getting big.

That is a great addition for the throttle body only sounds a great bolt on for sure. Wish the air intake had shown up as well to do it all on the same day.

Thanks for the info

four0nefive

Interesting that you did gain power with the TB. I guess it's a good mod for any of the racers/track guys here.

ktoonsez

First off is that a normal look for the AFR?
Depends on the shop, some have a wide band and some don't, all the good shops will have it.

The shape is the same pre and post TB but I don't recall seeing such a shape before. Is it due to the scaling of the axis? What's technically going on from a tune/engine perspective to make that line like that?
The line is pretty normal for the C7, the slope downwards that starts around 4000 RPMs is probably the cat over temp protection that occurs every single wide open throttle run.

As far as the gains go, that is a little shocking on how much you gained, it should have produced gains since it will let the air flow better thru the opening and you can see it effected the AFR a little running a little leaner in a few spots that will make the horsepower jump.

JerriVette

Nice to see you and your son are having some fun together. Congrats on showing the modification improvement

Thanks for sharing

3 Z06ZR1

Nice results! I think the extra 40 will still come with the intake! Car looks much better in all black!

phantasms

Thanks man. Life is accelerating for sure! I'll get back there once the CAI has some miles on it to adjust.

If I had known I would have done it sooner!

Thank you for your continued expertise in all areas technical. What's the deal with the large difference in hp and tq you think?

That's what it's all about.

Thanks man. It's MUCH better in black. I certainly hope your right on the CAI! 60rwhp total would be crazy but then again 2016 is the year where things happen that make zero sense.

Best,
Gene

pelotonracer2

Very impressive!

OnPoint

Will the TB + the CAI lean you out too much?

phantasms

Good question! Anyone?

ktoonsez

Of course I can't come right out and say it won't go too lean, but the cat over-temp will always drop you down to low to mid 10's AFR making it still be crazy rich.
Plus the fact that the PCM tables are in place for more air.

Halltech

Somehow I always thought you were an old guy like me!

Good grief, I hit 70 this month.

jklein7

I would think the TB and CAI would require a change in the mass air calibration and a tune. This is definitely going to push a lot more air into the supercharger. Definitely expect further rwhp gains with that set up. I think but am not sure that the dyno is correct for our cars. May need a tune.

rbartick

HP is Torque over time and the graphs will always cross at 5252 RPM. I think the exact formula is HP = Torque x RPM ÷ 5252.

Swapping parts and doing an immediate dyno run is not a really good way of way of measuring the end results. Your RWHP may change after the STFT and LTFT settle in after driving for a while.

tail_lights

Interesting! Guess I'll add another mod to my 'to do' list

Higgs Boson

surprisingly good results on that dyno run! typically TB's dyno about 4rwhp.

DRLC5

I had both no issues at all. About to buy another ported TB I may go with Katech?

sunsalem

Thanx Gene.

Great story and pics.
Good luck in your quest for 10s.

10-7 OD

OP, I used to own a Mustang AWD-500 chassis dyno. It looks like they tried to use an inductive pickup clipped onto a plug wire. Very hit or miss way to measure engine RPM. Thus the lack of a smooth curve. The better way is to calibrate RPM from rear wheel speed. For example, put the car in the gear you want to do the pull in, then hold it at 3000 RPM. Then tell the software you're at 3000 RPM. Done. Works very well. I had to do that a lot on newer Ferraris. If you get wheelspin on high power cars, add weight over the wheels or drop tire pressure, or cinch down straps tighter.

David@MMS

with all due respect. there are differences just that great in power from the 45min cool down alone.

there is quite a 'step' in the lip of the throttle body gm put there on purpose to settle down the off idle throttle. companies are even adding this back in to aftermarket tb's now, and leaving the 'step' alone when porting

smoothing it i got no problem with it does give the feeling of more power, (it is just giving you more throttle sooner vs. your foot position) but removing it completely i don't suggest. true gains only measured wide open hot to hot, which im sure there is something there but probably not as much as we'd like.

here is a pic of a port job similar to what i did to my own, this one from VMAX i think, where the lip was not simply ground off but the sides smoothed



jus trying to put some info out there, as a lot of people would immediately go to grinding this off, thinking how silly gm was to not consider it. (they did) removing this lip may give unexpected side effects.

here (not c7) but examples of how major aftermarket manufacturers understand this as well.


as the hp goes up and the need for larger throttle opening goes up, the off idle transition just begins to allow too much air, too fast for most non-drivers