stkdidy

Ok, first off I apologize to JR for being 30min late, i did not expect the one hour drive to take almost two...

second, here are a few pictures of me on the dyno, and of the throttle bodies (stock vs GMS) side by side, and of the GMS TB installed.

Thank you to to JR, Morgan, and GMS for lending their time pro bono for new mustang enthusiasts such as myself! They were very professional and I was thoroughly impressed with their shop and AWD Mustang Dyno


Me on dyno:


TBs side by side comparison:




this TB does not open past parallel, not that that would restrict very much air anyway:



Installed:



Here are 2 of the 4 pulls done BEFORE the TB (note that they are identical down to just tenths of a hp/ft-lb, and therefore show very well that this is the correct set of numbers for my car beforehand...not just a freak pull):



HERE ARE THE RESULTS YOU'VE BEEN WAITING FOR (before and after comparison, done ~45 minutes apart and in the same conditions...and engine was warm for both). Note how consistant the increase in torque is through all rpm, and the gradual, but steady increase in hp, which may be why many claim to "feel" a lighter pedal:



Here is a better view of it (keep in mind that this was the FIRST run after simply bolting on the TB, as rwtq actually increased more in the subsequent run):



A/F ratio AFTER is essentially 12.5:1 down low and leans out through the rpm range as more air is allowed into the engine, peaking at 13.1:1 (A/F ratio numbers on on the right hand side of the graph):





Now for those who don't use a Mustang Dynometer to measure a loaded application, we did an "unloaded" run. These numbers should be nearly identical to ones that would be achieved on a DynoJet Dynometer (it uses the results achieved by the SECOND pass with the TB on, which means that the results are 10.5rwhp increase over how it used to be, and 13.7rwtq over how it used to be):





Results from driving:
Throttle response is EXTREMELY light now, and the added torque through the whole rpm range can really be felt, i was going 140 before i had any idea what i was doing when i got back on the 101S. the throttle engages more with less pedal work, so it takes a few minutes to get the hang of, but isn't bad or anything....(negatives, see below...)





Now time for the DOWNSIDES:
When you let off the throttle, the car keeps going at the same rpm, much the same way it would if you put the clutch in, put it in neutral, or have an automatic (the "coasting" effect i dub it). It is quite annoying after a while cuz u have to use the breaks a lot more than normal. Fortunately, all this can be solved with a reflash to make the tb close all the way when you let off the gas.

Also, there is a distinct whistle that comes from out of the intake now and takes some getting used to, though it is really not a downside unless you are biggotted against things that whistle, haha.

other than that i have no no negative effects...no CEL or safe mode, no gettting stuck at WOT, and nothing but instant feedback when hitting the gas.




What's the Final Result?
1)GMS dealt with the "challenge" very professionally, and I highly recommend them because of this positive experience
2)when the dust settled, the most rwhp increase achieved by a simple bolt-on was 10.8rwhp, the least measured was 10.5rwhp.
3) the most rwtq increase measured was 13.7rwtq, the least was 12.5rwtq
4)the GMS throttle body worked very well with my JLT intake and SCT2 tune, and more gains might be possible with another full tune
5)I highly recommend you go to your local shop that deals with your tuning program and get some sort of reflash to make it "throttle down" faster after letting off the gas
6)DynoJet numbers are misleading, but make you feel better about yourself when bragging
7)there is a huge party tonight and after a long day of hanging out at GMS, Pacific Coast Motorsports, G.A.S (opens Feb15), and another shop or two, I am ready to let loose in a way that does not involve driving!




feel free to PM me any questions you have about my experience with JR, GMS, or driving with the TB, or feel free to post them in here.


-Geoff Larson

dustindu4

those numbers are great but can't see any pics

stkdidy

I will rehost the pics, they worked the first time i viewed page

korinwoodo

They work for me.

stkdidy

done, hope cardomain doesn't have bandwidth limits.



ANYWAY, in the experience i had, i highly recommend getting a new twin 62mm TB...and i can vouch that the Granatelli unit gained the claimed power, if not more, in front of my eyes.

don_w

Geoff, congrats and thanks for the complete and detailed post!!

rhoover2

Thanks for the WORD. After all the mudslinging that went on in the last thread I am glad you started a fresh one. It was getting messy.

freebass55

Great write up. Thanks.

luckyeod28

I'll ask this to JR as well as the rest of the vendors on this site...

Can we get a group buy going, with a discount because I'm sure that after seeing these results you could sell quite a few.

nonsensez9

cool! another review like that and I'll have my plastic out in no time!

one thing I don't understand: why 2 circles instead of one big oval?

dcranford

I thought the throttle body was mechanical I didnt know you could tune the throttle blades to tell them when to shut?

Is it possible to do this with both the predator and the SCT?

xetrov

I want one. There goes part of the tax refund.

Cleveland

so let me get this straight, these are not properly tuned runs?

Figures...

Why not give actual tuned performance numbers instead of the bolt on potential over the stock TB. Other tuners have found that in the long run (after full and good tuning) the upgraded TB is not worth the same gains when compared to a fully tuned stock configuration. Its more like slim to none.

-Dan

thump_rrr

I don't like sounding like an eternal pessimist but I agree with Dan.

The increase in HP is probably due to the leaning out of the A/F ratio since there was no tuning done.

We need all the pieces of the puzzle for both before and after the TB installation to determine if there were legitimate gains made.

I can lean out my car too and make more hp. The great equalizer is maintaining a consistent A/F ratio.

Why don't we have any A/F readings on the pulls with the stock TB?

I can't even read the numbers on the A/F chart that's there.

That's what's needed to quell all doubts

If both the before and after pulls have the same A/F ratio then yes the TB made more power.

rhoover2

I am just a dumass electrician and not an expert here BUT if I was running N/A with no power adders why SHOULD I expect to see a gain? If my car is already tuned for the best A/F mixture and I just open the throat of the beast a little wider... where is the gain?
Now if I have a power adder.. Then this piece should allow me to stuff more into the belly of the beast because his mouth is open wider.. Right?

Import-Slaya

Reflashing to get the throttle blades to close is easier said than done on the throttle by wire system. So far, from two different tuners, I haven't been able to achieve it.

Doug@C&L

You're kinda right here. Where the actual problem lie's is that the 05-06 Mustangs with Drive-By-Wire doesn't have an Idle air controll valve anymore. So it uses the throttle plate and a HIGHLY researched table to create the dashpot affect for the TB. When you install a larger sized TB you increase the amount of airflow not only while under throttle loads but also when you are of the throttle and trying to slow the engine down.

I have the LFP 62mm TB, that by the way looks exactly the same. Now, with an automatic like mine I've not found this to be a problem at all but I'm assuming the additional load from the transmission is aiding in slowing the engine. With a 5-speed In slowing down situations or depressing the clutch I can definatly see the issue.

An even worse situation is with a Supercharged car, you are not only forcing more air but simply moving more air at idle because the supercharger maynot be pressurizing it at idle but it is working like a $5000 air intake and aiding in getting some air to the engine. I've seen a Vortech S/C car run great under loads but when coming to a stop or even between shifts it goes to 3000 rpm's and stays for a while.

The fix, yes, custom tuning can help to solve this problem and it can be fixed entirly by doing this. Don't worry about dynotime because it's going to be done on the street with a datalogger. No true dynotime needed. It will be a slow process but it can be tuned out and made to perform like a stocker under closed throttle situations.

And as for the slowing effect of the engine with the stock TB, I have a tune that is ALOT better for that with the manual cars. I do it to every manual program I do. It's actually one of the top requests I get from you guys.

Thanks, Doug.

Hatchman

I would like to say, Doug's manual tune rocks.

As far as the TB, I hate to say it, but looks like the gains cam from the A/F being leaner. My car gained 10hp/tq when the tune was leaned out a little too. It is a good looking part though! And as long as you're happy, that's cool!

Granatelli

Thanks for the feedback. To the rest of you as I stated before We will offer the same deal to the next 10 guys that want ot purchase for $389.00 shipped in 48 states

<!--QuoteBegin-luckyeod28@January 27, 2006, 10:30 PM
I'll ask this to JR as well as the rest of the vendors on this site...

Can we get a group buy going, with a discount because I'm sure that after seeing these results you could sell quite a few.

Quoted post

[/quote]

If there is a part that you see on our site or in our catalog just let us know. we will do our best to help you guys out. We believe in supporting our dealers but we also know that promo's help everyone.

Granatelli