I had the privilege of driving a friends GT35/40 car while we were tuning it (I was driving, he was tuning with WB and Datalogit) Now, I'll leave his name out of it until he wants to fess up....since he may not want the publicity right now.

The whole time driving it I was comparing it (mentally) to my seq. twin (which I just finished about 7 tuning runs one...me driving...me tuning). I kept asking myself the questions and making comments:

"Is there really that much difference?"
"How much RWHP is this going to net me where I can feel it, not just on a track?"
"Bah, I can take him if I just get the break!"
"Man, where is the low end giddy-yup?"
"Sheesh, this drives different!"
"Man, he has a pretty girlfriend. I think I remember my wife was pretty like that when I...." Oops!

That was 10psi then 14 psi, well out of the "sweet zone" of this turbo. I was doing everything short launching from a dig...40 MPH 2d gear launchs, 3rd gear WOT, 4th gear WOT until triple digits+, 1st gear launchs from about 3K.

We were running through a series of other peoples "base maps" other turbos "base maps" and basically just testing. The reason for this session was a small issue with a SX fuel regulator's return line being blocked at install, so he was running at FULL pressure when he did the initial tuning. Just running back through some maps to make sure we weren't LEANED out.

THEN, the boost gets turned up to 16.5 psi. By this time, I was just "impressed" with the single, but not really motivated to drop my pants and write a check. So I was pretty "Ho-hum" about the additional boost.

SHHHHHEEEEEEETTTT! First time I hit the gas in 3rd gear the rear end of the car just SQUATed and went! I slow back down and do it again, because I don't believe the BUTT DYNO telling me there is a huge change. Put it in 3rd, get to about 3000RPMS, hit the LOUD pedal. SHHHHEEETTTTTT! The rear tires spoke back for a second, the rear hunkered down, and the car shifted time zones.

It is amazing how much difference there is between 14 and 16.5psi. Going from 10-14psi was "okay" but this change was a mind bender.

Amazing! So now the questions revolve around

"How much?"
"How soon?"
"How quick?"
"How much furniture do I have to buy the wife so she won't notice the new turbo?"
"Heck, can I trade the wife in on the turbo?"

 

Now, there are two more singles that I am going to be involved in tuning here, in the next week. Both are T78s. I am willing to bet after helping these guys with cars, I am going to be a HOPELESS convert. Let's see what happens.

 

Just to add my $.02....

I was taken for a 16 psi test/tune flight in the same vehicle. The only additional comment I would add to Badog's is...........

HOOOOOOLY SHHHHHEEEEEEEEEEEET!!!!!!

Anyone wanna buy a kidney, slightly used?

 

Badog, YOU DA MAN, I'm first in line for tuning . I need it bad.

 

go get yourself a bung and get in line!

 

i assume they are speaking of your car kyle? let me know wassup ...

 

you all are hilarious...kidneys and wifes up for sale...lol

Perhaps renting the wife out would be the way to go...I know it would take longer but at least you would get to keep her.

post pics!

hahaha...

sounds like a blast...am anxious to get my m2 gt30's in their range as well...am only boosting 12lbs prim and 14sec right now...should have the car tuned on the WB by the end of tomorrow for a flat 16lbs. cant friggen wait. you guys got me all excited.

have fun boys


j

 

So was the boost coming on hard and planting you in the seat at around 3K or what? How soon is the boost hitting? If your cruising and just plant your foot did you have to wait on the boost or did it take off right away

STEPHEN

 

Stephen,

We figured out the simplest way to compare boost onset/curves. Take a video of the tach., speedo, and boost gauge. Oh, and the audio of "HOLLLYYYY SHEEEETTTTT" helps a little bit.

I did a couple 3rd gear throttle drops at 3k, 4K, 5K, 6K. The sensation of the wait is quickly erased when the boost is up. When "comparing" performance with this gentleman, side-by-side, mano et mano, he pulled about 4-5 cars by 130mph+, from 40mph in 2nd gear. And I was at 14psi to boot!

Higher the revs when you boot it, the farther back into the Bose Acoustic Mess system you get pressed into. Thats right, into the trunk!

One way to take care of the wrinkles in your face...have your skin pulled away from your face by G forces!

I don't know how many G's we are talking about here, but its alot more than my car!

Steve/BuckeyeAuto: okay, 3 T78s to tune!!!

 

Was this with the GT35 @ 16.5PSI?

 

The real question is how bad am I going to beat all of you.

Jason

 

Yes.

 

Let's tune you up first, Jason! Stay tuned to a NEW sage from the infamous BUTT DYNO when Jason's T78 manages to get tuned!

Key disclaimer: No dead animals were harmed, no reasonable laws were broken, all hardware was purchased and installed via Rx-7 Store.

 

Ok now are you comparing the GT35/40 at 16.5 psi against your car with stock twins at 14psi??? If thats the case I could see pulling 4-5 cars from 40-130 with a 2.5psi difference in boost. Maybe I'm confused. What 2 cars were you comparing? Was everything else besides the turbo the same like porting and all that?

STEPHEN

 

Just make sure that old man next door to you, doesn't beat you up first

Scott

Peace

 

If you don't start behaving, there is going to be no WB for you ...

K

 

sounds like it worked out for you?

 

Only difference was the turbos. Same mods, same porting.

But you have to remember 14psi on the twin and 14psi on a single are still very different CFMs. When we were at 14's, he pulled over 2 cars on me.

Scott, the state hospital is on alert for Jason's neighbor. So is the ER, in case he has a heart condition.

 

Hmm, I dont know seems like alot of money and work to gain 2 car's. Thats what I was getting at, I realize the larger turbos flow more cfm, however it sounds like it wasnt flowing that much more.....i mean eventhough the twins are small, there are 2 of them. If I were going to go thru all that I would want to get more than 2 cars from 40-130mph. Two cars in the 1/4 is only worth about .3ish. I'd imagine if he pulled 2 cars from 40-130 it would be even less gain thru the 1/4.

I wonder how the stock twins would do up against it if both were running 16psi so that the single is in its sweet spot. Of course AnthonyNYC ran 11.1 with not much more than 16psi on stock twins.

Sounds like it spools pretty well though so I'd imagine if someone was going to go single it would be a good option.

STEPHEN

 

you need to compare the SAME cars before and after the single turbo conversion.. ill bet his single turbo setup is not even tuned yet either

 

Poweraxel - It is my car that Badog is talking about. My engine/twins have never been as strong as his, before the single conversion, I had to run 2psi more than him to keep up ... even though we had the same mods and were running nearly the same map.

BTW: If my memory serves me I saw Badog from my inside rearview mirror during our pull that started at 60 and he let off about 130. I'm going to call it 4 - 6 cars from 60 - 130.

Comparison of my car with twins v/s GT35/40: from a 40 roll my car never "squatted" like it does now, nor was I able to overcome Badog by any cars, yet 4 - 6!

The GT35/40 outspools the stock twins at any rpm over about 3.5k (ie we punch it at the same time, I spool and take off before he does with the stock twins) and feels sooo smooth w/out that "lag" in power around 4.5k (no transition). It just keeps pulling harder and harder and harder - gawd, I never want to shift!!!

As for tuning I've only done AFR tuning with the OZ-DIY (still in the upper 10's lowest 11's, very safe - less power). Have not done any timing tuning yet. My map does advance timing a bit after peak torque, but am still running a "safe" 12 degree split from N10 - N20 & P14 - P20.

K

 

jesus i want a single so bad.

luigi

 

Yup. I was a doubter...a hater...a non-believer. But have your driven a car with a GT35/40?

Just save me the bandwidth and don't do it. You'll be happier living with the twins. I know I would have been happy with my twins.

IF only I hadn't driven his single. Will my twins ever forgive me?

The difference has to be felt to be appreciated.

 

Badog, let us know how that tuned T-78 feels compared to the GT setup. I am going with either these two turbo`s very soon and would like a real world comparison not just a dyno graph. Are You guys going to push the boost up a bit so We can see what they pull like at say 18 PSI? I bet there will be a big difference at 20 PSI.

 

I'll be dyno'ing on Oct 11th or 12th and if I get a 3bar map sensor in and working properly I'll probably try 18psi, not sure about 20psi on an (original) stock motor 40k miles. If my new ported motor arrives from Pineapple by then and is sitting in the garage I may try 20psi...

With a stock ported motor, twins v/s GT35/40 you loose almost nothing at the bottom end, the twins maybe spool 400 - 500 rpm earlier, but you have great gains with the GT35/40 over the rest of the power band since you have the ability to raise the boost safely (for the turbo) way beyond the twins.

Soon we will make a video of GT35/40 boost gauge & tach v/s twins boost gauge & tach v/s T78 boost gauge & tach.

Thinking out loud, a 2k punch, 3k punch, 4k punch, 5k punch in 2nd, 3rd, 4th. Watching this video should answer everyone's spool questions... Might be tricky to find a road we can safely attempt a 4 or 5k, 4th gear punch though, the rest we definately be included!

K