GT35R turbo for 3.4L? - Page 3

Tippy · 12-02-2011, 08:28 AM

I am dying to hear the outcome.

For reference Forte, I have a 3.4L Carrera with factory Motronic.

I too only get full boost (1-bar) in 1st gear at nearly 5500RPM, 4500 in 2nd, and <4000 for 3rd and 4th (T-4 flanged Turbonetic T60-1/0.81 A/R IIRC).

Since you have a G-50 as my Carrera has, a 3.4L motor EFI, T-4 flanged, and going to a Garrett, it is nearly apples to apples comparison between our cars.

Please report back as soon as you can!

BTW, I've hit as high as 447whp. 427whp dyno sheet on hand. Hopefully will get to dyno soon as my friend offered to pay. This time with really cold temps instead of ~70 degrees when the others were done. Maybe I'll break through the 450whp mark?

forte500 · 12-04-2011, 04:59 PM

Tippy, and (others) who contributed to my orig post - I am getting the car back this week. I had the GT35R installed and .8bar spring put in. Check out the dyno on youtube (Frank Forte GT35R 930 turbo - YouTube). Putting out 460RWHP at .8Bar and full boost by 4000 RPM. Tuner says is spins the wheels in 1st and 2nd no problem. The motor was built to handle higher boost but I prob won't go higher than 1BAR and my tuner is very conservative (which I actually prefer)..lol

I'll report on my first test drive this week - I can't wait.

Tippy · 12-04-2011, 08:41 PM

Did you go twin-scroll?

You said full boost at 4000 RPM. What gear?

If you did that in 1st with a G-50, we have a winner. If it is 4th, that is about where I am at now. And like you, I want mine to make boost in 1st at a decent RPM, not full boost at 5500 RPM where I have to shift in a split-second banging the rev-limiter every time.

911TT33 · 12-04-2011, 08:57 PM

Quote:

Originally Posted by forte500

Tippy, and (others) who contributed to my orig post - I am getting the car back this week. I had the GT35R installed and .8bar spring put in. Check out the dyno on youtube (Frank Forte GT35R 930 turbo - YouTube). Putting out 460RWHP at .8Bar and full boost by 4000 RPM. Tuner says is spins the wheels in 1st and 2nd no problem. The motor was built to handle higher boost but I prob won't go higher than 1BAR and my tuner is very conservative (which I actually prefer)..lol

I'll report on my first test drive this week - I can't wait.

Told you you'd be happy with the 35R

There isn't enough load on the engine in 1st to create full boost earlier with a single turbo that's capable of flowing 650hp. If you want even quicker spool, go for a smaller GT3071R turbo (less top end power), or a pair of small twins on shorty headers.

JBurer · 12-06-2011, 06:40 AM

Frank - that's a pretty healthy result from .8Bar!

Do you have a cat on the car? Sounds nice!

Quote:

Originally Posted by forte500

Tippy, and (others) who contributed to my orig post - I am getting the car back this week. I had the GT35R installed and .8bar spring put in. Check out the dyno on youtube (Frank Forte GT35R 930 turbo - YouTube). Putting out 460RWHP at .8Bar and full boost by 4000 RPM. Tuner says is spins the wheels in 1st and 2nd no problem. The motor was built to handle higher boost but I prob won't go higher than 1BAR and my tuner is very conservative (which I actually prefer)..lol

I'll report on my first test drive this week - I can't wait.

Tippy · 12-06-2011, 10:13 AM

I'm like a lion staring down a zebra right now...............I wanna know if you went twin-scroll and what gear you make full boost @ 4000 RPM?!?!

forte500 · 12-07-2011, 04:22 PM

I did not go twin-scroll....I pick up the car on Sat mor and will be sure to offer a detailed report and/or will road-test to answer any specific questions. Spoke with tuner today and asked "more" questions...he was clear that the car hit full boost in 1st gear by 3100 (not 4000 rpm) and broke the tires free easily throughout...in 2nd and 3rd full boost by 2900...Frankly, I don't believe it but he said the "car is just amazing" and responded better than they ever thought - said "it feels like the pedal is connected to the turbo".

I tried to talk him into (like it 's his car..lol) putting at 1.1 BAR spring in NOW - but he felt that a better option would be to put a variable digital boost controller in that steps up boost in each gear (.8 in 1st and 2nd; 1 in 3rd; 1.2 in 4th and so on). Thought it would put less stress on the drive train and get more control. I like this idea - for the next spring $$$$

911TT33 · 12-07-2011, 05:01 PM

Agree, an EBC is the best option for accurate boost regulation. Just don't get TOO TEMPTED

Tippy · 05:31 PM

HOLY SHI'ITE! Full boost in a G-50 in 1st gear by 3100 RPM? That's amazing!!!!

That is 2400 RPM sooner than mine. Very impressive.

If you back up what the tuner claims, that'll prove how superior the newest Garrett's are and ball bearing technology.

TurboKraft · 12-08-2011, 09:07 AM

Told you that was a good turbocharger for your engine. :-)

Quote:

Originally Posted by forte500

I tried to talk him into (like it 's his car..lol) putting at 1.1 BAR spring in NOW - but he felt that a better option would be to put a variable digital boost controller in that steps up boost in each gear (.8 in 1st and 2nd; 1 in 3rd; 1.2 in 4th and so on). Thought it would put less stress on the drive train and get more control. I like this idea - for the next spring $$$$

This is a built-in function on the Motec M600. I can't recall if the M48 can do this.

911TT33 · 09:28 PM

Quote:

Originally Posted by forte500

but he felt that a better option would be to put a variable digital boost controller in that steps up boost in each gear (.8 in 1st and 2nd; 1 in 3rd; 1.2 in 4th and so on). Thought it would put less stress on the drive train and get more control. I like this idea - for the next spring $$$$

The APEXI AVC-R EBC allows you to set different boost levels for each gear

Just an option if your Motec ECU can't

forte500 · 12-10-2011, 10:55 AM

Just drove the car back from tuners (Dawe Motorsports).....AMAZING and freghtening power and torque throughout the RPM range. Full boost in 1st Gear between 3000-4000 RPM ..hard to look down as the rear end was ALL over the place, 2nd Grear saw .8BAR around 3000RPM and rear end began to sway, 3rd Gear a quick wiggle around 3000 and then a missle-like linear pull to redline.....awesome. On-ramps felt like a pinball when the plunger first launches the ball..lol

The tuner said this was the fastest single turbo-car they ever built and were surprised by the perf of the ball bearing (GT35). Guys - I am only at .8BAR and despite my initial protests for 1+BAR, I couldn't image needing anymore power (did I just say that?). Beyond my driving capabilities at this point.

As described - the turbo feels connected to your gas pedal. Linear but still the infamous single turbo kick-in-the-pants feel. Have to say Chris (TurboKraft) told me this from the start, but I was a skeptic. Engineer by schooling, I questioned the step-function improvement gains people described. Sorry Chris...and ..James (who finally talked me into it)....at least I didn't learn the hard way and go with the KKK!

PS. there were 2 people or 400lbs of smiles during my driving "exibition"

forte500 · 12-10-2011, 10:59 AM

One more thing - I was advised to NOT get the anti-surge option with the GT35....in fact, mine came with it and I swapped it out to the conventional intake. Anti-surge could compromise a few hundred RPM of response and I didn't want any question. No surging at all with this motor, and I suspect most of these engines.

911TT33 · 12-10-2011, 02:20 PM

Sweet! Good to hear you're loving the new setup

Seriously, go to 1bar and utilize the compressor efficiency of that bad boy! I ran mine at 1.25bar for years and it was just an animal! Killed everything on the road in outright acceleration... It was brutal

forte500 · 12-10-2011, 03:38 PM

Come the spring, I will probably put in a variable boost controller and/or control with Motec. I would like to increase the boost a little bit in each gear and maintain reliability on the engine and drive train. I can't imagine many sports cars having the acceleration this has....it just keeps pulling hard til redline. Great recommendation!

Tippy · 12-10-2011, 04:17 PM

Aw man, I'm so jealous! The boost response sounds unbelievable!

If it were a 930 box, the boost onset would be even sooner in 1st. Insane.....

TurboKraft · 12-12-2011, 09:12 AM

Quote:

Originally Posted by forte500

One more thing - I was advised to NOT get the anti-surge option with the GT35....in fact, mine came with it and I swapped it out to the conventional intake. Anti-surge could compromise a few hundred RPM of response and I didn't want any question. No surging at all with this motor, and I suspect most of these engines.

Frank, the need for the anti-surge compressor cover depends on the engine specs.
A build yours -- more displacement & compression, head preparation, large tube headers -- usually does not need the anti-surge.
A more basic engine can more easily experience surge and need that version of the compressor cover.

rodolf · 09:20 AM

With GT40 (a/r .89), GT2 cams and 3.4l, i've got full boost at 3000rpm in 3th gear.

Only 150/200rpm later than with my old GT35 and 964 cams

forte500 · 12-12-2011, 01:22 PM

Took the car out again on Sunday.....WOW, it can't believe the acceleration. I am getting better at anticipating the wheel spin and learning to control the launch.

On a hard downshift from 4th to 3rd, on highway, I noticed what felt like a momentary "ignition-kill" (RPM/boost dropped as if shut off) and then back to normal and didn't do it again. Motec showed no flags (RPM limit and/or MAP limits well under limits). This happened once before and during tuning - Tuner put in hotter plugs, and checked the voltages and connections at the coil-packs. Some tweaks were done, but the "Ghost" reappeared yesterday. Seems like something minor or in the programming.

Anyone have any clues?

911TT33 · 12-12-2011, 01:51 PM

I had to run a Crane HI-6 ignition system on mine because the boost would cause ignition breakdown under load, however, that was at 1.25bar... Unlikely that's your problem at only 0.8bar