| GT30R, GT3037S,
GT35/40R and GT3071R, which one will it be? |
Is it just a matter of HP? Do
I want 400HP? 500HP? or 600HP? Want answers? We can help!
We'll break it down for you so you know what to expect! By
plotting out some actual data (that we've collected) on how
each turbo responds specifically on the EVO8 engine combination,
you can draw you own conclusion!
|
|
Some
background on the above turbochargers:
The GT30R, GT3037S,
GT35/40R and GT3071R
are exceptional dual ball bearing turbochargers built by Garrett
to cover a wide range of engine sizes and power ranges.
GT30R - A very popular name
for a SERIES of Garrett ball bearing turbos, ranging from
350 HP all the way to 650 HP. Commonly mislabled as ONE particular
turbo, but in fact there many wheel combinations built by
Garrett referred to as "GT30R's". Many turbo selection errors
have been made in the industry as a result of the wideness
of the HP range in the GT30R family, ie. larger wheel combinations
used in smaller engine (lower HP applications) resulting in
poor spoolup. GT30Rs' are part of Garrett's earlier ball bearing
line-up (consisting of about a dozen different wheel combinations)
and are still very popular and reliable turbochargers, but
because of its history of "misuse" and improper application
matching and its lack of single identity, can no longer be
used as the "benchmark" for comparison.
GT3037S
- A particular variant of the GT30R family, but more commonly,
another one of Garrett's ball bearing turbos found in a certain
Japanese tuning company's turbo kit, popular for producing
up to 500 HP. Commonly referred to as "the GT30R."
GT35/40R - aka
the GT35R. On the larger end of the small frame ball bearing
family. Quickly becoming the favorite for 600 HP high revving
4 cylinder engines. The GT35/40R goes where older and bigger
turbos such as T61's and T64's (bigger, bulkier, slower spooling)
would have gone, except the GT35/40R's quick spooling characteristics
make these 600HP setups more streetable.
GT3071R
- A brand new ball bearing turbocharger recently created by
Garrett engineers to help fill the gap between smaller 300
HP turbos and the laggy GT3037S. The GT3071R is also one of
the Garrett engineers' favorites because of its superior wheel
match (between the compressor and the turbine wheel). A better
wheel match means higher levels of efficiency. Higher levels
of efficiency mean the turbo works less and achieves more
and is happier and makes more power reliably. This is quickly
becoming one of OUR favorites as well.
|
| Our
findings:
The GT3037S - This "benchmark" turbo, used by the popular
Japanese kitmaker, was the first to find its way into our
prototype kit. We were very impressed with the power, but
was not impressed with the way the "500 HP" turbo spooled
up on the EVO8 engine. We quickly pulled up dyno charts
of the same turbo installed on the EVO8 engine via other
popular kits utilizing tubular manifolds and found that
those setups spooled up yet another 300-400 rpm later. We
deemed this combination unacceptable for the average EVO
driver.
Since the GT3037S represents
one of the newer and more preferable variants of the GT30R
family, we decided to skip the rest of the line entirely
for EVO8 testing.
Then came along...
The GT3071R - A brand
new "450 HP" ball bearing turbo introduced by the Garrett
engineers partly to solve our EVO8 dilemna. Wham! It was
right at home! The unit complimented the EVO8 engine well
and performed to expectations. Boost was seen 700 - 1000
rpm earlier than the GT3037S and only 200-300 later than
stock. With some tuning and larger injectors, we managed
375 WHP on modest boost: achieving our goal of a setup that
makes 450 crank HP, spools close to stock and does not require
swapping out everything under the sun, ie. FMIC, cams, headwork,
etc. To get the power, all you you need is a nice free-flowing
3" exhaust as we have installed on our test car.
GT35/40R = 600HP? Definitely
doable. We initially ran the kit using Garrett's turbine
housing, but found the A/R to be too aggressive for street
use on the EVO8 2.0L. We've massaged our own turbine housing
to scale down the A/R and have managed to get the GT35/40R
to spool up as quick as the GT3037S spools on other off
the shelf kits. 400+ WHP was quickly seen on low boost and
660cc injectors on an otherwise stock engine. |
Our
Stage III turbo kit for the EVO8 (aka "Stealth kit")
After months of testing and development with the EVO8 engine
combination, we have devised an upgrade system that is both
elegant and simplistic while accepting no compromises in power
potential or reliability. With POWER and RELIABILITY being
the two key criteria for the development of the EVO8 turbo
upgrade kit, we set out to test every possible hardware combination
available. In our kit, you will find a system that integrates
a plethora of unique but well designed components that compliment
each other to achieve those two things that you care about
most. In addition, in an attempt to exceed the customers'
expections we have added other features such as a "direct-bolt-up"
housing that overcomes the "reverse-rotation" issue, v-band
downpipe discharge, bolt-up oil/coolant kits, etc. in order
to make the installation process as simple as possible. All
this while retaining the appearance of a completely stock
engine bay.
The kit hardware will consist of the following:
- Garrett Prototype GT Ball Bearing turbo w/ATP Proprietary
Housing with GT inspired High-Flowing Valute
- Bolt-in design retains stock manifold - Retains stock
heatshield for OEM appearance
- Steel braided lines and fittings for oil/coolant connections
- Tial 38mm External Wastegate
- Stainless wastegate discharge tube with downpipe re-route
- Silicone connectors and clamps
- All mounting hardware, gaskets and CNC machined fittings
- 450 crank HP utilizing the ultra efficient GT3071R
- 3.0" Stainless steel downpipe w/stainless O2 housing
- 100% bolt-on design. No welding, cutting, or fabrication
GT3071R w/.63 A/R kit price:
$2399
Note (as
of 06/21/04): By
popular request from our customers, the intercooler discharge
pipes and silicone couplers are now included in the EVO8
kit to insure a true bolt on system.
Other turbo options available for customers that insist:
GT3037S w/ .63 A/R
- No additional cost - GT3037S
spool up dyno chart
GT3037S
w/ .82 A/R - No additional cost
GT35/40R
w/ .63 A/R - $350 extra -
GT35/40
spool up dyno chart
GT35/40R
w/ .82 A/R - $350 extra
|
 |
