BT build expectation thread

[rfinkle2]

I'd like to gather some info so guys upgrading turbos can have a resource on what to expect from particular fuels in different areas of the country.

I.E. Without decent quality pump gas, you are going to need e85 to run > 20-22 psi. In terms of balancing boost vs. VVT and ignition advance, this could mean taxing the stock fuel system to the point you will need to budget for either a 6th port or meth injection kit.

I do understand that there are some areas of the country that have very good 93 octane and can utilize a BT for big gains, but those areas are the monority, imo.

Everyone's experiences and opinions appreciated.

[Hammology]

I think this may be common knowledge, but in case someone was unaware. So Cal, and probably california in general has shitty 91. You will need a 5th/6th port, meth kit, or a healthy dose of corn to make the kind of power your going to want out of a BT.

[manila]

@rfinkle2; Thanks for making this thread. Hopefully it will help me decide, which turbo I am going to go with

[rfinkle2]

Even if this thread turns into the best brands of gasoline to use in different areas of the country, that would be good info as well. I can say in the NJ / PA area, Sunoco and BP are hands down the best, with Shell being terrible.

[mr.speedy3]

In AZ, I stick to Shell, Valero and QuikTrip.

Mainly Valero (because their my E85 distributor) and Quicktrip though. I've never had an issue with their gas. I've had 2 tanks of bad gas from Shell.

[Hammology]

The most consistent gas in my area IMO is cheveron, but it's still 91 so that's not saying much. The best fail safe for a bad tank of gas is meth or a few gallons of E85.

[JgamB]

I was getting 14* advance at 6K RPM with no/minimal knock on Chevron 93 in Bama. I've switched to Mapco because they have teh magic corn, although their 93 would've forced me to pull 1* of advance.

I will be joining the slew of mid-turbo BNR S3 V2s upgrades as soon as they are available, so I will update how far Justin can take me on 25% Eth and 100% IDCs. I'm trying to avoid meth so I can't go full retard.

[levon.mark]

Alaska sucks

[Chimmike]

I'd say count on using either e85 or methanol.
Don't get yourself into a corner with a daily driver that you have to find e85 stations wherever you go for the e85 mix.

If you have a ton of e85 stations around you, great!

If not, you should definitely consider methanol. Not as supplemental fueling but more so for BAT control/anti knock properties.

IF you're not planning on building a motor, you really don't need 6th port. You also don't need a turbo like a 3076 or larger. 3071s, precision 5858's, and others are perfectly capable of making great useable power on a stock block without being laggy.

If you find 350whp is just not enough for you, or 400whp is not enough for you, start saving for a built motor and 6th port, do the right supporting mods, and it'll all pay off in the end.

[Hammology]

5858>3076

[shane5747]

Southwest PA here:

As most already know, a GT3076R is a large turbo for the stock fuel system. I am only a few revisions in to the tune, but I am already seeing the stock fuel system being taxed heavily. Don't expect to use this turbo to it's potential unless you have aux fueling.

As for gas quality in Southwest PA, I haven't had luck with anything so far on the BT without the use of e85 to keep KR away. I've gone through Sheetz, BP, and Sunoco for 93, but it wasn't until I added a gallon of e85 that I was able to see a reduction in KR. (Could be my car, but I'm posting my results)

So far in my opinion, on the stock fuel system + e85, the GT3076R is almost useless at this point. I am making around the same power as a 3071, with much more lag. I expected this though, but the price for it was something I didn't want to pass up (Got it very cheap). I would stick with a smaller frame turbo, or expect to add aux fueling.

Listen to @gingermike; he pretty much has it on point.

[Tomas]

Rob,

You need to be a lil more specific as to what you expect of your car.
Do you want fast spool and usable torque down low Or big numbers at the price of lame response and off boost performance?

If you run a manifold with equal length runners that are longer than about 8" linearly, a 38mm WG and a turbine housing with at leasst 0.83 A/R you can probably run more than 22 psi to red line on 91 octane and 12-14 degress of timing past 6K.

If you are going for a build and are willing to compromise off boost performance for power you can decrease the compression ratio to 8.5 and will probably be able to run 25 psi or more to red line on 91 provided same thing as mentioned above about manifold construction. The drawback is off bost performance will suffer for it. You'll probably be running close to 4 HG IM pressure going down the highway at 80 mph instead of the usual 10 HG or so. The engine will also be less rev happy which many concider a bit on the lame side. Fuel consumption will also go up.

You can run low octane fuels and still make power. The design of the system as a whole just needs to be able to compensate for it by being better. Separation of pulse charges and smoth transitions in the EM, low backpressure at the turbine housing and a large enough WG all make for a less knock prone system as does lowering the compression ratio.

In other words, bad fuel in one part of the country can still get you more power than good fuel in another part if the set up is better. There are a lot of variable to take into consideration when you compare one car to another running different fuels.

[rfinkle2]

Originally Posted by Tomas Rob, You need to be a lil more specific as to what you expect of your car. Do you want fast spool and usable torque down low Or big numbers at the price of lame response and off boost performance? If you run a manifold with equal length runners that are longer than about 8" linearly, a 38mm WG and a turbine housing with at leasst 0.83 A/R you can probably run more than 22 psi to red line on 91 octane and 12-14 degress of timing past 6K. If you are going for a build and are willing to compromise off boost performance for power you can decrease the compression ratio to 8.5 and will probably be able to run 25 psi or more to red line on 91 provided same thing as mentioned above about manifold construction. The drawback is off bost performance will suffer for it. You'll probably be running close to 4 HG IM pressure going down the highway at 80 mph instead of the usual 10 HG or so. The engine will also be less rev happy which many concider a bit on the lame side. Fuel consumption will also go up. You can run low octane fuels and still make power. The design of the system as a whole just needs to be able to compensate for it by being better. Separation of pulse charges and smoth transitions in the EM, low backpressure at the turbine housing and a large enough WG all make for a less knock prone system as does lowering the compression ratio. In other words, bad fuel in one part of the country can still get you more power than good fuel in another part if the set up is better. There are a lot of variable to take into consideration when you compare one car to another running different fuels.

I guess I was speaking to what is currently mass produced and widely available and leaving the nitty gritty out in terms of flange design, runner lengths and compression ratios.

I think I may have created a shitty thread honestly, but my intention was not to disappoint anyone thinking of upgrading turbos, it was moreso an effort to stress that dropping in a turbo upgrade doesn't necessarily mean monster numbers, especially if running a mazda hotside and / or currently available manifolds.

e.g. Most guys are utilizing either atp drop ins or bnr's which have similar characteristics due to their use of the atp and mazda hotside.

I'm glad to see you posting more again Tomas. Your expertise and opinion is always appreciated.

[mituc]

Originally Posted by rfinkle2 I think I may have created a shitty thread honestly, but my intention was not to disappoint anyone thinking of upgrading turbos, it was moreso an effort to stress that dropping in a turbo upgrade doesn't necessarily mean monster numbers, especially if running a mazda hotside and / or currently available manifolds.

No, I don't think you created a shitty thread (I'm actually glad you opened it). Everybody needs to be aware that past some air flow values the heat (and lack of knock resistance) can bring power down a lot more than the added air flow increase it.
And with the stockish setups (motor, turbo flanges, ex-mani) the only possible way of fighting heat and knock past to the little a larger intake and a FMIC can do is to put more pressure on the stock fuel system which will bring even more limitation to the entire equation.

Maybe now you feel that this thread turned into something else, but when it comes to "expectations" we can discuss particular setups and analyze their ability to either not generate that much heat or push heat away through the exhaust or other heat exchangers the car has (intercoolers, radiators, other custom air ducting to cool various parts of the engine or the engine itself, and so on).

Of course, heat/cooling and knock resistance+fueling are only some of the aspects that need to be looked into when people add larger turbos to their cars. I'm pretty sure we will have members with a lot more capable setups from this point of view (fueling, air flow and heat dissipation) and weaker from others (engine strength, transmission, mounts, fluids, chassis rigidity, and so on) which we will have to advice to stop before they exceed some threshold.

[Easter Bunny]

Originally Posted by Tomas Rob, You need to be a lil more specific as to what you expect of your car. Do you want fast spool and usable torque down low Or big numbers at the price of lame response and off boost performance? If you run a manifold with equal length runners that are longer than about 8" linearly, a 38mm WG and a turbine housing with at leasst 0.83 A/R you can probably run more than 22 psi to red line on 91 octane and 12-14 degress of timing past 6K. If you are going for a build and are willing to compromise off boost performance for power you can decrease the compression ratio to 8.5 and will probably be able to run 25 psi or more to red line on 91 provided same thing as mentioned above about manifold construction. The drawback is off bost performance will suffer for it. You'll probably be running close to 4 HG IM pressure going down the highway at 80 mph instead of the usual 10 HG or so. The engine will also be less rev happy which many concider a bit on the lame side. Fuel consumption will also go up. You can run low octane fuels and still make power. The design of the system as a whole just needs to be able to compensate for it by being better. Separation of pulse charges and smoth transitions in the EM, low backpressure at the turbine housing and a large enough WG all make for a less knock prone system as does lowering the compression ratio. In other words, bad fuel in one part of the country can still get you more power than good fuel in another part if the set up is better. There are a lot of variable to take into consideration when you compare one car to another running different fuels.

Very informative. But I am severely disappointed in the lack of gay inuendos and penis references.

[Jester2552]

If anyone finds themselves getting around Idaho I would bank on just 91 at a Chevron. Boise has like 2-3 E85 stinker stations I believe and probably around the same for 93. But other than that you'll be extremely hard pressed to find anything better than 91.

[Boost_creep]

I think it's a great thread, Rob. But I didn't see your experience listed. LOL. I think we should set some guidelines, like relevant data, to see what people are experiencing.
Here's mine:

GTX3071R
TMIC
Valero 93 octane
Can safely run 21 psi, with a max of 11* of timing
Afr around 11:1, with idc's below 100%
This has netted me roughly 340whp

[Smelson]

GT2871R
Cobb FMIC
Custom exhaust manifold
Full 3" exhaust no cats
3.5" intake
~100% IDC in 40* weather
11*@22psi
Shell 93
West Virginia/Virginia/DC

I had a tuner ask if I had head work done and other people ask what was wrong with their car. It's all about flow mods, my engine is completely stock.





Sent from my SAMSUNG-SGH-I337 using Tapatalk

[mituc]

GTX3071R, 100% stock block/head/IM/EM
Tiny whiny Cobb SRI intake, SU TMIC
gas: OMV Super 100 (similar with 94OCT)
24PSI and about 12.5 degrees of timing at redline
Afr around 10.5:1, with IDCs around 100% (99-102%) from about 6100rpm up;
350whp (VD CF1.01.) around 5850rpm, above 340whp from 5500rpm to rev limit (6700 on that map).

Now with the latest map @Lex put together for me I should be above 340whp from 5200 to 6700rpm and peak to about 355whp at 5900-6100rpm (maybe 360, I don't really care now with this long ass flat power curve above 5k), still making 330whp at 6950rpm which still makes me think revving to 7krpm makes some sense when I want to ride the 3rd or 4th gear a bit more (running slightly more load, 0.7AFR leaner AFRs, about one more degree of timing above 6000rpm).
However, because I'm on pump gas with no aux fueling the ambient temp needs to be below like 10C/50F to be able to benefit from all the timing with no interference from the "high BAT no knock" table.

[taf0422]

Turbo: BNR S3
Supporting: Built motor, stock head, ported intake manifold, Meth 75/25, E85, 3.5" intake, exhaust manifold, full catless exhaust.
Gas: Shell 93 with shell e85
Boost/Timing: 26psi with 16 degrees
AFR : 12ish (been awhile) IDC's in mid 70's
Power: 424/397

Dyno Graph

[snailD]

Salt Lake City, UT

Gas: Shell 91
Turbo: GTX2867r
Boost: 21 PSI
Timing: 9 degrees at 6k / 11.5 at redline
AFR: 11.8 tapering to 11.1 at redline
IDC: 85% at 70 degrees

shell and chevron have the most consistent gasoline in the salt lake area and are about the same. i just like shell and had a good station right across the street but i'd recommend either place.