Latest Winter Project: TWINS!!!!!

After much debate with many friends of mine, I am going to build a twin turbo kit for my car. I am going to use the engine in my sig (95 bottom end, stock rotating assy 80k miles), limit myself to 8lbs of boost and keep it a daily driver (not that it will be one, I just want the ability).

First I should mention that I know nothing about turbo's, A/R's or any of that crap. I have friends for that, some that are making BIG power and awesome streetability (one had a 2Jz swapped MK3 Supra and the other guy has a 98 V6 stang with a GT35r and a split port swap).

The turbo's that have been selected for me a are 2 brand new Mitsubishi 20g's internally gated (getting them both for 100 bucks). From what I have read these will support 430-480 on a EVO @ 22lbs. Since I have twice the engine I want 2 and will be limiting myself to 8lbs, so I think I should be ok. I am going to be using a 31"x12"x3" FMIC with 3" cold side pipe.

Here is my questions:
Will 42# injectors be enough at boost?
Can I use a rising rate boost referenced regulator to handle raising fuel pressure?
Will a single 255LPH be enough pump?
Will a 70mm MAF in a blow through configuration be enough with out pegging the meter? Or should I get a C&L with the 42# sample tubes?
What size BOV should I use? And should I use a recirc style instead of atmospheric to make the MAF happy?

I am sorry for all the newb quesitons, but I just don't know.
Also at 8lbs (reason I chose that number was I have alot of head work done to these heads and they flow damn well and since boost is nothing more then restriction through an engine, I thought that would be safe) what numbers do you think I will be making?

Thanks!!
 
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How much power do you want? I am building a TT kit slowly with Turbocoupe turbos, and many other people have done the same making close to 500 hp at the wheels. Enough to split your block in half. Check out millhouse on here he had a thread a while ago that had alot of information. Pretty sure he was around 485hp at the wheels..
 
Here is my questions:
Will 42# injectors be enough at boost?
Can I use a rising rate boost referenced regulator to handle raising fuel pressure?
Will a single 255LPH be enough pump?
Will a 70mm MAF in a blow through configuration be enough with out pegging the meter? Or should I get a C&L with the 42# sample tubes?
What size BOV should I use? And should I use a recirc style instead of atmospheric to make the MAF happy?

I'm no turbo subject matter expert but am a far cry from a stranger to boost. So here goes:


Boost referenced regulator - Would not be my first pick. Let the tune and the injectors do the walking, not some fuel pressure weirdness. Take a look at the Kenne Bell Boost-A-Pump. It will regulate/condition power going to your fuel pump and effective allow a 255lph fuel pump to run in the neighborhood of 320lph WITHOUT having to try and resort to elevated fuel pressures. On that note.... using regulators and/or FMUs that cause variations in fuel pressure CAN be problematic to tune in some circumstances.

Fuel Pump - A good Walbro 255L will be fine.

MAF - A 70mm will be plenty but the physical size of the meter has absolutely NOTHING to do with whether the meter, "pegs" or not. The sensor in the meter determines that. If it were me, I would not use a blow-through setup if I could avoid it. Either way, look to a PMAS or SCT meter. I wouldn't give you a plug nickel for a C&L meter or housing. Juss sayin'.

Injectors - 42lb is plenty and will allow for a lot more boost than just 8 lbs.

BOV - Never used one and wouldn't recommend a brand. They sound kewl though. :D That's the only advantage to using it over a bypass, that I'm aware of.
 
RC and this other site have some decent calculators for your injectors.

RC Fuel Injection

Injector Size Calculator

The recirculation of the blow off valve is not necessary. Companys like HP use an atmospheric vent and do not seem to have the idle, surging issues many imports tend to experience. Yes, there will be a split second rich condition (as air vents), but there is less backpressure as the air escapes. The whole idea is to vent the reversing air charge (as it bounces off the throttle blade) before it slams back into the turbo. The size will depend on the amount of boost and location you place it. If I remember right, to large and you will experience a bit of lag as you put your foot back into it. To small, it will be unable to vent quickly enough. I'm no expert, but have seen the simple bosch style (off of DSMs) used for 12-14lbs, around 500 horses and function adequately on a single V8 turbo.
 
I'm no turbo subject matter expert but am a far cry from a stranger to boost. So here goes:


Boost referenced regulator - Would not be my first pick. Let the tune and the injectors do the walking, not some fuel pressure weirdness. Take a look at the Kenne Bell Boost-A-Pump. It will regulate/condition power going to your fuel pump and effective allow a 255lph fuel pump to run in the neighborhood of 320lph WITHOUT having to try and resort to elevated fuel pressures. On that note.... using regulators and/or FMUs that cause variations in fuel pressure CAN be problematic to tune in some circumstances.

Fuel Pump - A good Walbro 255L will be fine.

MAF - A 70mm will be plenty but the physical size of the meter has absolutely NOTHING to do with whether the meter, "pegs" or not. The sensor in the meter determines that. If it were me, I would not use a blow-through setup if I could avoid it. Either way, look to a PMAS or SCT meter. I wouldn't give you a plug nickel for a C&L meter or housing. Juss sayin'.

Injectors - 42lb is plenty and will allow for a lot more boost than just 8 lbs.

BOV - Never used one and wouldn't recommend a brand. They sound kewl though. :D That's the only advantage to using it over a bypass, that I'm aware of.

My 70mm 94-95 Maf meter is pegged at 5k with no boost... It's not gonna work for boost..

And yes it is the size of the tube that matters. You can take that sensor out and use it in a 3.5 inch tube if you have access to your Maf transfer.. I am going to be running a slot style Maf sensor in my car from pretty much any ford 05+.. they use the same sensor in all the new cars. Just depends on what motor and size of air intake to determine Maf transfer.
 
My 70mm 94-95 Maf meter is pegged at 5k with no boost... It's not gonna work for boost..

And yes it is the size of the tube that matters. You can take that sensor out and use it in a 3.5 inch tube if you have access to your Maf transfer.. I am going to be running a slot style Maf sensor in my car from pretty much any ford 05+.. they use the same sensor in all the new cars. Just depends on what motor and size of air intake to determine Maf transfer.


Your MAF transfer tables are meaningless as soon as you put that sensor into a different housing. Well... that is unless you have a meter flow bench machine. :rolleyes:
 
Your MAF transfer tables are meaningless as soon as you put that sensor into a different housing. Well... that is unless you have a meter flow bench machine. :rolleyes:

i have a maf transfer calculator that gets the numbers close then you just need to put the car on a dyno and hold it at your set voltages and move the kg/hr around till you get the result you are looking for. no need for a flow bench.. this is my current maf transfer from a 94-95 70mm housing and sensor. yes you are right the maf transfer tables are meaningless if you put the sensor in a new housing...like i said they will have to be modified but you can use the sensor in a bigger housing.


volts kg/hr
16.000 924.638
5.000 924.638
4.750 802.215
4.500 692.211
4.250 593.867
4.000 506.169
3.800 443.309
3.600 386.280
3.400 334.320
3.200 288.443
3.000 247.128
2.800 209.869
2.600 176.918
2.399 148.023
2.200 122.677
2.100 111.271
2.000 100.625
1.900 90.487
1.800 81.362
1.600 64.633
1.500 57.536
1.300 44.610
1.200 39.034
1.000 29.148
.750 19.770
.600 15.208
.400 10.392
.000 8.871
.000 8.871
.000 8.871
 
The problem that you may run into jeep, is that those sensors are tailored to the housings that they came in. By that I mean, they are electrically and mechanically designed to flow within that housing. I know what you're getting at but the problem is that your sensor will usually (not always) scale well inside of a housing that it was not designed to be in. The result is a varying degree of success/failure. Some folks get lucky while other spend months chasing gremlins. Kind of like with a C&L.

C&L's answer to the problem was to try and use sample tubes. I think most are aware of the hit or miss success with that system. What their solution offers that yours doesn't however, is the potential to retain a higher degree of resolution at lower air volumes.

Either way, it's definitely not a solution that I'd go to for car I was planning on boosting --and-- keep street manners. It's simple to tune a meter for WOT runs. Very contrary for constantly varying CFM and turbulence pattern.
 
Well I know a bunch of people that have used this method without drivability issues. The guy that is helping me tune my car has used this method for alot of his customers without any issues.. Im not saying that the average Joe could do this easily but it can be done without problems.
 
I wish you luck with it. Really I do. Something that may of help though... If you get to a point where you're seeing inconsistant results, try changing around the inlet tract or reclocking the meter housing. Sometimes it smooths things out. One other thing to keep in mind with ANY aftermarket housing is that there's usually a significant difference in how the meter acts on the dyno vs. how it acts on the road with that air being turned every which way by the movement of the vehicle. So once again, before you throw your hands up swearing up a storm, try changing the air-flow up the meter if you find things going screwy.


Good Luck! :nice:
 
I wish you luck with it. Really I do. Something that may of help though... If you get to a point where you're seeing inconsistant results, try changing around the inlet tract or reclocking the meter housing. Sometimes it smooths things out. One other thing to keep in mind with ANY aftermarket housing is that there's usually a significant difference in how the meter acts on the dyno vs. how it acts on the road with that air being turned every which way by the movement of the vehicle. So once again, before you throw your hands up swearing up a storm, try changing the air-flow up the meter if you find things going screwy.


Good Luck! :nice:

Thanks.. So far my car has been tuned over the Internet and phone via datalogs. Which I didn't think was possible till I did it. So far I have gained 32 hp and 20 tq over stock tune but like I said earlier the Maf is pegged at 5k.. I have heard horror stories about dyno tuning for wot.. Then the drivability is horrible.. The guy I am working with has been very good at keeping drivability good. It might even be better than stock.. I know the idle is much better than it was... Thanks for the encouragement.
 
I will be using the stock airbox with 1 straight tube, 1 90 degree transition to the tb and 1 straight transition to the airbox to eliminate as much funky turbulence as possible. Pretty much just like stock but bigger..I am using the slot style Maf because it will be in the middle of the tube, where the stock one would be out by the edge. Being in the middle should be better for repeatability is what I am thinking.
 
I am also going to use the Slot style MAF. My buddy that has the turbo V6 98 stang is using one. When we test fired it on the stock tune and 42lb injectors, it ran fairly well. Now he is in the mid 400's power wise with awesome driveability.

Now for tuners, I am going to use my A9L, should i get a quarter horse or something like an SCT chip. It will be dyno tuned.
 
I would personally get the quarterhorse and a innovate lc-1 wideband..and if you want get it dyno tuned. Or you can go the route I went and have it tuned over the phone and Internet. www.eectuning.org, there are people there that can help you. Decipha is who has been helping me out.. Great guy and he will not stop till it's perfect..
 
I'm not as smart as jeepguy so my recommendation (for simplicity sake) would be an Anderson PMS. The most recent version (4, I think) allows the input of a mass air transfer function (previous versions didn't). The nice thing about the PMS vs. tuners like TwEECer, MOATES, and Quarterhorse is that, so long as you have a wideband, you can sit there and add/remove fuel while you're driving down the road from an interface that looks something like a Gameboy.

I used to have a TwEECer R/T and what a POS/PITA that was. In fairness, I've not tried the Quarterhorse or MOATES but I understand that the tuning methods are similar to that of the TwEECer but are better supported and a bit more reliable.
 
I'm not as smart as jeepguy so my recommendation (for simplicity sake) would be an Anderson PMS. The most recent version (4, I think) allows the input of a mass air transfer function (previous versions didn't). The nice thing about the PMS vs. tuners like TwEECer, MOATES, and Quarterhorse is that, so long as you have a wideband, you can sit there and add/remove fuel while you're driving down the road from an interface that looks something like a Gameboy.

I used to have a TwEECer R/T and what a POS/PITA that was. In fairness, I've not tried the Quarterhorse or MOATES but I understand that the tuning methods are similar to that of the TwEECer but are better supported and a bit more reliable.

Yes for simplicity sake the PMS will be easier but also more expensive. The quarterhorse is realtime tuning also.changes can be made while the car is running. I bought my quarterhorse in December with no clue about the way the EEC worked. That's why I paid someone 100$ to tune it for me. I have spent hours on the phone just asking questions and trying to understand how everything works. It looks very complicated but it's not that bad once you get the basics down. I am the kind of person that likes to know how and why things work. So I bought a book written by greg banish called engine management advanced tuning. Good book, very informative and it makes it easier to understand the how's and why's of the EEC. So if you are willing to take the plunge buy this book. Even if you get the PMS I would recommend it. I don't know much about the PMS so I am not gonna say anything about that. I think for all the stuff I needed to get tuning it was 6-700$ quarterhorse,Lc-1(eBay it's cheaper) binary editor, EEC analyzer( helps you by analyzing your datalogs and giving you suggestions. Not needed though) and someone to help me get started.