Hi,

I am looking at designing a twin turbo kit for an LT1, and am just trying to make sure about the routing order of the different components.

My assumption:

1: Air filter
2: Turbo
3: BOV
4: Intercooler
5: Air Temp Sensor
6: MAF
7: Throttle body

The problem I have is whether this would be the correct placement for the MAF, or if you are unable to run the MAF and have to instead go to a Speed Density setup. Is this why people often change to a Delphi or FAST setup? I will be doing a lot more research on this over the next couple of months, but I am just trying to get the layout correct in my mind.

Thanks a lot,
Jon

 

You can run a MAF if you want but with a good aftermarket EFI system and a wideband you can tune the system in speed density just fine and not have to deal with a restriction in the air inlet.

I would think a MAF sensor would work more accurately before the compressor since it's actually measuring all of the air going into the engine as it goes in, vs while in a compressed state.

With the IAT on the boosted side it's going to kill timing since it's reading hot air. I would think letting it sample ambient temperatures would be favorable. Mine is in the throttle body elbow though just so I can test the efficiency of my intercooler.

 

The MAF before the turbo would probably be a problem if I ran a twin turbo setup, right? I would have to run both intakes through the same sensor...Or could a person run two of them like resistors in paralel? Probably not. Just thinking out loud here. Another posibility would probably be to have a bored out one that you have programmed into the computer.

Why am I obsessed with trying to run the stock computer? Cost for one, and the challenge. Perhaps I am just a glutton for punishment.

Any other insane people with input?

Jon

 

Not that Brandy is insane.

 

Lots of people have relocated the MAF to the pressure side of the system. I think it would only be a matter of tuning the PCM to take the compression of the air and temp into account. As far as the IAT goes, it's there to read the temp of the air entering the engine, so the PCM can make the proper calculations for the air/fuel ratio. Again it's something that can be tuned in the PCM.

 

That was kind of what I was figuring, especially with wanting to know the IAT for figuring fuel curves and such.

I guess my thinking is right, then, from the first post...Or, should I say that it is not wrong?

Jon

 

It is actually better to have the MAF after the compressor, close to the throttle body, because that is the actual air being used by the motor, so that is the air you want to tune for, not the much cooler air before the compressor, when the air after the compressor will be much higher, look at the design of most supercharger/Turbocharger kits on the market, the all usually leave the MAF on the pressure side of the compressor, by relocating it to the inlet side of compressor, you will be able to tune easier, but not as accurately, as with most turbo kits, even the innercooled ones, the IAT is much higher than ambient, making a huge difference. You want to measure the air in it's "compressed state" as that is the way the motor is getting it, and why you bought the power adder, but that's just the safe way to tune it. We have designed Turbo/Supercharger kits, in the past present and future, and have all of our MAF's on the pressure side. any ?'s ask, or inquiries about future or current kits, feel free to call.


current kits available:
4.3 liter s-series Turbo and Supercharger kits

In development:
2.2 liter s-series turbo kits
LS1 Turbo kit
4.8/5.3/6.0 liter fullsize GM truck turbo kit
3.8 liter F-body supercharger kit
5.9 Jeep cherokee turbo kit

Mach Performance
586-468-6300

 

Ya know...there is a reason all the Supra's in the 9's are faster, are single turbo'd. 1 really nice turbo will beat 2 smaller ones anyday. But look at the benefits already...Only have to buy 1 turbo, only 1 turbo manifold, only 1 of pretty much everything from the air filter to the block.

 

Won't two smaller turbos spool quicker?

Jon

 

There's much more space in a Supra engine bay, than there is in an LT1. Two smaller turbos are probably easier to place than a single larger turbo.

 

Yes but they will run out faster....2 larger turbo's will take forever to get moving but your have an awesome *** top end. If someone must do a twin turbo, figure out the size turbo you'd want. Say you want 2 t3/t4's. Now get 1-2 turbo sizes smaller and 1-2 turbo sizes bigger. That way the smaller one will spool faster and once it gets into the higher rpms the larger one will take over so you can continue to shine. You'd have 1 BADASS powerband. Hell, you could even do a t3/t4 and a t60.

Those little t3/t4's are no joke, they good for like 450hp or something near that which is perfect because that is right when the t60 would kick in and they good for 800hp or so....It's kinda like having a single turbo kit and a small shot. Something just to get the big turbo to spool a little faster and the smaller one will really make the larger one shine.

 

Yea, but it's not just figuring out where to put 2 turbochargers. It's where to put the 2 of everything needed from the air filter to the block. Unless for some reason your running the 2 smaller turbo's in tandom to compensate as 1 bigger turbo. Don't know how well that would work but if that's what your doing, I'd really like to sell some pictures and know how it's going.

 

toykilla,

Thanks for the input. I guess I really hadn't thought about doing the single turbo because of the difficulty of routing both exhaust to the one turbo. Perhaps that may yet be the easier route to take. BTW, it would be for my friend's 78 camaro. I will wait to do mine until after his is finished.

Jon

 

BOV doesn't go to intercoolers inlet. It goes to the outlet. List should be somewhat like this...

1. Air Filter
2. Turbo
3. Intercooler
4. BOV
5. Air Temp Sensor
6. MAF
7. Throttle Body

I don't really know which order the MAF and ATS should go because I don't know how they go stock. I would put them on the same way you took them off.

 

A 5.7l shouldn't have any problem spooling up a turbo. Checkout Brady's site www.turbocharged.net