Twin Turbo LT-1

[Guest Anonymous]

Ok yall have got me convinced that a 350tt would be a very do-able project, i'm not talking about for my Z(for now) but i have a 1970 Nova drag car(only runs low 14's) that i have been fooling around with, my question is dose anyone know anythin about TT on an LT-1? i guessed it would be cheapest o build(plenty of them in wrecked cars and they are F.I., i think they have a VSS(vechicle speed sensor) and i belive this might cause a problem, but maybe they are MAF sensors, i think i could run theis setup easily seeing as the car s not street legal and overheating and such wont be a probmlem thanks in advance Justin

[Guest super280z]

thought about it, it seems like a good setup but a heads and cammed LT-1 is in the neighbor hood of 400-450 depending on the combo maybe more, but twins are big MONEY. ask BLKMGK what a set costs the LT-1 is definately a good start but i'd explore all the options before jumping right into a twin setup. very enticing still.

[Guest Justin]

Well, I am far from an expert but I don't see how the VSS sensor would cause any problem with a turbo setup. I have a buddy who's going to be running 18lbs of boost by way of D-1 through a 383 LT1, and I believe he did mention something about the MAF... I think that if it reads an airflow value over a certain amount it trips a code... But you need to spend a lot of money to get to that point and still have all your con rods north of the oil pan.

[jeromio]

As far as codes, MAF and EFI tuning goes, there's a company called Carputing that sells a software and cable package called LT1 Edit. It runs about $500. You use it with a PC and you can change pretty much any and all variables. Very cool. You can optimize for any condition and remap fuel/air ratios.

[Owen]

Not an LT1 but could provide useful info nonetheless. http://www.skulte.com/turbo.html

 

Owen

[Guest Anonymous]

Heres a link for a couple ECM editors:

 

Lt1 Edit: http://www.lt1.net/editor/

 

TunerCat: http://www.tunercat.com/tnr_desc/do_tc.html

 

As far as MAF (Mass Air Flow), thats correct it does report the amount of air flow and then adjust its fuel maps accordingly.

A MAP (Manifold Absolute Pressure) has predetermined fuel maps that it uses, while basing the tuning on throttle position and other factors. (I hope I said that right, this is all from research I've done on the two systems).

 

If a Stock MAF ECM can handle some boost and adjust things accordingly, then it would definitely be the system of my choice. I'm looking to find info on using the MAF system with turbo's. There is some restriction through a MAF and big flow MAF's are expensive, but even with the restriction I think the turbo(s) would make up for it.

 

Regards,

 

Lone

[BLKMGK]

I like MAFs myself, instead of inferring airflow they actually measure it. However when running boost you'll end up reading the MAP sensor too I'd think. Suggest you check out the LT1Edit folks and pick their brains or those of their customers - I'm pretty sure they have a WEBBoard too. MAF sensors for GM are pretty much only available through Granatelli who has an exclusive with Pro-M. I think Bob Atwood just died though so no telling what will occur now

 

MAFs have a definate range. Flow more air than they can measure and you max them out - hitting the top of their voltage range. At that point you DO set a code - Mustangs flash the check engine light too. There's bound to be ways around that though either with a bigger MAF (?) or with programming. The Procharged LT1 guys ought to be able to help. Worse comes to worse switch it to a MAP setup or custom computer. Not sure how easily an OEM MAP sensed system is programmed - not with LT1Edit I'm pretty sure. You'd be at someone else's mercy most likely

[Brad-ManQ45]

My understanding is that even w/LT1 Edit, the stock computer doesn't read boost - you have to kludge other values.

 

I too, would like to use the stock system, but won't until boost is capable of being read.

 

BTW, Compression is alittle high on the LT1 (cam too big to?). I going to run more than 6 lbs boost, would probably want to replace rods.

 

I've been researching this for a long time - I like the reverse cooling aspect for turboing.....

 

Brad

[Guest Justin]

Just FYI, the 93 and older LT1's are MAP. From my understanding, MAP setups aren't as "forgiving" to less than ideal fuel maps as MAF cars are, but generally put out more power in stock or near-stock form.

 

As for the LT1-edit software, I actually toyed around with it a little bit on my 94 Z28, definately some trick stuff... if you have a bunch of buddies with LT1's, you could split the cost of it up between you... I think between the wiring harness, software, yadda yadda it runs about $300 or so... but it's only $50 to add another VIN number (e.g. another car)... Also, the LT1 edit software does let you switch an MAF motor to MAP. If you choose to go that route.

 

Personally, on MAF cars I think you'd reach the point where you'd need to switch to bigger injectors (and hence reprogram for that) before you'd reach the point where you'd have to retune the fuel maps.