Im buying the manifolds, and putting the fuel system together to mock up my TT set-up on my 305 before I start building the motor set-up to be turbo.

I was considering buying a used LT1 intake, harness and pcm for this. But I was reading on what has to be done to convert and its kinda a pain. A Holley Stealth Ram would be much easier and price would be similar as I already have a TPI computer and Harness.

Would there be a big difference in power output or powerband depending on which I used? I was under the inperssion they put up similar numbers in silimar areas.

 

Ram tuning isn't as big of an issue in FI engines as in NA ones, as i'm sure you already know. But from what i gather it does help to an extent. Most of the high-hp turbo buicks (1000+hp stage 2 engines) tend to use a tunnel ram style intake with runners upwards of 12 or so inches long and fairly large plenums.

GMHTP had an article with a NA built TPI engined 3rd gen that made a switch from a modified factory intake to the Holley Stealth Ram and picked up some incredible power. Improved 5-6 tenths in the quarter.

Found the article:
http://www.gmhightechperformance.com...holleystealth/

In my opinion it would be better than the LTx intakes since it supposedly directs the air better. HTHs

 

Cool well I asked because I had converted my TPI to carb, and have to move back to fuel injection to make turbo tuning easier, and to get it the fuel it needs. I was just wondering which would be better. The biggest thing I was thinking was easier tuning and computer programing. As my car was already TPi before and I still have the ecm and all, it would obviously be easier to bolt on the HSR.

For fuel and air levels I'll most likely just use an AVCR (I think thats what they are called) But I guess the PROM chip in the stock TPI ECM would still need ot be burnt custom for a TT set-up.

 

Check out the new ROMulator from tunercat, it replaces your burned chip in the PCM with a flashable EEPROM that can be programmed in real time as the car is running, the whole deal (chip and tunercat software) is in the $150 range I believe. Check out www.tunercat.com for details. This is an outstanding option to burning chips!

Bill

 

Sounds like a plan, what turbos you have in mind to use? I'll go ahead and warn you, you might want to take SMOKNZ's suggestion on the tunercat. With a front-pull intake manifold the rear cylinders will have a tendency to run leaner than the front... and when you get knock it's mostly from the rear cylinders. So you might want to set the duty cycles on the rear injectors a few percentage points higher to compensate.

The factory intake the turbo buicks have use a plenum on top of what resembles a ram style intake to help give more even distribution, but the rear cylinders still tend to run a little leaner than the fronts...

Factory intake:
http://www.gnttype.org/techarea/pict...rbointake.html

Here's a stage 2 intake:
http://www.gnttype.org/techarea/pict...stomstage.html

The intakes we use tend to make this lean tendency worse. HTHs

 

I went into the site, I couldnt find anything about a ROMulator? What is it under on the side menu?

As for Turbos Im building the engine, and me and my friend collectively are going to be putting the turbo system together. Hes bigtime into DSMs so hes more qualified with the air/fuel system than I am, as well as turbos. I think he said he wanted to use Garret TO4Es or something like that? Because they are bigenough to hold boost all teh way through my RPM band with a large displacement motor, and they are fairly affordable.

 

What kind of displacement are you going to use?

 

Click on the RT tuner (RT=Real time) and you should find some info about it.

Bill

 

I dont post here much but this thread got my attention.

if your gona go turbo and your swaping back to EFI. your best bet is to swap to a 7749 ecm.(sy/ty ecm) If you have a 7730 or 165 harness you can Just repin to use a 7749.

The ROmulator from TunerCat is nice. but you still need a burner.
The romulator 170ish and a burner 100-150ish is what A new device from Craig will cost. Which is a ALL IN ONE device, Turning your ecm in to a tunable on the fly setup.

depending how soon you plan to get into tuning check out Craigs site here http://moates.net/index.html and look into the AUTO PROM. check out the diyprom board on thirdgen.org there is alot more info over there on his creation.

Im in the middle of building a 412sbc with twin turbos for my 91vert myself. feel free to e-mail me if you need anymore help.


Chris@cecoatings.com
www.cecoatings.com
Ceramic,Powder and Thermal Coatings

 

I know that you think it would be easier to go back to efi, but blowing through a carb is very easy now. Vortech and procharger both make boost referanced fuel pressure regs, they add 1psi of fuel pressure for every 1pound of boost, thats how they get thier superchargers to work on carbs. Im sorry, I do have freinds that like mustangs, They showed me in this months issue, they have a ford fairlane goin 9.4 at 130mph and 15pounds of boost on a stock short block, mild cam, world product heads and a 600cfm holly carb. The turbo is huge, but he doesnt even use an intercooler!! The only carb mods he did was jet extensions and solid floats, (stock floats crush under boost). I dont no the name of the mag, I think its mustangs and fast fords or something like that. The cam was spec was like 488 lift! If they can do that with a ford, Imagine what you can do!!!!

 

I know you can do it though a carb, but tuning is infinetely easier with a computer and fuel injection set-up. No pissing with float levels or anything, just set your fuel and air levels in your ECM with a programmer.

Thanks for all the info guys Ill get through it all eventually, I havent had teh chance to get into it much yet since this is exam week. Ill go out and see which ECM I have too, I dont know the numbers off the top of my head.

As for displacement, I have a 400 block around now that I was gonna use, and go 406. However I dont think the thin walls of the 400 can take much boost. I was gonna swap over to a 010 high nicke/high tin 350 4 bolt and go 383. Unless you guys think that the 400 can take 14-20 lbs of boost on an 8:1 engine.

 

GOD!!! I love turbo talk! Always learning something new Got a couple of "new" T-netics racegates for sale in the classifieds if anyone is interested

 

I'm not up to speed on the 3rd gen stuff (learning as I go ), but I always thought the computer on the TPI cars did not like boost at all. The TT IROC I worked on is having all kinds of problems with this. It's getting DFI this winter to solve the problem once and for all.

 

If its all customed programmed with a programmer it shouldnt matter. I wouldnt think it would anyway.

 

There's always DFI.