I got through the first 2 chapters but I got some Homework so I'll try to read another chapter tommorow. Its amazing at how much info is packed in here, I think this a very good $40 sepnt on some insurence before anyone starts a project like this to get the book and read it :yesnod:

 

agreed, my only beef, is that the main reason i got this book was in hopes of some really good design layouts and options. i need more information pertaining to the late model GM fuel injector sensors regarding boosted applications. all the diagrams in maximum boost show the MAF inthe filter side of the turbo, and i know that this would be near impossible with a twin setup. i read somewhere that a stock MAF can be used on the charged side of the intake setup if the calibration tube inside is changed, but there is still very limited information about this and i would like to find some more so if you run across anything like this please let me know! the 2 or 3 bar MAP sensor i found easily, and the boost referencing fuel trim is nicely covered, seems that the stock ECM of the LT1 is actually a not bad for turbo tuning if it is programmed accordingly, but a boost referencing timine control may still be needed on top of the stock computer. and fuel pump upgrade is pretty obvious even bfore the book, but always nice to find some equations to calculate and really apply to your custom setup! well, so it begins.. this should be a very fun ahd challenging project with some very nice rewards at the end!

Chris

 

Wow, one night out drinking with the ladies and I miss all the good questions you guys have for me :yesnod: Well, here it goes
Light84vette: I've been told by trubonetics that with the turbos I've chosen I should be able to put atleast 15psi on a 396ci engine. So that equates out to 700HP with no intercooler and over 800 with one. Not to shabby for my only car 9 months out of the year. :D

lcvette: That'd be cool, my cell number is 507-269-6354, feel free to call after 8 CST(that's when my free minutes kick in :lol: ) That offer is open to anyone that would like to chat about this stuff. :cheers:

Red91VetteI am running a twin turbo setup, but only half of it is done, that's why there's only one turbo. It makes for some interesting turbo Fizix questions and behaviors. I'm running the Garret 60-1 HIFI with at .84 TO4B turbine housing. This was the largest compressor wheel I could fit in the smaller size housing, and it should be plenty. Since the project is still in progress there is no intercooler and since there is only one turbo, no wastegate as of yet. I had the header custom designed and made to fit. My welder worked with an aeromotive engineer to help design some good airflow through it and amazingly enough it looks similar to the callaway TT header. The problem with the stock manifolds is that the outlet is way to far forward to do anything with and there is no extra room to pipe it elsewhere. You've got to think about where you want your intake piping to run, I'm sneaking mine between my steering column and the header, it's going to be very close, but should work. I'm hoping to have the intake piping soon, but the parts haven't come in yet. The airfilter is going to be a pain to fit on there due to the crossmember about 5 inches infront of the turbo, but I think it'll fit with some help :smash: I'm a little afraid of picking up some kind of water or something driving in the rain or through a puddle with the airfilter on the bottom like that, but I don't see any alternatives right now. There are some good things and bad things about mounting the turbos low, you've got to decide how you want to do it. My one big criteria for doing this project was that it had to be FULLY bolt-on. And so far it is. I'm spent about $3500 for everything so far, about $500 of that were mistakes, oh, um, learning experiences :D and I figure it'll cost about $1500-2000 to do the other side.

Ok, my fingers are tired now. I hope I answered all the questions, if not let me know.

 

So I couldn't use the stock exhaust manifolds or block huggers? I was just going to do that and have a small 90*bend and run that into the turbo, and icvette had a good idea to put the air liters where the battery went and the washr fluid tank if we could fab up some kind of scoops. So that won't work? There isn't enough room to use a modified header with the turbos facing towards the front of the car? I was thinking about buying the custom header plate, I saw it in the summit mag and its a plate that bolts on to your heads and has a 1 5/8 tube sticking out about 2", I could get the custom header kits and somehow weld up my own, I never welded before, and I bet a welder is pretty damn expensive, so im gonna have to pay someone to do it, but I gotta get my car on a lift and see what kind of room I am working with down here. I want to do this TT setup soo bad! What kind of motor do you have? how is it built? I was thinking of a 355/383/396 comletely forged out, is the stock block ok or woud I have to get the dart block? I don't know what comp ratio to run, 9:1? Also what cam? I was thinking of the TPIS 409X cam? With AFR 190or 210 heads, and a mini ram. Well I will always have more questions, until im comletely finished with my car, thanks for putting up with all this. I just have to find a daily driver car first so the vette can be down for a while. Thanks for all the help, im going out now to buy that book, hopefully I will finally understand how the turbo and wastgate stuff works.

 

Thanks mn_vette you really cleared up some questions everyone had.

But Icvette I dont really understand the part of the MAF and the MAP sensors, I;m not sure my 84 has any of those even though its EFI its a 2bbl TBI. So I dont see it having any of those. Also If I use a STEALTH RAM which has its own computer, will I have to worry about any of the MAF or MAP contraptions?

Also Icvette I read the Chapter 17 and the equation he uses to get the size needed for a Turbocharged engine is weird. Here it is From page 203 " The suggested value is 6 square inches of flow area per 100bhp. Assuming a desired BHP of 375,

375 BHP X 6in(squared)/100BHP=23in^2.

Using the guidelines driscussed in Chapter 5... 23in^2 of low area, but 46 is needed because half is air tubes...So a core with a depth of 3 inches will need to be 15inches wide.

WHAT ABOUT hieght? if its 15x3 then that 45 which nearly meets the requirement, but is going to be only 1inch tall? So if it was 5x5x2 then that will meet the demand to? Thats kinda small, what about 18inches wide and 12inches tall and 3 inches thick, then that can support 5400HP? I'm confused about this section, could you please take a look at page 203 and see the equation and tell me if you can get better sense out of it, because I'm lost here. :confused:

 

i think you overanalized it a bit, lets look at it from a cubic approach... he says a 3" depth and 15" width equalling 45 sq/in, we are looking for surface area on a 2 dimensional plane, with the core being of standard thickness. i think he left out some information thats pretty important, but what i gather from this is if we are looking for 600 bhp, divide 6/100= .06 sq/in and then multiply by our bhp goal and get 36 sq/in, then we account for the air tubes by doubling the original surface are and get 72 sq/in. so we find one large core in any length (or depth as he uses the term) by any width whos product is closest to 72 sq/in.. ie..

11" x 7" would yield a surface area of 77 sq/in which exceeds our requirement. keep in mind that this is the core size, not the entire intercooler which might have up to an additional 2" of tank on each side making the overall size 7" x 15" plus the tubing for connecting the duct work may even extend the overall length by an additional 4" making a 7" wide intercooler x 19" from tip to tip. this is how i interperetted the information in his book, but i still feel he could have opffered some more information here! going with twins would mean two rather small intercooler cores of sizes in the 6" x 6" range or 3" x 12" how ever you decide to get to 36 sq/in per intercooler. go figure, we will figure this out somehow! :D

Chris

 

Then I dont think that the intercooler and mounting it would be too much of a problem then. But what about the MAF and the MAP sensors you were talking about? Do they play that much of a role? Are those parts present in an Aftermarket EFI system like the StealthRam? Also I hear a whistle when Turbocharged cars are under hard throttle and they let go, a little whistle lets out that sounds pretty cool, are those Blow off vavles? BOV, where could I get them and how much do they cost, and how do they know when to open? :confused:

 

The MAP and the MAF are ways for the computer to read how much air you are stuffing into the engine.
I dont know a thing about the 84 and that freaky FI. I will look into it later in my corvette book.

lcvette,

Gm's prototype twin turbo cars had 2 MAFS on them. I think I have 1 other pic on my computer somewhere.


Also, i think some of the first callaways used a single MAF on the back of the air filter, which ran to a piece of sealed frame rail, which went to each turbo. I am not 100% sure on this, but it looks like that is what Reeves Callaway is saying on the sledgehammer video about a standard early model TT vette.

But as you know, a single MAF can only get you so much HP before it is the bottle neck.




[Modified by bill mcdonald, 12:31 AM 2/26/2003]

 

Yes, the MAF and/or MAP are critical parts for any fuel injection, (I dont know about mechanical FI) these measure how much air is going into the motor.
Maf meter air flowing through it.
MAP measure the pressure that is in the plenum.

Your 84 Has a MAP sensor too, I just looked it up. I have only seen one other TBI system, it was on a truck and it was using a MAP sensor as well.
DFI uses a MAP, FAST uses a MAP, I think all of them use a MAP but OE stuff.

 

I agree with this for the most part. There are a couple of cars on this forum that make 700hp with a MAF. Some of the Callaway guys Ive talked to say the MAF cars run better(tuning wise) than the speed denisity, but I dont have any first hand experience to back that up.

 

Cant we just use two MAP sensors and splice the wires together to make it work? Instead of having just one?

Also do you know where I could get a engine control program that will control the engines fuel injection, spark and boost? How much do they usually go for? Like the DFI units? :confused:

 

mn_vette, Where did you get your turbos, wastegates, exhaust manifolds etc? I pricing up everything right now, and looking to start my projet soon. Im looking to run a 383 twin turbo set up. I was thinking about getting a richmond 6 speed, with a built up dana 44. I am thinking about running a world block, with a forged rotating assembly, 8.75:1 comp. brodix heads, and the big roller tpis cam, I forget which cam it was. Im not sure about what intake to run,a miniram, or a fuel injected carb manifold with one of those 90* bends on it with a big throttle body. I am going to try and run the turbo and wastegates under the car, I know space is very limited down there, but what is the biggest turbo I can fit own there? I want the most HP possible with the limited space restriction. Also would block hugger headers with the turbo mounted to the bottom of them be good enough for over 700hp? There isnt a place around here that could do custom headers for me. Thanks.

 

Turbonetics have thier smallest Turbos rated at 465HP each, so thats way more than 700, it will exceed you goal by 200+HP. ANyway I dont think a Richmond 6 speed will handle anything near that power, arnt they only rated at 450ftlbs of tq? Also if you could, I would buy a Viper Transmission, many owners are running 1000HP on the stock Transmissions. They cost about 2500 but I'm not sure if it will fir into a C4 or not? :confused:

 

The engine sounds good, I will be getting all of my future turbos from http://www.cheapturbo.com they should be able to hook you up. I had turbonetics do a thing for me and they said for a 396ci engine with 15psi I would need the 60-1 compressors and that would give me about 700hp no intercooler, 800 with. so I would try for the 60-1 HIFI compressor wheel, definately do the HIFI version, smaller housing with only slightly diminished airflow. still capable of 700hp easy. they will run about $725 each. The wastegate I got from ebay, about $200 each, you might want to go with a Racegate to be safe, but it'll cost a little more. As for your headers, block huggers still have the outlet in the middle similar to the stock ones, right??? the big thing is you need the turbo flange to be past the rear most exhaust port on the head. This means custom header. Once you get the turbo pull the exhaust and try and fit it in there. and you'll see what I'm talking about. Make sure to leave room for the airfilter too. I got my header made out of mild steel for the first pass through, besides I couldn't find anybody that worked with stainless. I talked to a local welder and he did it for me, I ordered the parts from http://www.headersbyed.com they have bolt plates and u/j bends that you would need to do it. I just dropped my car off in his back lot, pulled the stock header and jacked up the car so he had a working reference as to where things had to be to clear everything. The parts cost about $250 and labor was around $5-600 at $45/hr. When designing the header remember air velocity is the key to a turbo system. and also make sure that you know where you are putting the piping to go to the intake from the turbo, you might have to design the header around that too. Good luck, the fun part begins once you start ordering parts. Good luck! if you've got any questions, we're all here to help. :cheers: :cheers: :cheers:

 

oh boy... two MAFS? i am now very curious how this will be to tune and what other adjustments would be needed to achieve accurate use with two MAFS..perhaps the two could have their voltage sum sent to the ECM for its calculations, but how would this be achieved, and how would the MAFS be wired in? i would really like to figure this out for the late ,model LT1 guys who don't have the SD systems. also, is there any way to use the MAF between the throttle body and the intercooler? would the pressure affect/damage the sensor or maybe cause some kind of false signal? i think that pressurized air would be tricky to measure as opposed to an air charge a 1 BAR, not sure how the MAF would work in these conditions, anyone else heard of anyhting? let me know, i am busy researching and gathering parts, have a rearend to put back in the fiances 95 LT1 Vette, and once i get her car back on the road (since i broke it) i will get my beloved 96 CE LT4 back to pull in to the Bay and start the ductwork and engine modifications to pack the twin setup in it... can't wait. i spoke with Ed Wright and we are going to investigate some ideas to use the stock ecm and perhaps turn off the MAF, and focus tuning it as a speed density system, but we are of similar mind that the car may need to be present for this feat to get a solid base tune on the dyno, and fine tune it from there to have a marketable tune for a complete TT LT1 setup. i will keep ya posted on the progress, but it may be a while before anything actually materializes, it is hard to find the time to make a trip to Oklahoma, and trailering a vette all the way there from NC is not exactly something i am overly anxious to do, but if it comes to that with no other option then so be it, i will have to take one for the team..lol :cheers: well, any input for the gander will certainly be appreciated, this is becoming a very indepth project research so far, but it is very interesting to say the least!

Chris

 

WOW------this is a great discussion.I have many opinions on this subject.

First---if you go with a single turbo set-up with a 60 series--you will not want the .63 precision housing-the .82 housing will be better-the .63 will BLOW the tires away----any lag will help with wheel spin-and pull pull like a mad-man on the top end!!!!!!!!!!!!!I am giving experiences from my GN --taking one housing off and puting on another.I don't want to get in the middle of a discussion-besides saying-----------take your serious questions to http://www.turbobuick.com --if you want-i am a registered member-and i will----but i think some of these "ideas" are a bit off----------just trying to help---------love the idea of a couple of turbos on a vette----(you know i do -----"my GOOD BUDDY"!!!!!!

please keep this discussion going--very good.

Geoff

 

Wow, I had no idea this post would get this far and that many people be seriously into it. My only problem is getting a custom pair of headers. There isn't a shop around here that could do it. I am going to get that book soon, it finally came into the book store(I had to order it). Once I figure out my header problem, everything shouldn't be too difficult, except affording it all :lol: . I am going to run a DFI system so I shouldn't have any problems with that. ghall, that is exactly what I want, to blow the tires away! The only problem I see with that is trying to find a trans and rear end to hold all that power, I want a 6 speed trans, but I'll end up going with a 4L80E, and rear end, I don't know if a built up dana44 can take that, might have to do a custom 9inch rear instead. As far as turbo lag goes, im keeping my nitrous kit for that.

 

lcvette,

Since you are talking to Ed Wright, what about some programming for a stock LT1 computer so that we could swap in a 3 bar MAP sensor and use speed density and manifold pressure, maybe steel some fuel tables from the GM Cyclone and convert them over to the LT1 setup??? Just something I've been thinking about, and if he needs it, I'd be happy to drive my car down there to do some experimental stuff for him, pull the FMU when I got there and swap in the sensor and a new chip.

 

Ghall,
which ideas are off, let me know if i am on the wrong path, the book i have is absolutely like a boost bible! it ROCKS!!

turbo booooooost! :D :D :D :D :D :D :D :D


MN_vette,
i will speak with ed this week again if i can get some of his time, he is a BUSY man! and 9 out of 10 times unless i get him on the phone his "assistants" are unable to go as indepth on the tuning with me as he can so when i have the time and he has the time i will certainly try and get some answers for you! although, there is nothing free about my business relationship with him..lol all work we do is stillpaid for. :smash: lol but i will keep you in mind for when i get the time to go maybe we could link up in OK!

back to the books for me!

Chris

 

Well, I guess it would all depend on how much it would cost. After the turbo system I've only got one leg and 1 1/2 arms left. :lol: But I'd really like to know if he could do the thing with the 3 bar sensor, or if I'd have to do a full after market setup.