stock 1970 9.5:1 comp b4b intake demon 825 supercharger carb blowthru bonnet exhaust work on heads. 224/234 duration @.050 .480/.503 lift 112/108 lsa/lca there is another guy on here that runs an even smaller cam 212/212 i believe but i think if you could run a little moor exhaust duration it would be better like 212/224 no over lap mine has 5 degrees overlap and creates a little timing issues i run 4psi and thru a pair of t3/t4 .048 cheap ebay turbo's i think 400 for the pair new. the car weighs 4000lbs with 3.73 2400 stall runs in the high 11's on basically a stock motor. make sure you get head work done i tried to post pic put could not figure out how.
Awesome. Thanks for posting the pics. What do you mean by .048? Trim? A/R ratio? I have a single T04E-60/T3 turbo with a 0.8 A/R turbine on that V6(~204in^3) camaro I was talking about.
sorry it was a typeo i meant .48 but i looked at the turbo's and they are actually .50 a/r xspower brand turbo's
anyone out there interested in building a set of headers for my next turbo project i want to turbo charge my 72 skylark 12.80 455 or the 67 skylark
I realise you guys are talking about performance applications with the turbos , but I have a Chevy 454 dually for my tow truck and am thinking maybe turboing it . Any thoughts or advice ? Thanks in advance .
One thing with a truck is you wouldn't need as big of a turbo(s). Since you're not likely to be screaming the motor through 6000rpm (at least I wouldn't think) you can go with one that responds better at lower/mid-range rpm levels that might run out of steam if you really wanted to open it up at high rpms. Smaller turbos usually spool up faster so you'll have the usable boost sooner. They'll also give some good torque in higher gears/low rpm with WOT since they spool faster and that's probably what you'd want for towing.
I too am in the midst of creating a twin turbo 455 setup for my 70 Wildcat. I've seen it done with other large car makes, launching off idle 2.78 gears, low 10's in a 4500+ lb car. Its just that major WOW factor. It was my incentive to start.
a local exauhst shop fabed the headers for my camaro but it was a lot of $$$2500$$$ and i just am not willing to spend that kind of money again i think i have another shop here in oregon that will build them for $800. i guess i could do it myself but i dont know how to weld.
You are very right I will not be turning that motor 6000 . Just need some extra power since I am planning for a much bigger trailer . I need suggestions on where to find the needed parts , also some of the better brands .
I don't mean to discourage Turbo455 but I have heard nothing but bad things about XSPower turbochargers. There are tons of message boards around that warn not to buy them and warning to stay away from ebay sellers that sell them. I've heard anything from the cast compressor housings crack and break in half, to the reason they're so cheap is because the mix and match parts to make a turbo and don't bother checking tolerances or balancing the units. Here's one particular post: http://www.thirdgen.org/techboard/power-adder/325843-trying-warn-guy-about.html One inexpensive brand that I have heard good things about are Master Power turbochargers. Master Power is a company in Brazill and I've seen several people use them for long periods of time with good results. If you don't mind spending a little more money, then Turbonetics is a good place. For wastegates, Tial is a good brand. Or you could get turbos with internal wastegates. For general turbo stuff, www.atpturbo.com is a good place to get what you need. I put together a simple Excel spreadsheet(attached: download it and change the .txt extension to .xls It wouldn't let me upload a .xls file) to try and size a turbocharger(s). Simply enter your information for the variables(in italics) and then look at the end result of Pressure ratio, and Air Mass Rate(lb/min) and compare that to turbocharger compressor maps. There are many here: http://64.225.76.178/catalog/compmaps/fig1.html You can chose the RPM target in the Excel file where you'd want the most power or where you'd need it most. Then try and find a turbo compressor map that is near the center of those circles for the lb/min and pressure ratio. Those circles are called efficiency(shown as a %) islands. The ones in the center are more effecient than the ones towards the outside. The lines with the tens and hundreds of thousands on them are turbo shaft speeds at those conditions. For a twin turbo setup I divided the Mass Air Rate by two just to the right of the total for the engine. These calculations are a little simplified since the temp doesn't directly corrilate to the pressure of the air...since air heats up when you compress it. But it doesn't have a huge affect on the numbers. To me, for moderate levels of boost and a peak around 4200-4500, a TO4E-60 compressor looks pretty good. It would start to run out of steam, or at least efficiency around 5500+. That is for a twin turbo(2 TO4E-60s). There's also the turbine to think about. The turbine really has a lot to do with how the turbocharger spools and how fast. A lot has to do with A/R ratio of the turbine housing. I would think with a twin, if you again wanted boost early and don't care about upper rpms an A/R ratio of about 0.6 on the turbine side for each turbo should do pretty well. It will start to choke the engine off some though at higher rpms. I'm thinking of doing a twin turbo on my BBB but for performance. I'm thinking about going with two T70 turbos.
Ok, I changed it around a little. I added some fuel stuff and also made the temp corrispond to the boost pressure run. I also added a volumetric efficiency of the engine of 85%. This is still of course a simplification. There are tons of different ways you could set up your engine to make things different here. This is just textbook stuff, not real world, but it's still a good place to start. Just keep in mind that the fuel requirements are directly tied to the RPM entered. So if you go higher, you'll need larger injectors. Again, download and change the .txt extension to .xls
I saw the same posts about sxpower as well but it was after i already installed mine. no problems so far. and as far as the a/r my twins are .50 and i could get 6000 rpm's no problem i only know that because my check valve for the trany went bad and the boost was not allowing the th400 to shift. I fixed the check valve and it started shifting at 5000 again. But I have a boost creep problem do you think that it is because i should run a .6 a/r instead of a .5 a/r. and yes i am sure the waste gates are working however the waste gates maybee to small.
Also, here's a good resource for turbo stuff: http://www.forcedinductions.com/ Also check out the Turbo Selection 101 and Turbo Engineering Explained.
I've wondered about keeping the a/r smaller and using larger wastegates to bleed off the excess exhaust flow. I don't know if this would allow you to "have your cake and eat it, too" or not. (faster spool up without the restriction in the upper rpm range)
Hmm...I don't see why the heck not. One thing to make it more controllable however would be an electronic boost controller. Since a large wastegate on a small turbine could make for some really jumpy controls. If you had a nice controller it would just barely start to crack the wastegate open when you want boost and then fully open it at higher rpms. Even then, a large valve coming off the seat might cause a large loss in turbine inlet pressure, meaning losing boost. I think it would be tricky to make it respond well. Now maybe a multi-stage wastegate would work. Say one small one that'll control the small turbine well, and then at higher rpms open up either an additional small one or an additional large one. It's still something to wonder about however that pressurized air is like anything else in that it will follow the path of least resistance. IE: a large open wastegate might be easier to flow through than the restriction through a turbine and the turbine will lose speed, losing boost. But it might be made to work...
By boost creep do you mean it slowly increases past your desired max boost? Does it do this gradually and continually with increasing RPMs? I would say it's from a small a/r and wastegate like you said. You may be able to get to 6000 no problem, but does it feel like power is leveling off or decreasing? Although that might be hard to tell if the cam and heads don't like breathing much up there. I've heard the old stock ignitions don't really provide much up there either.
