Guest Anonymous Posted August 28, 2001 Share Posted August 28, 2001 Hey there- I know there's probably plenty of v8 experts in here, so I guess this is the place to ask. My friend is talking all this crazy talk that I should Turbocharge my 350 V8. I told him I wouldn't because I'd need to replace some internals and because Supercharging is way, way, way more common for bigger motors, especially Yankee ones. You never really see turbo-charged V8s, especially on 350s. What is the reason for this? Does the super just perform way better? Is there some technical reason you can't turbocharge a big engine? Do americans just hate turbochargers? What's the deal here? Could someone explain WHY I should supercharge it (which seems pretty common) vs. turbocharge it (which seems very rare) so I can get my buddy to quit all his 350 V8 turbo crazytalk? Thanks, -Tyler [ August 28, 2001: Message edited by: etothen ] Quote Link to comment Share on other sites More sharing options...
Mike C Posted August 28, 2001 Share Posted August 28, 2001 To some degree, Americans have been slow to warm to newer turbo cars for the same reason that diesels have taken forever to gain favor. Crappy products in the 70's and 80's. Electronic controls are no comparison to the blow through carb turbos and mechanical injector diesels. As far as superchargers vs. turbo, superchargers are cheaper and easier to install with only intake plumbing and not complicated left to right exhaust plumbing. I myself prefer turbos as they make TONS of power without the associated parasitic loss and they are quiet. As I get older, I REALLY like the idea of fast and quiet. My Z/28 is fast, but it's loud and raucous, which has its place, but not for a daily driver which my Z is. I told a friend of mine 2 years ago that his nitrous injected 468 was a dinosaur in the fastest street car racing and that in 2001 all of the fast guys would be running turbo small blocks. Which has turned out to be spot on. After the "crash" (trying to back up an 8.63@160 ) he is now building a turbo LT1 for a '94 S10. I couldn't sway him into the Z car fold. [ August 27, 2001: Message edited by: Mike C ] Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted August 28, 2001 Share Posted August 28, 2001 Sure, a turbo can be dne. The plumbing will be a bear to squeeze in IMO and there will be heat issues underhood. However a turbo makes nice smooth sweet power and actually quites th eexhaust - it's awesome. Btu again, it's complicated, expensive, and not something you can find off the shelf. Something like an ATI supercharger can be ofund all day long and could be bolted in for a fraction of the time incvested in the turbo setup. 10lbs of boost is 10lbs of boost - it makes power! You may not have the ease of adjustment but done right a blower is pretty competitive vs a turbo especially when costs are added in. It is, unfortunatly, noisier which IMO is a downside. The P1200 on my 351W is so loud it nearly drowns out the sounds of the motor It's a nice sound though so I don't bitch to much Is all up to you. If you've got the skills and connections to make the turbo work then by all means go for it - you will NOT regret it fi you can get it bolted up correctly. Just PLEASE document the heck out of the install so others may follow your lead... Quote Link to comment Share on other sites More sharing options...
Drax240z Posted August 28, 2001 Share Posted August 28, 2001 Doing my intercooler piping today, it really wasn't that tough, and its certainly the hardest part of the 'plumbing' that a turbo setup needs. I used mandrel bends, cut to length/angle, and then welded together once in the right configuration. Total time to have workable piping was about 4hours. I'll probably spend 8 more making them look good though. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 28, 2001 Share Posted August 28, 2001 I've heard all this talk of the supercharger being cheaper. From my calculations even considering things like intercoolers (which both should probably run anyway) I don't see the turbo being more expensive at all. Consider that the average supercharger STARTS at 2k, and a turbo about 600.00 + intercooler (which are reasonable in the dismantlers)+ piping + BOV and Wastegate (which alot of turbos have one already on them) and it looks pretty close to a wash to me. That is assuming you can fabricate things, the exhaust would be a bit of a doddle, but I think that a pair of ramhorns manifolds modified would solve that right quick. If you don't have those fabrication skills, then I concede it would be cheaper. Power will be a bit higher on the turbo due to lower parasitic loss, and it is tons quieter. (I could take that screeching noise from the supercharger for about an afternoon even if it was quicker than all get out.) But as Jim said, higher underhood temps (ceramic coatings would help here some) and more frequent oil changes would be required. Internally the engine is about the same for either, both would appreciate forged parts and lowered compression. Both will probably require some fitment in the Z engine compartment, the turbo more so because of the exhaust plumbing. The supercharger will probably require some spacing so it'll miss the shock tower. So as you can see the answer is clear as mud, you pick the option you can live with and enjoy. Regards, Lone [ August 27, 2001: Message edited by: lonehdrider ] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 28, 2001 Share Posted August 28, 2001 I asked this question like this before and the response i got had to do with turbos having more complex piping and stuff like that. Anyway its not like turbocharging domestic engines isnt too off the wall. In the late 80's some popular mechanic team or something made a twin turbo corvette, and i think you can still buy kits for it off their website if i remembered what their name was. Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted August 28, 2001 Share Posted August 28, 2001 Turbocharging has become my most recent "Last Frontier" as I've read Hugh Macinnes book "TurboCharging" & am now reading Corky Bell's "Maximum Boost" & have found the turbo set up rather intriguing. According to Corky, the internal spark engine looses anywhere from 1/4 upto 1/3 of its power thru its exhaust....that translates into "Wasted Power" out the exhaust pipe. What I like about the turbo is that it isnt connected [directly] to the engine's crank & therefore is basically "free power" for the taking; as opposed to the supercharger which runs off the crankshaft pulley...the supercharger definately adds power/but robs it also as you mentioned earlier, can you say Parasitic Power Loss! Corky claims that the V engines or the Horzontally opposed engines do actually benefit from Twin Turbo's as the single turbo set up adds to the heat of the exhaust due to the size of the turbo required. Using a twin turbo set allows for two smaller turbo's but also decreases the actual heat as each bank takes advantages of its own exhaust & the piping doesnt include a cross over pipe connecting the two banks-therefore underhood temps are reduced. The real fun in piping comes in when you add IC-then things can get complicated...still IMO the complication is worth the bang for the buck. If I had the money I'ld go turbo-it just makes so much since now that I understand them (or should I say, in the process of understanding them). Even a 4.3 Twin Turbo would be incredibly attractive to me...eh, the Grease Monkey/Hot Rodder tells me to go V8 TT: who should I listen to, the evil voice or the good voice? For now I hace to listen to my bank account voice (party pooper!). Kevin, (Yea,Still an Inliner) [ August 28, 2001: Message edited by: Kevin Shasteen ] Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted August 28, 2001 Share Posted August 28, 2001 Hrm, ATI blower would run me a little over $3K. To do a turbo setup - twins - I'd have to have manifolds fabricated, piping fabricated, purchase two GOOD turbos, and route the exhaust etc. Don't forget that the turbo to intercooler piping will be more complicated than with a blower too. Ceramic coating is expensive and for a turbo app you're likely looking at the Swain white coating - looks like chalk. I've got this on my 302 manifolds and if it reduced heat I'd hate to see how it would've been otherwise! It didn't wear well BTW and could be easily scratched and stained. I STILL had glowing manifolds on many occasions I'd also argue that turbos DO take some power to run even if it's not readily apparent. Having said that - turbos ARE better IMO if power is all you're looking for. Turbos are nice and quiet and also take out noise form the exhaust. IF I were to do a Ford powered Z the manifolds in my garage would certainly be put to use. Yeah, I'm pretty tempted! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 28, 2001 Share Posted August 28, 2001 Guys, I have been looking at the advantages of both as well. I have a nice 2000 Tahoe that is just screaming for a supercharger. But it seems that, if you need injection with your supercharger you can add quite a bit more $$$$ to that initial $2k price. Turbo then becomes MUCH cheaper; at least in the case of my Tahoe. I suppose it can be a wash because you have to compensate fuel delivery for boost regardless of how boost is applied. I have never had either setup but am working towards a nice turbo L6 in my Z Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 28, 2001 Share Posted August 28, 2001 Actually with twin turbo's, (according to Hugh Macinnes's book) do require (or at least benefit from) a connection between the two turbo's. According to him, this is to smooth out the odd power pulses you'll get from just one bank of cylinders in a V type engine. He suggests a slip fitting between the banks. I'm thinking one of those stainless flex exhaust pieces could be used as well. Also turbo'ing domestic V8's isn't a real abstract idea either, Banks has been doing it for years, see his twin turbo Vette installations for clean. Aren't they used in Marine V8 applications sometimes too? No doubt, it's gonna get hot, I believe you totally when you say that, Jim. Tunneling all the exhaust into a small cast iron chamber is going to definitely heat things up. This may sound silly (or maybe just innocent and misinformed) but what if the turbo(s) was low in the front of the engine and heat shields were put on the turbo(s) that were ducted from the front (sort of like ducted brake coolers), perhaps that would help things out (at least while it was moving)? Regards, Lone Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted August 28, 2001 Share Posted August 28, 2001 Lone, Still on a learning curve here, where in MacInnes book (what page) did he talk about joining the twin pipes together? I could see how that would aid the signals putts to the exhaust on a horzonatal 4 or 6, v6 but on a V8 the signals are many; would there be a requirment on a v8 for the exhaust to be connected also? I intended for my statement to take into consideration the lower temps when Boost is brought about by each banks own turbo where as Boost brought about by a single turbo on a V/Block would increase temps even higher as a larger turbo would then be required; larger turbo means higher boost, higher boost means more power-more power means more heat. Jim, you are correct-so I've read, turbo's do rob energy when used; however, the energy loss pales into consideration to that of a supercharger. Still learning turbo's & enjoying every minute of it. Kevin, (Yea,Still an Inliner) [ August 28, 2001: Message edited by: Kevin Shasteen ] Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 28, 2001 Share Posted August 28, 2001 Lone, as I was reading the top part of your post, I was thinking the same thing - if the turbos are put down low in front, couldn't you duct air from the air dam back over them (shrouded from above) and back under the car or even if you got fancy, out a duct that went to the hood with GT40 type openings? Quote Link to comment Share on other sites More sharing options...
patzky1 Posted August 28, 2001 Share Posted August 28, 2001 i don't know too much about turbos. But wouldn't you need to lower the natural compression of the engine and/or O-ring the pistons in order to make a reliable setup (for racing)? this is a common problem with the I-6 engines if i am not mistaken. Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 28, 2001 Share Posted August 28, 2001 I think for the boost levels most likely used on a larger, o-ringing might not be needed. Plus the SB Chevy has 5 head bolts per cylinder which helps. Quote Link to comment Share on other sites More sharing options...
Mike C Posted August 28, 2001 Share Posted August 28, 2001 A similar setup to this might work in a Z with smaller plumbing and turbos. twin turbo Quote Link to comment Share on other sites More sharing options...
DavyZ Posted August 28, 2001 Share Posted August 28, 2001 What?!? How did a picture of my engine get in here?!? Lone, how is that bad boy for inspiration? Ohh, I feel like this is really doable--wouldn't it be great to pump this out on a budget with junkyard parts? Heh heh, I think the only real hurdle would be the exhaust manifolds... Great idea about the GT-40 style cooling for the turbo--some fiberglass, or even sheetmetal ducting to the top of the hood would make that thing cool like no tomorrow--at least the turbos would not be adding much heat to the ambient underhood air--the motor already puts plenty in there. Cowl induction hood, GT-40 split-style ducts, twin turbos, Chevy V8...Yeah, put me down for one! Davy [ August 28, 2001: Message edited by: DavyZ ] Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted August 29, 2001 Share Posted August 29, 2001 I wonder if that thing has ever been run and if it has, why is'nt the paint on the strut towers peeling? Under any kind of load, I bet those headers are GLOWING RED, just like the paint. Quote Link to comment Share on other sites More sharing options...
Mike C Posted August 29, 2001 Share Posted August 29, 2001 I don't know if it has run in the car, but I think so. I'm not sure about that picture, but what are those AN fittings in the front of the fuel rails? Plugs? Here is the main site, they have more info on the car including dyno specs Unlimited Racing Actually, couldn't find it going through the front, but here is the link I found first with motor specs and dyno #'s. Twin Turbo 377 [ August 28, 2001: Message edited by: Mike C ] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 29, 2001 Share Posted August 29, 2001 There's a pair of twin turbo 351 clevo's in my town, one is a daily driver, and has no bonnet ducting, but still manages to keep its paint on in the engine bay, the other is more of a show car but still gets driven regulary, there is also a chrome like ceramic finish available down here for the plumbing that is very durable and removes a lot of heat. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 29, 2001 Share Posted August 29, 2001 Yeah Davy, my thoughts exactly... Soon as I get my oxy-acet rig together then I can maybe look at fabricating some custom headers for such a endeavor. Theres a good article on the SDS website on fabricating headers and intake manifolds (along with alot of other cool stuff, definitely suggested reading there..). Theres a plumbing supply joint in town that might have the welded el's and stuff to make the exhaust durable and cheaply. I need to create (or buy) the flanges and go from there, but the engine needs to be fuely before I do that so I guess its not going to be a short term project money being what it is... Definitely down the road though. Regards, Lone Quote Link to comment Share on other sites More sharing options...
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