Guest Anonymous Posted April 20, 2001 Share Posted April 20, 2001 I understand that SUs don't like forced induction and I would like to keep the SUs. If someone out there has done both a turbo conversion and a stroker please tell me which is 1) easier to setup 2) which is cheaper and 3) which is more trouble free. If I go with a turbo it will probably be a transplant of stock ZX parts. Any thoughts would be welcomed. Thanks ------------------ Once a horse walked into a bar and the bartender said, "hey, why the long face?" Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted April 20, 2001 Share Posted April 20, 2001 KS, as much as it sounds like you like your SUs, if a turbo setup is a consideration, I would strongly advise you and Zspeed to drop any notion of using the SUs. You omitted a key question. Which has the higher HP/torque potential? You must have a decent budget if you are considering building a 3.1L. IMO, outside of a b*lls-out Rebello-type N/A 3.1L, a 3.1L HP potential can be easily matched by a mild turbo setup that would not need expensive internals and it would also have gobs more torque. I know I sound like a broken record, but an L28T with the correct bolt-ons and proper tuning can easily make 300RWHP without putting undue stress on the stock internals. Of course, a turbo engine wheezes compared to a screaming 3.1L n/a and you must be prepared to learn about and manage a turbo setup. ------------------ Scottie 71 240GN-Z Scottie's GNZ Quote Link to comment Share on other sites More sharing options...
Owen Posted April 20, 2001 Share Posted April 20, 2001 I think Hoover was asking me about blow thru setups before? Search for his email on this site and ask him, he might be able to help. Owen ------------------ http://www.homestead.com/s30z/index.html Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 24, 2001 Share Posted April 24, 2001 Ok then, if I decide to go with a stock turbo, how much could be gained by the removal of the emmision equipment? A local used lot has an 81 that runs pretty good but looks like crap for 1250. How does the units on the stock gauge relate to PSI and what does it run if stock? Finally, if I install some type of boost control without an intercooler, what boost could I safely on 93 octane? Quote Link to comment Share on other sites More sharing options...
Drax240z Posted April 24, 2001 Share Posted April 24, 2001 First off I wouldn't trust the stock gauge as far as I can throw it. If you are doing this swap spend the extra $50 to buy a quality gauge. The stock setup ran around 6-7psi boost. $1250 isn't too bad a price, but I would of course try to get a bargain. If the car truly runs well, then it should make your swap easier. I wouldn't go around removing emissions stuff until I had completed the swap and had the car running... just too many variables if things are going wrong and you are removing things and doing the swap at the same time, and the car doesn't run right. With no intercooler, I'm guessing 9-10psi boost is achiveable. However, if you do that and fry your engine don't hold me responsible! I would gradually up it, see how it runs, then up it a bit more, being very careful to notice knock. Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 24, 2001 Share Posted April 24, 2001 quote: Originally posted by Scottie-GNZ: KS, You omitted a key question. Which has the higher HP/torque potential? You must have a decent budget if you are considering building a 3.1L. IMO, outside of a b*lls-out Rebello-type N/A 3.1L, a 3.1L HP potential can be easily matched by a mild turbo setup that would not need expensive internals and it would also have gobs more torque. I know I sound like a broken record, but an L28T with the correct bolt-ons and proper tuning can easily make 300RWHP without putting undue stress on the stock internals. Of course, a turbo engine wheezes compared to a screaming 3.1L n/a and you must be prepared to learn about and manage a turbo setup. I guess maybe I'm dense, but these two paragraphs seem to be at odds with each other. My gut tells me that a screaming 3.1L N/A will put out 3.1/2.8 times (about 11%) more power and torque than a screaming 2.8L. And I also think that I've heard Scottie say that a tweaked (but not much) L28T will put out 300 rwhp. So does a Screaming 3.1L put out considerably more than a tweaked L28T? Confused, Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted April 24, 2001 Share Posted April 24, 2001 Darn Pete, I reread my 2 paras 10 times and am confused what you are confused about If it is in reference to an L28T wheezing, I was referring to the sound. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted April 24, 2001 Share Posted April 24, 2001 Well thats ok, I've read the whole post about 6 times now, and I'm really confused now. I was fine before! (yes, really) - 3.1L will put out around 11% more power than a similar 2.8L - Mild/moderate turbo setup will leave them both behind. - Turbo setup will make funny noises, 3.1L will make other funny noises. These aren't the same funny noises. Does that clear it up? I think I'm more confused now. Quote Link to comment Share on other sites More sharing options...
fl327 Posted April 24, 2001 Share Posted April 24, 2001 i think when he means balls out, he means all out built 3.1 n/a because you have to be rich to rock that. now that turbo l28t is a great motor setup if your going l28, to me thats the only way to do it, you can boost and get great hp and tq for a little less than that balls out all motor approach, and you make whining noises and blow off squirts when you shift and rev!!!! hey look at hoovers ride the l28 turbo monster, that thing is hard!!! scottie got boost too, love it love it, im telling you my next step is a gnx/t56 booooooostinggggggggggg!!! maybe not. but i do believe turbo is the way to go with an l28 Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 25, 2001 Share Posted April 25, 2001 Scottie, thanks, that clears it up - the wheezing I took to mean lower performance and you meant sound. Quote Link to comment Share on other sites More sharing options...
jeromio Posted April 25, 2001 Share Posted April 25, 2001 You'd want to pay less than $1250 for that ZXt, but even at $1k, there's lotsa nice parts in there: front and rear calipers ecu and wiring CV half shafts T5 trans R200 (if you don't have one already) and mounting bits maybe the wheels I tried to find one for under a $1k in my area but failed. Ended up buying parts from the local yard (but not the engine, not yet anywayz). I don't think my wife or my neighbors would've liked the junk car in the driveway for however many months, but it would've been nice to have all the parts in one shot. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 25, 2001 Share Posted April 25, 2001 Funny noises as in Ha Ha, or funny noises as in, oh my God, what was that, that sounded expensive... Lone Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 25, 2001 Share Posted April 25, 2001 The only thing that I am confused about is the "balls out" part. I have driven with my balls out before but it didn't seem to make the car any faster. Sorry about that,,,I just couldn't resist!!! I think I will extend my front end and connect two L6s together. One will be a N/A 3.1 followed by the turbo. I wonder if that would mess-up the weight distribution? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 25, 2001 Share Posted April 25, 2001 Yeah, there would be alot of usable parts but the trans is auto(yawn) and the wheels are some kinda 3 spoke design that looks like the belong on a pimped out minitruck. Unfortunately, I have to sell some of the Jeep parts I have to buy my donor. So, if there is any Jeep fans here that need some stuff let me know. I may even throw in a auto trans for a turbo Z BTW, all jeep parts are for 76-83 CJ-5. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 2, 2001 Share Posted May 2, 2001 "My gut tells me that a screaming 3.1L N/A will put out 3.1/2.8 times (about 11%) more power and torque than a screaming 2.8L." If memory serves, you gain the torque from the increased leverage on the LD28 crank since the stroke is +4mm (which obviously means that you gain 2mm of moment arm on the power stroke). I have heard that this results in a geometric power gain, not linear. If you bored it out to 11% more displacement, the 11% gain would hold true. Just food for thought. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 2, 2001 Share Posted May 2, 2001 ok, why cant carbs be used with turbos? i always here how it is a bad idea, but why? what woudl have to be done for it to work and why doesnt it work? thanks Quote Link to comment Share on other sites More sharing options...
pparaska Posted May 2, 2001 Share Posted May 2, 2001 John, that's some good food. Great point - if you're adding stroke, you add to the torque in a linear fashion (I'd surmise - basic concept). The geometric thing stumps me though. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 2, 2001 Share Posted May 2, 2001 quote: Originally posted by hybridluver: ok, why cant carbs be used with turbos? i always here how it is a bad idea, but why? what woudl have to be done for it to work and why doesnt it work? thanks I don't know about other carbs but the SUs rely on negative pressure in the intake manifold to lift the needles out of the jets. If this is true then the turbo would cause the engine to run very lean. I am not sure what the result would be with the SU "upstream" from the intake turbine. I am not sure but I think this is called a draw-thru vs. normal setups being blow-thru. I am no expert(far from it) so I hope someone will either back me up or correct me on these statements. As far as other carbs, I have no idea-unless the high pressure screws-up the venturi effect. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 3, 2001 Share Posted May 3, 2001 I've read somewhere, not sure if it was here or not of a SU draw thru turbo on a Z. The SU sat upwind of the turbo and it works. However, it just doesn't work real well from what I understand. The early carb'ed turbo's were a stop gap measure, they worked, would put out horsepower, but could be lean or overly rich in a instant and there was no monitoring to fix it since it was all basically mechanical. Being as theres no way to really adjust fuel outside of the jets, the carbs are were typically jetted pretty fat so when the boost was on it didn't lean out the engine and detonate itself to death. As you might imagine, the fat jetting caused puddling in the turbo inlet, when the boost came up, a bunch of gas would come flying in, stumbling things for a sec, and then your flying. This is about all I know about carb'ed Z turbo's. I rode in a few setups (not Z's) in the 70's and while fairly impressive by the standards then, they really didn't operate well on the street due to the above mentioned fuel mixing problems. There were a few carb'ed turbo systems from Detroit, but they fell out of favor usually due to people not caring for them properly and doing the normal oil change at 7000 miles at jiffy lube if it needed it or not. They also would come flying in, shut the car with the turbine wheels blazing and then wonder why Mr. Goodwrench (or Ford or whomever) wanted to replace they're turbo bearings all the time, or why it leaked. They also were a tad weak when off boost due to lowered compression. The guys today with the digital systems, either factory or aftermarket and fuel injection are really eons ahead and can use much much more boost safely without frying the engine and drivability is crisp and responsive. Technology, ain't it grand!, Lone [ May 02, 2001: Message edited by: lonehdrider ] Quote Link to comment Share on other sites More sharing options...
Drax240z Posted May 3, 2001 Share Posted May 3, 2001 A perfect summary Lone, pretty much answers the carb vs. EFI turbo debate. (One day I am going to write a tech article about that, it seems to come up a lot) KS73Z, if you were to run with an SU, it would still open. The piston doesn't necessarily need vacuum behind it to lift it up, it just needs less pressure behind it than is on the face. If there is 15psi pushing on the face, and 14psi behind it, it will move up. The same principle as a drinking straw really. I think its *possible* to get a decently running blow through setup. However, you'd need to modify carbs to get them to work. I still think for the under $1000 that you can get an SDS for, its a far better answer in every way. Quote Link to comment Share on other sites More sharing options...
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