RB26DETT vs. LS1 (aluminum)

[Guest tt350]

Just to be sure im goin the best way possible,

 

Off the top your heads, what is the advantages of the Rb26dett over the Chevy small block. What are the disadvantages,

 

Which one is cheaper to build, and which one is easier to build to high hp levels (stronger stock)?

 

Im not planning to switch, but I want to know if the RB26 is better or not. I researched it, but I just want to know your "educated opinions", I mean what you saw at the track (any type), feel, torque and hp, you know.

 

The one disadvante that kills me for the Rb26, is that it missing that sweet v8 rumble. I love that sound, and I dont wanna lose that. But thats not as important as everything else.

 

Also, which is more complicated to swap in, the RB26, or the v8.

 

Scottie, I know your sick of this by now, but im very knew to conversions. Anyone want to know about BMWs?

 

Geez I hope I dont get killed for this!

[stony]

10K should get you 500+ rwhp out of a rb26 this includes the motor tranny mods to do the swap a good intercooler, injectors and upgrade turbos. after that youll need alot more chassis work just like a hi power v-8 would. I personally like the sound of the rb26 at full booste and wide open external wastegate.

[Mudge]

Ouch, RBs seem like nice engines but 500RWHP out of an LS1 is childs play NA, IF you get the right heads, and I've seen some real duds out there, of course I like everyone have a favorite porter

 

LS1 with ported heads (not LS6), stock bottom, 230/242 hydraulic cam and LS6 intake puts out 470 RWHP when tuned, 6 speed of course.

 

http://www.advancedinduction.com Site may not be much, but Phil and his buddy are super-porters. Budget ported LT1 car put out 412 to the wheels with a 230/238 Ultradyne. Keep in mind most peoples "Stage II" fully ported heads claim higher numbers than are FACTUAL, and hardly ever see north of 400 RWHP on LT1 cars. Phils buddy is a school of SAM graduate and does some high profile stuff, they will get my biz with every car I put heads on.

 

Turbo cars can make awesome power, but why not do it with cubes. Trying to stretch 4 and 5 HP per cube out of a tiny engine gets EXPENSIVE, no matter how impressive it is, it will also be very peaky power unless you go with a progressive turbo setup, or a quad progressive turbo setup like some of Porsche's hot 1.1M, 100 car limited production uber-Porch.

 

The local fast turbo GN guy on the BAMotor list got rid of the six which was doing something north of 1100 HP, and now has a 1680HP V8 which got him out of his former low-9 life.

[stony]

he did say stock i think. can you get 500 hp to the wheels from a stock ls with changing heads?

[Mudge]

Ahh, without opening the engine is another story. Big solid roller might do it, I know of an LT1 that did 460HP crank with a 244/244-114 on stock heads, but generally NA means opening the sucker up vs turbo, which is why I have my own turbo car adjustable power levels on the "cheap."

[Guest Your Car is Slow]

for 10k...you could have alot more than 500hp from an LS1

[Mudge]

Yep, buy in for RBs is too crazy for me, I'll stick with the 20 year old rice banger for awhile 10k would get you a stroker and a blower setup if your carefull.

[Guest tt350]

Do you guys know if it is possible to put a small turbo on a completly stock LT1 or LS1, and make about 450-500? with the 9 to 1 or whatever pistons they come with.

 

I found a T3 turbo for $15 bucks, and I want to play around with it before I get into the GT45's

 

The enigne I had in mind was a Dart 350 (iron) with 8.5:1 pistons, steel crankshaft, forged rods and everything (probably the most expensive part), and upside-down shorty headers to smack the turbos on. For injection, I was just goin to put a Stock ECU off a corvette or something? Any suggestions on ECU?

 

Thanks

[Tim240z]

Well, I would look into what the supercharger specs are. Boost is boost, so if the motor can handle a bit of supercharger boost, then it should be able to handle a bit of turbo boost?

Tim

[Phantom]

http://www.procharger.com

Should be able to get about 500 HP with new injectors and ECM reprogram on an otherwise stock LS1. Cost you about $6,000 in parts and a weekend of your work.

[Mudge]

450-500 crank? Sure, you could do it, however most people are running 60:1 or larger, 60:1 is considered on the small side for a V8. Avoid detonation and you should be safe. However you could make the power with some headers and throwing in a solid roller, and not have to do any turbo fabbing, although if your going to turbo anyway then doing it the first time is probably a good idea.

 

Longevity over the point of 500 crank HP on one of these cars is a bit iffy, 550+ is where you pretty much admit its going to break eventually, rods wont take it and the crank flexes pretty badly.

 

I would avoid the Vette PCM unless you buy a Vette, the C4 uses a master computer and that to my knowlege would cause problems when trying to stick it in another car, although if it has the same PN as the FBody PCM then you could flash over it safely, again were talking LT1s here there are further differences when we talk LS1s. Imp or FBod PCM and use an FBod file is what I'd do, 94 or 95 PCM only, unless you want speed density and chip burning hassles, but you can turn your 94/95 into SD mode anyway with a simple switch (in the PCM).

 

SD may be the way to go with boost, but I know someone running 9s with the MAF on a stock ECU and a low impedance injector box of his own design (he sells them also).

 

LS1s are still pricey to work with until Tunercat comes out with something, they were shooting for spring but now I'm told summer this year.

[Guest JAMIE T]

If you have not seen this yet, check it out. http://www.darius240z.com

 

LS1's and LT1's have too much compression(OVER 10:1) to run any real boost in stock form. I attended a Dyno day last fall and some guy had a Powerdyne supercharger on an otherwise stock LT1. That junk only made 298RWHP. What a joke. My stock bottom end, heads/cam LT1 made 350RWHP the same day. In the website above, you will see a 600hp LT1 powered 240Z. If you can get the vidz to play, you will see what 600HP does to street tires in a 240Z. I did get to watch a Procharged Z06 Vette punish the dyno rollers with 700+ lbs/torque and 600+ HP. It was AMAZING. That was a fully prepped LS6 and big boost.

 

I haven't been keeping up with your posts, honestly, I thought it was a joke. I see now atleast your goals have come to a realization. The chassis is more of a concern for your plans. What sort of road racing do you plan on doing that requires that much HP? What is your REAL budget? Dollar for dollar, cubic inches will win. The guys with little turbo motors like to claim they can make as much HP with a turbo. BIG DEAL!!! For the same(and sometimes less) Money, you can turbo the big(I'm talking V8's) and make road rash out of the small turbo motor. And like mudge said, 60-1(turbo) is minimum on a 350 cube engine. That T3 will only make for an oily paper weight.

 

One day, I will turbo a V8, Probably a LT1 with fully built bottom end, and dished pistons. I would only use a standalone engine management system for something like that. A T76 is the turbo of choice for a single, and a pair of T4's would get the nod for twins.

[Mudge]

Powerdyne sucks, he must have had a 4psi system though to only do 298RW! The 6.5psi setup is supposedly an additional 75HP, really on the low end/wasting your time type blower.

 

cc306 in a stock head LT1 will put out 355RWHP, wont pass smog though (no matter in a 240Z!) Solid roller I believe I mentioned above, 244/244-114 400RW in a 93 with a loaned chip (bad tune). Mine was hydraulic, stock 3.42 gears and was very streetable, open loop tune got me 17-19 MPG average when I was daily driving it to work in San Fran (no freeway stuff), 411RWHP @5900 (ignition miss) at the wheels, 320RWTQ @ 2500, peak of 385.

[stony]

10k is the complete drivetrain.... you cant tell me stock tranny behind an ls1 can handle 500+rwhp without being modded can it?

[Guest Your Car is Slow]

Sure it can..provided you arent launching on ET streets or other slicks.

 

Traction breaks parts more than horsepower

 

there are numerous LT1s well over the 500 mark here in town...they go through clutches like crazy...but the T56s seem to hold.

 

The LT1 bottom end is alot stronger than the LS1 bottom end..the only downside is that the Fbody/bbody bottom end only has 2bolt mains vs the 4bolt mains of the vette LT1. If you want to run big boost/power/etc...4bolt mains are pretty much a must.

 

not hard to pick up a 4bolt main shortblock LT1 for less than 300 or so.

 

not to mention LT1s are alot cheaper to mod than LS1s.

[Mudge]

LS1 early rods are not known to be strong, but they seem to hold up overall.

 

T56 is in the 9s on a little over 3400 pound car, WITH slicks, how long will it last who knows. He had the trans cryoed though, there are also upgraded output shafts yada yada if you want to get fancy, but 500HP is not going to be pushing it all that much on a road raced 240Z that weighs about as much as I do I had no hesitations in dumping the clutch on my street tired, 411RW LT1, it was fuuuuuuuuun

 

I'd love to have an LS1 project, but as basically just said, it is a good bit more expensive for not a huge gain, just a bunch of small "ooh neat" which adds up to a nice overall difference, but for the bread, it could be spent elsewhere, they just happen to have the best numbers put to the ground of a Chevy SBC in near "stock" form, or even stock for that matter.

 

There is an LT1 with SBC 18º heads and a mild hydraulic roller doing something north of 600HP, at a peak RPM of I believe 6400 RPM, so they have potential too but other than the block your throwing alot of things away so to speak. As far as the LT1 block goes it is believed to handle 1300 HP just barely, although I haven't heard of a cracked one on a blown car yet.

 

Jeff Collop, 390 RWHP NA + 200 shot on a stock bottom LT1/T56! Now I dont think that thing had alot of life in it, but he NEVER blew it up, he has a 383 now though

[BRAD D]

The RB25DET 5-speed transmission is big, it looks bomb proof. I think it is the same as the RB26DETT AWD 6-speed transmission just with one less gear and no T-case. And the guys with GTR's with over 800hp launch hard.

Stony you should post that GTR-700 vid you sent me, That will show them how hard they launch .

[stony]

that car is an all out race car with aftermarket everything in the drivtrain. pushing over 1200HP. i have no place to post it but is available at http://www.exvitermini.com/movies/896runs.zip

[Guest tt350]

By the way, exvitermini is who "pushed" me to the RB. But look at his engine block prices. OML!

 

What is the diff between the LT1 and the LS1 anyway?

 

Thanks for all the input.

[Guest JAMIE T]

The LS1 is completely redesigned from all former Small block chevy V8's. The LT1 shares many of the same features as "regular" SBC's. It coolant system has been reversed. It has no provision for a belt driven water pump. The heads are LT1 specific, though regular SBC heads can be used with modifications. The block is iron, LS1 Is aluminum. Parts a re generally cheaper for LT1's since most parts are reguler SBC parts. The T56 is STRONG. Vipers use them! I've had my '94 Z28 for about 5 years. The trans is holding up just fine. The clutch is done, I've got a SPEC clutch and Aluminum flywheel to install when the time permits.

 

I don't know much about the RB26DETT, except they look awesome under the hood of a Zcar. If money was not an object for me, I'd go RB26DETT just to make onlookers crap there shorts when they see a "ohhh, ahhh, a GTR engine!" But only import tech heads would know anything about it. A V8 Z gets the "Oh, you put a 350 in it". But is recognizable to most car people.

 

I think a mildy built LT1 NA would suit your needs fine. And get you going (car actually running and driving) sooner. Repair parts are easy to come by etc...