building a turbo motor

[jmorgan]

ermm you dont know much turbos are known to make mad torque alot more then a centrifical supercharger

[Patrick Javert]

right, if setup properly on an engine. if dashiftyfella was to take nova's suggestion, he'd get worse torque than he would w/ my way. longer stroke=more lever action on the crank=more torque. more static compression=more torque. less static compression=less torque. dymanic compression, BTW, is controlled totally by the camshaft, and most turbo camshafts are setup w/ lost of overlap, thereby reducing total compression. More overlap=more power up high, but less torque down low. there are lots of variable to think about when looking into a turbo motor. max rpms, stall speed, turbo size( compressor housing diameter, exhaust housing diameter, exducer diameter, inducer diameter), power range desired by the turbo, camshaft specs, displacement(bore and stroke specs), ect.

[nova]

<blockquote>quote:</font><hr>Originally posted by Patrick Javert:
right, if setup properly on an engine. if dashiftyfella was to take nova's suggestion, he'd get worse torque than he would w/ my way. longer stroke=more lever action on the crank=more torque. more static compression=more torque. less static compression=less torque. dymanic compression, BTW, is controlled totally by the camshaft, and most turbo camshafts are setup w/ lost of overlap, thereby reducing total compression. More overlap=more power up high, but less torque down low. there are lots of variable to think about when looking into a turbo motor. max rpms, stall speed, turbo size( compressor housing diameter, exhaust housing diameter, exducer diameter, inducer diameter), power range desired by the turbo, camshaft specs, displacement(bore and stroke specs), ect.<hr></blockquote>

Yes. I did lot more research as I was trying to design my own turbo setup and I was rather wrong. If you are building a race only engine low CR is the way to go because it allows wicked amounts of boost but if you want an engine that will actually run at low RPM worth anything you generally need to stick with 9:1 or higher CR. Otherwise it will be a slug on the bottom end.

[ May 20, 2002: Message edited by: nova ]</p>

[dashiftyfella]

well if you guys know anything of the ledgendary gn engine then you know that they are any thing but sluggish at the bottom end. actuallywith a 120mph top speed they get pretty sluggish the higher you go. im looking into all the components now, soo far all i have is a shortblock. im looking into heads now thatll allow me to keep my stock hood and also allow me to keep my air conditioning. they made a front wheel version of this motor i think the bonnaville or something with smaller heads. buuutt with this smaller combustion chamber it'll be easier to overload the engines capacity and cause a backup that will make the air ocillate in the cylindars, and we all know what that means......back to the 3.4l motor. anyway the guys with these engines usually run 8.5:1 compression. and they run fast ive seen up to 40 psi, who knows how safe that is, but on a small block motor i find that amasing. hey whadda ya guys thing about this little idea. ok the astom martin has that cool decal on the side fender. if i had one on my car and i exhausted my wastegate through there gees that look sweet at night when you could see the little flame. but my body may catch all those carbon deposits ahhhhhh just a thought

[Patrick Javert]

40 psi on what, 110 race fuel???

[dashiftyfella]

uh i don't know i know the guys that run around 30 to 35 are running 92 or higher. go cheack em out at turbobuick.com

[nova]

<blockquote>quote:</font><hr>Originally posted by dashiftyfella:
uh i don't know i know the guys that run around 30 to 35 are running 92 or higher. go cheack em out at turbobuick.com<hr></blockquote>

At 30psi they'd have to have some serious octane. I'm not even sure standard race gas would be good. Might be using AvGas or something similar which is around 120 octane.

[Patrick Javert]

let's see, 8.0:1 compression, 40 psi boost, 160* thermo, aluminum heads, great air-air intercooler, water/alcohol injection, small nitrous shot(25-50), high efficiency cooling system, and the best engine/fuel/spark management would probly allow you to run 40 psi. I thinks that's pushing it, though.

[nova]

<blockquote>quote:</font><hr>Originally posted by Patrick Javert:
let's see, 8.0:1 compression, 40 psi boost, 160* thermo, aluminum heads, great air-air intercooler, water/alcohol injection, small nitrous shot(25-50), high efficiency cooling system, and the best engine/fuel/spark management would probly allow you to run 40 psi. I thinks that's pushing it, though.<hr></blockquote>

40psi is quite possible. Thinking a little deeper, the late 80's formula 1 cars were running 75psi. Thats with a lot of engineering going into the engine plus running almost pure toluene as fuel though.

[Patrick Javert]

I'm also looking at cost effective parts too. who's gonna spend that amount of money that F1 cars spend just to fix up a street motor? way too much money. I'd just get a LS1 or a LT5 equipped car and start from there. here's a better idea, drop a C5R 427 aluminum racing block LS6 into a 69 camaro/chevelle and add turbo's and sc's and nitrous to that. you won't have to worry about smog, and you have the latest and greatest high-efficiency engines out there in it.

[nova]

<blockquote>quote:</font><hr>Originally posted by Patrick Javert:
I'm also looking at cost effective parts too. who's gonna spend that amount of money that F1 cars spend just to fix up a street motor? way too much money. I'd just get a LS1 or a LT5 equipped car and start from there. here's a better idea, drop a C5R 427 aluminum racing block LS6 into a 69 camaro/chevelle and add turbo's and sc's and nitrous to that. you won't have to worry about smog, and you have the latest and greatest high-efficiency engines out there in it.<hr></blockquote>

I don't think anybody on this board has the engineering ability much less the money to produce anything near a Forumula 1 engine. Those are 100% custom jobs. Although they are nice.


In the late 80's they were producing 1400-1500HP on 90 cubic inches of displacement. Thats around 15 HP per cubic inch.

Apply that to something on the order of our cars.

Thats 3105 HP for the 3.4L and 3465 HP for the 3.8L. Thats all wishfull thinking though. :D

[wolf]

<blockquote>quote:</font><hr>Originally posted by nova:



Apply that to something on the order of our cars.

Thats 3105 HP for the 3.4L <hr></blockquote>

dear lord! that makes my goal of a tt3400 making ~400hp very modest :D

[dashiftyfella]

I MAY BE MISTAKEN BUT W/O MAJOR REBUILDING AN LS1 ENGINE CANNOT HANDLE MORE THAN 500HP WO TEARING OPEN THE BLOCK AND DOIN ALL KINDA CRAZY STUFF TO THE INTERNALS. ALSO HOW DO HIGHER CUBIC IN MOTORS HANDLE BOOST. AM I MISTAKEN TO THIN K THAT LOWERING THE COMPRESSION. AT THAT POINT ISNT THE ONLY BENIFIT SAYING THAT I HAVE AN 8 CYLINDAR, WHILE IM HOT CAUSE I NOW HAVE NO AIR CONDITIONING AND MY GAS MILEAGE IS TERRIBLE. I REEEALLY WANT THE HONER OF SAYING THAT I HAVE A V6 THAT'LL RUN DOWN YOUR FERRARI 40 IN THE QUARTER MILE. THESE ENGINES CANNOT HAVE 40 PSI ON STOCK INTERNALS WITH OUT HEAVY MODS. ANYONE KNOW THE

[TealV6]

<blockquote>quote:</font><hr>Originally posted by dashiftyfella:
I MAY BE MISTAKEN BUT W/O MAJOR REBUILDING AN LS1 ENGINE CANNOT HANDLE MORE THAN 500HP WO TEARING OPEN THE BLOCK AND DOIN ALL KINDA CRAZY STUFF TO THE INTERNALS. <hr></blockquote>

I beg to differ. We have a 2001 Firehawk w/ LS1 that has the Icon Twin Turbo setup installed on his. It's here in Detroit and he has yet to go into the motor. He has many bolt-ons, but nothing done under the heads.

I've also seen him pull low 10's and snap the aluminum DS like a tin can from all the boost he can spool up. Currently he's set to 10PSI with intercoolers.

How can the LS1's handle that. Well, simple. Displacement is great for boost. That motor was also made from GM with many refinements making it one of the better motors they've made.

Steve

[dashiftyfella]

but isnt 10 psi a little skimpy for a huge displacement engine? im not an expert but i would that it would take more pressure to even affect an engine of that size how does that work. also i hear with the longer stroke and bigger cylandars you have a bigger chance of getting detonation. also y would a twin turbo setup only run 10 psi. isnt that like around i dunno 100hp or so rough estimate. that shouldnt take the car anywhere near 500 should it. maybe with not with boltons and a turbo? but i have to admit that ls1 is one helluva engine. that one was designed to take 500 hp i would guess since they come out the factory with more that 400. but if you are talkin about a grand national engine i think they are more suited to handle boost since i hear they can handle 40 psi with no work "under the heads" and come out the showroom with 21psi. i know is isnt all that uncommon to see these motors near stock with bolt ons running near 600 650 hp and still be drivin daily. ohh btw i got my hands on one today. it was a 86 turbo reagal ooooooooo [img]graemlins/fluffy.gif[/img] that thing is all stock no add ons 200thousand miles, and he ran low 14's the other day still it runs good. 21mpg city 26 hwy. :D