XLR8NSS

iTrader: (4)

Try checking in the Conversion and Hybrids section for the dimensions. I'm sure those guys know with all the crazy chassis they've put LS1/6's into.

I have a question. If you could get 800hp without revving to 8-8500 would that be ok with you? I think 800hp could be had relatively easily with the right motor/turbo setup but, the 8500rpm will make short work of the motor at those power levels. IMO I'm not saying the motor will last forever with 800hp alone but, adding the stress of spinning to 8500rpm is going to shorten the life of the motor(all components) drastically. How about an aluminum 382(stock bore, 4" stroke) or a iron 408 that only needs to be spun to 6000-6500 to make 800hp?

A 408 built to handle 14psi could make 800rwhp by 6000rpm or so. A 382 wouldn't need much more if you wanted to stick with the aluminum block.

jmicaelk

Well OK, if I change the whole thing a little bit and say that I want it to be able to rev to 8-8500 RPM now and then, don't plan to rev that high all the time, so what would be more realistic for a 800HP engine. Or do i have to get some special Aluminum block and heads from some manufactor and if so ho do you guys recomend, saw that Dart charged around $4000 for their block.

Thanks Micael

XLR8NSS

iTrader: (4)

I'm not saying change what you want but, I'm just wondering why you want to rev that high at all? The LS1 motors can make the power without spinning them that high.

If you really want to spin that high then a solid roller is pretty much a necessity. I would contact Futral Motorsports or Thunder Racing about the motor because they seem to have quite a bit of experience with solid roller LS1s. Links to their websites can be found over in the sponsors to the right.

jmicaelk

Thanks man, well I newer ment to rev that high all the time, jsut we needed, as to achive lowest possible 0-60 MPh, when the car would reach 62MPh on first gear, which should give me a lower time, but also be able to reach a top speed of 400 KM/h or about 250MPh.

Micael

XLR8NSS

iTrader: (4)

Sounds like an interesting project. What size tires, rear gear ratio and transmission(ratios) are you going with?

jmicaelk

So far I'm looking at a Porsche GT-3 box or a Twin Turbo Box, the GT-3 has a 3.818 first, which would make reaching 60MPh on first hard without high RPM's, final gear is 3.444, have heard that all gear's 2-6 could be changed but 1st I don't know if it can be changed. 6th gear will be something like 0.750, but can be changed to 0.675 or something close to it, fo more top speed if RPM's won't reach over 8500. The tires back will be 335/30/18 or 19, haven't decided yet, it all depends on wheels and what I can find for the track and for the street.

Micael

eviltwins

I think you need to make some realistic goals. 800 RWHP in a light *** ultima GTR is just plain dumb to think you're EVER going to be able to drive that on an 18 or 19" tire. That much power with that little weight would build a car that would likely go 160+ through the traps in the 1/4, which is pretty damn unreasonable for a street car. Make up your mind, if you want a motor that will do 8500 RPM's and propel you to 250 MPH, go build a 4.6 cobra engine with some billet rods, good pistons, port the hell out of the heads, get some custom ground cams, and bolt on a centrifugal blower. A pushrod motor for a street car has no business revving to 8500, and 800 RWHP has no business in a sub 3000 pound car.

jmicaelk

I only asked if it was possible to do it and have so explained at least twice no, yes I would like it to be able to rev to 8-8500, I didn't know if the LS1/6 was able to do that, so thats why I asked. I just don't understand why people keep telling me what I can't do, insted of telling me what I can do. 800 rwhp in a streetcar, well you say you have a turbocharged Mustang, do you know how it works, starts wondering if you do, but if you don't, you can turn it up and down with boost, so that way I can have my 800hp when I need them, and less when I'm on the street. And don't call me dum for wanting to have it in a light car you then have to call a lot of people dum, I would call people that want to have heavy cars and then make that up with power dum that car might work on the straight but I would hate to have it on the track, and what the hell is wrong with 18" or 19" tires, you wanna put smaller tires on the car, well that is just plain dum. So I hope that will help you understand better, and the reason that I have asked about the LS1/6 is so that I'll have more engine choices, when it comes time to build the car.

Micael

XLR8NSS

iTrader: (4)

Anyway you can drop the rear gear ratio down a little bit? A 2.73:1 rear gear could get you 62mph at 8000rpm in first and 250mph at around 8500rpm in a 1:1 trans ratio rather than using overdrive. The 3.44 ratio will get you 250mph with the .75 ratio overdrive but, not the 60mph in 1st. Might have to compromise on one or the other.

For those type of rpms I'd go with a custom short stroke forged crank, strong rods, solid roller cam, big bore aluminum block(either resleeved or preferably a C5R case). The 4.8L truck crank has a 3.27" stroke but, I'd hate to test it out at those rpms and power level.

Check with those shops I mentioned earlier on the solid roller stuff. They can probably help you out on motor specs.

I'm not sure how you plan on keeping 800rwhp in check in that light car but, it sounds like it would be fun.

Good luck.

Pro Stock John

iTrader: (34)

If you don't care whether you build a Dart small block, LS6 or a LT5, I would probably go with the Dart block and build a solid roller motor with aftermarket heads like Brodix Track 1's or something like that. I don't know enough about ZR1's to know how high they can buzz or what kind of valvetrain they have but when you run over 8000 rpms you need some fancy stuff.

I'd run a 4.125 bore Dart block which is like $1999 with steel mains from Summit, and a set of good aftermarket heads which are like $2500 assembled. With a 3.48 stroke you could build a high revvin' SBC that displaces maybe 377ci and that can AND SHOULD rev to 8500.

I think the LT5 would be my last choice based on how expensive a stock crate motor is, unless I saw data regarding the valvetrain that validated going that way.

jmicaelk

THANKS A LOT GUY'S, no I'm getting somewhere, is the block from Summit Aluminum or steel, and if not Aluminum how much would I have to pay for a Aluminum block. The heads would that be arond $2500 for both or each.
Don't know if I can change the final drive and if so how much, but I'm looking in to it, I also hope to be able to change first, but that seems to be harder and I don't know if the would weakend the gearbox. And since this box only hold some 650lbs of torque I will have to try to build an engine with high HP but lower lbs, been playing around with the Demo of DYNOSIM and from that it seems to be possible to build on. Have anyone here used Dynosim, planing to get the full version and really try it out, should be a good investment for only $130, test's have sown this program to be right on the money with power and time slips. And what is a CR5 case.

Again Thanks a lot guys.

Micael

XLR8NSS

iTrader: (4)

The Dart blocks are cast iron. The "C5R case" is just a LS1 style racing block. It is much beefier than a standard LS1 block and comes with a 4.125" bore. It's aluminum but, cost somewhere around $6000-6500 just for the block.

GM Performance makes standard small block Chevy aluminum racing blocks. They'll set you back over $4000 dollars brand new for just the block. If you can pick up a GM Performance parts catalog they list all the available blocks.

To do what you want it's probably going to be cheaper to do it with a standard Small Block Chevy rather than an LS1 based motor. Parts are cheaper and the R&D has been done many times over to do what you want.

I think it's probably possible with a LS1 but, you'd be sailing in uncharted seas I think. This is just me, if I had a chassis and could use several different engines I'd pick the SBC based on your criteria.

Seeing an LS1 in there would be pretty awesome though.

Good luck.

hondadream50

Just buy the Gm Crate motor

572ci/720hp/685tq motor .... it comes with a Gm warranty.. Cant beat that.
I also seen the street version go for around 5-6 grand.. They produce 620hp

jmicaelk

Well I found this Dart Aluminum Block , don't know how much power it can take, but could it be used.
But reading your post and reading an article somewhere about resleving the LS1 and using a 4.125" bore, I think that the LS1 can work and I would love to try it, but on the other hand if the standard LS1 block can handle the power I think that 5.7L is volume enough for me to reach the power I want.

Thanks Micael

SDB

iTrader: (7)

Do you have the $35,000+ it will take to do this? Sounds like someone is wanting waaaayyyy too much.

jmicaelk

And how do you get it to be $35000+, I would ike to see some numbers on that.

Thanks Micael