ClimberD

Awesome, thank you. Can't wait to see your solutions and progress. Any reason you are choosing the GM power steering pump instead of Audi? Just curious, as I haven't spent too much time figuring out the accessory details in that respect. Somewhat similar to you, I'm going to use some original accessories. 190A alternator is insane. I thought Subaru's 140A was a lot.

What ECU solution are you going to use?

timmmy

Morning,

I actually managed to spend about 6 hours on the project yesterday and figured a lot more of the details out. Still a lot to do but I feel like I am getting a better handle on it.

I was originally thinking that I would retain as much of the LS accessory drive system as possible, hence keeping the stock PS pump made sense if it was hanging on the LS4 accessory mounts. In looking at it more yesterday, it seems the best approach for this project is probably to use the LS4 crank pulley and make custom mounts for all the Audi accessories (AC, alternator and PS pump). That way I can mount them close to where they were originally and not have to rework any of the Audi plumbing or wiring (too much)

I am pretty convinced that I am going to go with an electric water pump as even the LS4 water pump is a chunky bit of kit.

On the ECU end of things, I am still trying to figure that out. What I do know is that Unitronic can 'dead head' the RS6 ecu, meaning they can flash it so that it can run the dash etc and I can feed it things like RPM, pressures and temps so all the warnings will work, but it wont put up errors related to not running the motor. I am on the fence right now with regards to the decision between a stock GM ecu with http://www.hptuners.com/ to allow me to tune and change the VIN so the OBD port reports correctly at inspection time. My other option is to use something more SEM standalone like the HP dominator or Mast motorsport ECU. I have not done enough research into ECU stuff yet to figure that out. Longer term I will probably end up changing to an LS3 and adding some boost to the motor, so the difference between a stock ECU ($200 on ebay) + HP tuners ($600 for pro) (total $800) and a more future proof SEM at double that is a tough call.

If you have researched ECU's or anyone else out there has some input it would be greatly appreciated!

Cheers and keep up the good work and great documentation.

I will probably start a thread on here for my project tonight.

I have a thread over on motorgeek currently: http://www.motorgeek.com/viewtopic.php?f=6&t=39901

Sarg

iTrader: (6)

Give these guys a call:

http://www.sspwiring.com/LS1_Wiring_Harness.php

I have been very pleased with my dealings with them. You can get ECU from them, hp tuner and harness. They will also do package deals, which is what my friend and I got.

ClimberD

Engine selection:

the more I looked at it, I must agree with Timmmy, that 1/2" is not worth it for the hassle of the LS4. I'll get an LS4 t-belt cover, harmonic balancer, and perhaps water pump housing and idler pulleys. That's IT.

The downside to the LS4 is the amount of crap that I would need to swap off of it:
intake manifold
throttle body
DOD valley cover
lifters
oil pan / pickup

And then I would be stuck with the LS4 footprint going forward, which may prove to be a hassle if/when I switch to the next LS motor.

Therefore it would be wise to go with a 99-2000 F-body LS1, and accept the 1/2" length penalty.

Turbo Selection and such:

I have designed my single turbo divided T4 manifold on paper, which will be true twinscroll and will utilize proper cylinder pairing for the full effect. The key then will be picking the right turbo. I have been told all sorts of things, but I happen to be sided with Sarg that the Borg Warner Airwerks 91-79 will be the best bet for streetability. It was designed for twinscroll, not a singlescroll design with a twinscroll housing slapped on it.

I can always go bigger later, as there are some nice-looking S400 units. I know a lot about the S300 family, but not the S400. It appears the trend here is to mess with the S400. I never understood doing this... and I usually find once a hybrid trend finally gets enough attention from the right people, it gets called out and then fizzles out... we'll see. I can't imagine the S400 family being of poor design, though perhaps a particular S400 might not be the right choice for a certain person's power goals in the first place, and would thus get messed with. I don't know...

Engine Management:

I'm 95% decided on MS3x (megasquirt). The new stuff is solid and supports all the LSx coil and injector functionality, different inputs for cam and crank, boost control, controls all the auxilary junk, solid. All it doesn't do is DBW, which is fine. I'll get cruise with an old DBC cruise module, most of which don't need PCM input.
I have no need for the extra hassle of the stock PCM, though it would certainly work fine too.

I'm going to trial the latest MS3x on my LS400, and if I like it a lot then that's what I will do, and that will be the final decision point.

Sarg, thanks for the link to the PCM wiring, and all the other good info!

Sarg

iTrader: (6)

Actually I would only get the 91-79 if I was going twins. I would definitely go with the s480 if I was going single. The 91-79 would work but you would be very limited in the amount of boost you could run.

I personally am going to go twin ebay 76mm t4 turbos (vs the 91-79's 66mm) for now and if I like the swap I will make a more permanent turbo choice when I go built motor.

I am also going stock ecu and speed density tuning via HP Tuner Pro.

Sarg

iTrader: (6)

Also check out FI turbos. They have a s480 for $899 which is a t6 turbo, but they can put a t4 turbine housing on it for a bit more.

ClimberD

Apparently the S400s are heavy as hell (though not without reason) but every bit counts in a nose-heavy AWD car. Thanks for the tips on the other turbos. Looking at the 91-79 again and again, I can't see it being useful past 5000rpm, if that.
I dont know how on earth some guys are using 1 bank (2.85L) to spin a "76mm" turbo. How is that not insanely laggy, though in saying 76mm, the other 3 important numbers get left out, etc.
Biggest I would ever go on a TT is S200SX 75-70, for streetability. However that 75 is sure not the inducer... I love those S200SX turbos.
This turbo stuff is Frustrating!!!

Sarg

iTrader: (6)

Think of it this way...there are guys getting the 66mm turbos (9179) spooled at 3800 rpms on a 2.5. Now take half of a 5.3 at 2.65L and it should be able to get a 70 spooled at about the same as the 2.5L does that 66mm. So twin 70mm should be in the 4000 or less rpm area. Also take into account not having a 8 foot exhaust tract like the subaru

ClimberD

91-79 at 3800rpm on a 2.5? No. It's still building boost at that point, and will lag to get back on boost after shifting even at 5000rpm... but that's neither here nor there.

As the STi - Evo comparisons indicate, twinscroll is somewhat similar for spool to short runner length, and twinscroll EVO manifolds trump EVERYTHING. Mind you I'm looking at what many people here consider radical crossover manifolds, so things are on the table that most people here have never seen, but you knowing Subarus have seen: crossing the width of the engine bay AND matching cylinder pairs for a true twinscroll, which is how I consider doing twins It's also how I would do a single turbo TS, with literally 4 small diameter wrapped primaries coming under the oil pan and merging with their opposing firing order cylinders, then secondaries merging 4-2 at the divided T4 flange.
I see your logic, as was largely how I calculated my twins, but what I don't know is this:
For a street car with AWD traction and proper diffs, is there any benefit to having a turbo add significant airflow to the <3000 or <4000 range? My concern is to do all this work and AGAIN end up with the power profile of a high CR small displacement turbo motor (not a nice linear curve), even if it's 100hp/400whp old low/high vs 200hp/800hp new low/high. Rao has his LS1 bimmer blown, making something like 550ftlb tq at 2500rpm...

http://imageshack.us/photo/my-images...dynopull1.jpg/

very appealing for the street, but would have to be done with turbo(s), as the SC pulley would stick up 6" through the hood
Something a hair more upper-rpm biased would be preferred, but not too much...


Things I consider: EVOs and STIs with their low CRs and displacements are dogs out of boost. My LS1 will be stock compression ratio, with E85 and intercooling to suppress knock. If it proves to be a problem, I'll swap heads and lower CR a point. But for the mean time, v8 power down low... I don't know what that's like. Am I a fool for trying to get a turbo to be producing 10psi at 2500rpms with unassisted WOT?

It looks like I need to bother the locals and get rides...

Sarg

iTrader: (6)

Get a 3000 or 3500 rpm stall

ClimberD

I edited that post some more after you posted.

The 5eat is, stock It's a seriously stout converter. Frankster with the 3.8 GN, turbo hx35w swap just commented he would prefer stock, but he's also making full boost in neutral with that little 30R-sized turbo

Sarg

iTrader: (6)

Well there ya go, what are you worried about 2500 for, lol.

ClimberD

I've never had enough low-end grunt to see that 3500 do anything. VF40 stage 2 would just rip right through it, and my current TD06-20G doesn't touch it in 1st/2nd gear. I'm sure I can get it to spool with brake boosting, but the point is to not have to do that. On a dyno in 3rd, I'm after that 2500 spool target (10psi is a bit ambitious), because on the street in 1st gear it's going to be substantially later boost threshold.

BTW fun fact why turbos spool later in lower gears: it's a function of time, not load. Log time and MAP, and notice the same time duration to gain target boost, whether in 1st or 5th. If it's .5 seconds, it's a couple thousand RPM in 1st gear, or in the same .5 seconds, it's a few hundred RPM in 5th. Which is why small turbos are so nice, since there IS enough energy to spin bigger ones, just takes a little longer... of course small turbos are terrible up top... yeah, I'm back to square 1.

ClimberD

Oops, Rao's LS1 isn't. It's a 6.6 LS2 with L98 heads and L76 intake, cable throttle, LS1 electronics. Just a tad more displacement than 5.7

But 10.4 CR with 10psi appears fine, assuming pump gas.

ClimberD

Maybe you guys have a solution to the last problem of this build:

In stock form, the steering rack sits directly below the torque converter bellhousing. I need to lower the engine/transmission a lot, which means the original location of the steering rack will be filled with torque converter. I can either move the steering rack 4" down, or 4" forward via GTO pan, and then it will clear. Trouble is either option will kill suspension geometry.

Do you guys know of offset steering rack solutions or ways around this kind of problem?

ClimberD

Great work and documentation Timmmy http://www.motorgeek.com/viewtopic.php?p=547028#p547028

timmmy

Thanks

Progress has been slowed a little by the recent Northeast snowstorm killing my power for a week, that and lots of day job work to be done.

I should be back into it this coming week though, and hope to have it buttoned up in 2-3 weeks, just in time for more snow, so its a good job its AWD

I ended up going with http://www.psiconversion.com/ for a new harness custom built for the LS1 with LS2 intake and DBW, they did a great job and I have the ECU from them in the car and the harness partially installed.

Now I need to make a final decision on which cam setup to put i the motor and things can get buttoned up.

Cheers

H

zach914v8

I know this is an old thread, Im sorry I had to open it back up. But did anyone figure out if the ls4 crank pulley would fit? did the timing cover have to be modded? results? I am doing a v8 porsche 914, and space is very, very tight.