81280zxtc

Fellow Z buffs. The shop where my Z is being worked on finally finished the fuel system, and it was dyno time. Here are the results:

1st run: 1.2 bar. 237hp / 243 lb/ft torque
2nd run: 18lbs boost 284 hp / 282 lb/ft torque
3rd run: 21lbs boost 315hp / 310 lb/ft torque

That was it for Saturday.

Should I be estatic?

After all the mods, I thought I would be somewhere around 400hp, but I guess I'll settle for what I have.

The tuning was done on 112 octane race gas. The Haltech was on the money with the exhaust. Clean, no lean or rich condition.

I wanted to try bumping the boost to at least 25lbs, maybe 28 once I get the EVC dialed in right.

Any advice?

I do have a HKS metal head gasket, and ARP head bolts, so I'm not worried about having a little too much, but I don't want to break anything.

What to do?

Thanks to all who will reply..

Rob

Heat Rave R

What kind of mods do you have? Otherwise, those sound like impressive numbers to me.

81280zxtc

This is what I can remember

Haltech E6K enging management, Turbonetics T60-1 Ceramic Ball Bearing Turbo, Cartech Intercooler & blow off valve, 12 injectors 6 primary-6 secondary staged, mild port and polish head, TEP throttle body, HKS cam, MSD 7AL2 Ignition amp w/ MSD 8251 ignition coil, Aeromotive fuelpump, fuel pressure regulator w/ 2 direct feeds to injector rail w/ seperate returns, HKS EVC Pro, Tial 38mm wastegate w/ 1 bar spring, 3" downpipe into 2.5" HKS exhaust

I think that's it..

lww

I would change your 3" downpipe to a 2.5" downpipe and see what happens. You're not gaining anything from going through a 3" pipe to a 2.5" pipe but turbulence. The exhaust gas has lower pressure and is moving slower through the wider 3" pipe, then it gets constricted at the joint increasing pressure and accelerates into the 2.5" pipe. Where the two come together is going to create turbulence and back pressure up to the exhaust turbine.

How long is your downpipe before it joins the 2.5" pipe?

Smooth transitions are as important as free flow.

Bleach

Nice setup! that's not your average 280ZX turbo!

81280zxtc

The 3" extension comes from the turbo outlet down and around and stops right where the cat would be... I don't have a reference point under the chassis for you. Sorry.

Bleach

...or continue a 3" pipe all the way out the back!

Skully

3" is recommended all the way out, especially with high numbers you are running...i dont understand why you have a bigger pipe going to a smaller pipe...usualy its opposite...as ive heard it "speeds" up the flow by funneling the exhaust.

assimilated420

absolutely...the vibrations on the pipe help flow the air and sound, and if you have hit a wall it bounces the vibrations back against the constant flow..so it messes things up..(kinda like the lil noise makers on the back of them wind-up rice burners!!)go at least 3" straight back and if you dont have all that many sound restrictive laws and such...why not just rip off the muffler and run a straight pipe...thatll give ya a lil extra hp..

apollo

nice . . . .now only if i can produce that kind of power on a student budget

81280zxtc

The tuner had some questions that maybe you guys could help answer:

1) What would / is the max RPM range for this motor?
2) What would be max boost level for this engine?
3) How much timing can it hold / run w/ 22 lbs of boost or higher?
4) Does the factory intake have enough flow to support higher than stock HP numbers, or is there an aftermarket substitute?

If I could get some help with these answers, he could tune it more aggressively vs conservatively.

Thanks in advance.

Bleach

1) The stock cam flows well to 5200 rpm just like the non-turbo. Redline is about 6400 rpm.
2) 22psi or so. About 380 crank hp or 350 whp is typically considered the max power on the stock engine setup. (block/head)
3) depends on your fuel and intercooler. As long as it doesn't ping...
4) yes, the stock manifold can support higher than stock numbers. You're running 110hp more than stock at the wheels. There are no mass-produced intake manifolds for this engine. Some people make a manifold for themselves.

lifegrddude

1. Depends on internals and all that stuff, but on a stock block 6500 revs is the most you'll want to push.

2. Max boost is sort of a gray area since it'll vary from car to car. From what I've seen, the most people have pushed on a stock motor is 18psi, but there are some that cranked 20 through the block. I don't know how reliable or long their motors went.

3. I can't really help you with the timing question since I'm only pushing a max of 11.5 psi.

4. The factory intake, with some mild porting can flow well enough for 400hp, but I'm sure a custom fabbed one will do better. As far as I know, no one is offering an aftermarket bolt on intake manifold for an L28.

John 82ZXT

lww

Yikes! He's probably a good guy, and even more so for not claiming to know more than he does as this is a common cause of failures in 'built' motors, but you may want to get him in touch with someone who has a little more experience with L series motors to help with these questions.

As has been mentioned by others, every motor is different and in an L6 the length of the crank dramatically changes the dynamics of the internals. At high revs, the rotating mass will put an incredible amount of stress on the crank shaft that will greatly reduce it's life expectancy.

1) For reliability, I wouldn't go with anything over 6800 rpm and probably wouldn't go that high until I saw the dyno hp/tq curves to see where the power begins to flatten/fall off.

2) Again, it depends on your engine, but for reliability and stock internals, I wouldn't go over 15 to 18psi. I'm running 25psi but I've got a forged crank, forged pistons, and o-ringed head.

3) It can handle as much as you can put into it without pre-detonation.

4) The factory intake will flow over 400hp.

Again, I would also change your exhaust out to a 3" mandrel bent all the way out or change your down pipe to a 2.5" to match your exhaust pipe.

Good luck!

81280zxtc

I've been trying to get in touch with Corky Bell, who originally built this car about 15 plus years ago when he was Texas Turbo. I have tried contacting him at his new company, BEGi, but no luck. The car originally had the Haltech F3 set up piggybacked to the stock ecu. It went back down to Texas for the 2nd injector set up and was waiting for Haltech to come up with the program for the 2nd set of injectors, but that never happened. (Story with in a story) As far as trying to get him some help with people familar with L series motors, I'm trying to reach out to my fellow Z community for answers and help with this project. I don't have one particular person that I know well enough to speak with, but if anyone wants to contact him with some information, you can call Ralphy @ DRT Inc. 718-397-8586.

Ralphy and I have agreed to leave the max rpm @ 6250 to keep it safe. We are going to leave the timing @ 21 / 22 degrees and increase boost to see how the engine reacts. There is enough fuel to support the additional boost, so I'm not worried about a lean condition. The Haltech will retard timing on getting off the gas, so there is some added protection in case of "pinging".

If you're running @ 25 psi, what engine management are you using?..if any? and how much power are you putting out at the rear wheels? Do you have a dyno graph of your engine w/ power output to compare too?

Thanks...

Z1 Performance

the single coil might be cause for some concern....though you would really have to log it to see.

Are you running a knock sensor? Can you post any datalogs?

I've got a somewhat similar setup, though running a T66 internally gated, stock downpipe (have not had a need to go bigger quite honestly), 3 inch exhust, TECII, BIG FMIC, built motor and head.

I'd have to bust out the old dynos of my car, but I hit 405 hp at the wheels on a bone stock turbo motor (stock head, stock bottom end, just ARP studs and an HKS gasket), using a T3/T04 and the TECII.

As for your questions:

1. what head is on the engine? If its the non hydraulic, 7000 rpm is easily attainable
2. boost - no one can say. Boost in and of itself is a meaningless figure quite honestly, as it's relative to the rest of the setup, as well as the turbo that's making it. Gotta log inlet air temps vs boost and see where the turbo and IC combo wants to be. Example - I made the dyno's on my old setup at 21 psi, and it's not quite as "big" as your turbo.

3. timing - see my comments on the single coil. I don't know enough about this piece to say.

4. I have just under 600 hp now at the wheels but run a stock intake manifold....granted, it's only stock on the outside, but the short answer is yes, it can flow enough. My previous setup used a bone stocker.

lww

Triple 44mm Mikuni's and a T4 on a blow-through setup making ~360 rwhp.

As soon as I get it back from paint I'm gonna be doing some additional modifications to the IC and plan to make a few dyno pulls afterwords to check the results.

81280zxtc

Why would you guess that the coil would be a cause? It's not a standard coil, and is connected to an MSD 7 AL2 ignition amp which is giving plenty of spark. The plugs look great when we took them out after a few runs to see how they were running.

The Haltech has a map sensor and an O2 sensor hooked up for readings. I don't think there's a knock sensor installed. The Haltech is programmed to adjust fuel for a excessive lean condition and retard timing when letting off the gas to prevent damage of detonation.

I have received comments / ideas on the power loss, or lack there of because of the exhaust. I have a 3" downpipe connected into a 2 1/2" muffler. The general consensus is to switch to a 3" exhaust straight thru which I will test by disconnecting the downpipe where it meets the exhaust to see if there is a difference in hp. The other idea for loss of power was the stock pop off valve which has since been capped off was the culprit, but it was blocked off and when removed, showed no difference in #'s. The last idea the tuner and I had was that the a/r ratio on the exhaust side of the turbocharger is a little too large and is spooling late in the rpm band, like around 3250-3500 up to 6000-6250 where it's set to stop. I was thinking to try a smaller exhast housing to see if I can get the turbo to spool sooner, around 2300-2500 rpm, so I can get more use of the rpm range of the engine. Forum members have been against that because of the created back pressure the smaller housing will make, leaving me back at square 1, or having the same results as a smaller diameter exhaust. I think this will be a slow step by step process.

I'm curious about where the power band was on the dyno when you tested. I have not seen any dyno sheets that show clear, consice, smooth power. I've seen dyno sheets with mutiple spikes, and erratic power graphs, with big and bigger hp #'s and was discerning to look at. Making power is one thing, making smooth clean power is another, which is my goal.

Thanks for taking the time to answer my questions ,and I see you're from NY...which is a good thing. I'm in the NYC area...if your ever in the city, I would welcome the opportunity to show you the car.

81280zxtc

Uploaded latest dyno results in my album, but don't know how to post it to the forum.

Take a look and I would appreciate your input.

Thanks.

dr. buddha

im doing a simaler turbo setup on mine exept im using webers and a t3. i was wondering what u did with the hole on the uper left side its about the size of a nikel
or maby a pic?

lww

Hole on the upper left side of what?

Attached is an old picture of it sans block with mock-up piping before going into the car.

dr. buddha

on the carbs. theres a littel hole on the top left side.
i like the way you set yours up.mine has pipping all the way around the motter i will take a pic soon.