# Project Cheap, fast and reliable (?)



## Laurelturbo (Dec 12, 2009)

Hi there,

since this is actually the second thread on this car, I feel some quick, basic background info is needed, before posting my new build. If you dont care, get bored, or just want to read on the new L24 tuning, jump to the next post.

In the next post I will show all my tuning, ideas and so on, with ignition tables and all.

About 1 year ago, I claimed I could build a fast reliable car for less then 2000$. The car was a Nissan Laurel with a L24E engine. Thanks to some smart buying, I managed to do 0-100mph in 10.4 seconds with normal street tires... On a slightly wet day!

Heres the wet info on the old setup:

Nissan Laurel 1987 model - ugly as hell
L24E 
Stock internals
HKS 2mm steel head gasket
~8:1 CR
T04E China copy turbo
Stock L28ET manifold
Stock inlet manifold with 50mm throttle body
Megasquirt II
Single coil
NGK XXX9 plugs
444 Supra injectors @ 100% DC
Walbro 255L\h fuel pump
Dual stock fuel filters and 2 fuel rail pressure points
Stock tranny
Performance Clutch of unknown brand
Welded rear axle
215mm 17" tires

Otherwise stock.

Measured performance (speedometer readings with camera):
0-60 : 5.5 sec with insane wheelspin
0-100mph: 10.4secs

Outperformed cars:
S13s
280bhp SR20DET 240SX
2 more 240SX
A horde of Audis
Another Audi (sorry, but I hate them, and plan to outrun them all).

Engine info:

This engine is bulletproof. Im serious. Ive never ever heard suck extreme knock as I did during the tuning of this engine. It sounded like the piston knocked in the asphalt. this is said to be because cooling on cylinder #5 is very poor.. Water injection and a lower AFR took most of it away though.

The power band is interesting. This china copy turbo is not exactly Garrett performance, but with the .63 exhoust house with a high stage wheel (Stage III I think), it spools 25 PSI ~4000RPM, and holds it all the way to the limit at 6550RPM. Id say the power peaks approx 5500, but it feels rather strong up to redline. Lower end power is great though, the L24E is strong from 1000RPMs, with its original 180NM of torque coming in at 2000RPM, now boosted by 5 PSI from 1800-3000 where it starts to rise. 

To be honest, I never though it could work. I set the wastegate at 18 PSI, and started tuning. When I increased it to 25, I thought NO WAY, but yet, 5000miles later, the engine is still in good condition. The cheap turbo though is dead.


Here are some quick pics, followed by the new build plan:


























































Heres some pics form the initial build, the car was bought with a broken engine.






































Previous owner tried turbocharging with stock FI system. BAD IDEA! Oh, and note the tiny forged stock con rod!









Stock ECU out...









Some wireing









More endless wiring









voila


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## Laurelturbo (Dec 12, 2009)

Lets fix, and anonyminize the engine bay:









New, bone stock donor engine









Cleaned up and with a new gasket:









Wiring 






































30-1 - Black edition 









the whole car is black edition, even the FPR is black matt



















How to: VR sensor install the budget way


















Crazy norwegians




















Next: The new build.


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## Laurelturbo (Dec 12, 2009)

*The new build:*

So, with the turbo dead and all, I figured I either had to scrap the car, of build a new engine. My vote landed on the second option. So here is my plan, and pictures of whats already done. The advanced geeky stuff follows below.

Car:
Stock, the Laurel is quite good. Its actually a 4 door version of the R30/R31 Skylines! The chassi is great, handling is good, and despite the fact that the longest engine in the world hangs in the front, the car feels balanced, and great to drive. Upgrades is always welcome though, so, since this is a budget build, some cheap JC-project coilovers was installed! 










These are S13 parts, but Nissan is Nissan, so i only had to drill 1 hole, and the rest was bolt on. Also hubs and brakes are upgraded to S13 in the front.










The install is so fresh, I dont have pics yet! They will come!


Driveline: 

The rear axle must die at some point. The weld is strong, but the strain on the driveshafts and wheel bearings is HUGE. But I wont do anything until they fail me, and I hope they can handle a little more power.

The tranny is due for a change. 1 gear cant handle the torque, and jumps out of the gear if I strain it, probably a bad bearing. A S13 tranny is on its way.

Engine:
Now to the interesting part. Now, I now some will disagree, but I will keep the L24, not L28, 3.1 L or anything. It is final, and you cant change my mind: This is why:

Power reduction: I will bend the chassi with more power
Cost: They are cheap (free often)
L24s are easy to get here, L28s ARE NOT
RPM: Im hoping to get power up to 7000-7500 RPMs.

Now when thats over, lets discuss the details in a list:

Internals: Stock. If they can handle estimated 350FHP with knock, they can handle 420 without.

Clutch: Sinter upgrade

Cyl head: N47, mild porting and modified for better cooling









Inlet manifold: Considering to make a new one, if not, STOCK

Throttle body: 50mm is to small. 60mm is more then enough though.

Cams: Now it gets interesting. 

CURRENT(stock) NEW
Lift @.050 ~.410 .502 intake, .492 ex
Duration 215/215 230/226
Lobe seperation ????? 114

This is a Custom grind by Schneider cams, and comes with a set of dual heavy duty springs and retainers. The hope is to get good lower end power, with desent top end power. I am considering some more duration though.

Turbo:
Ive done so much research, and calculated air flow and turbo charts and so on. The winner is the legendary T04E 50 trim with a .63 stage III or V wheel. It could overspin at high RPMs, but I think Ill be alright with some more CR.

CR:
Stock is 8.5, and with the new gasket I suspect about 8:1. Now some say "great", but I would like more, espescially with that hotter cam. Im thinking of shaving the head to achive about 9:1 - 9.5:1 CRs. This will increase off boost performance, compansate som for the wilder camshaft, and give more power all the way. 

Fuel system: dual fuel lines, bigger injectors. Maybe E85. 

Ignition system: Im currently using .2mm clearing on the spark plugs, and still I have problems at high rpms. I think a COP, or DIS coil system must be installed, but I have not yet decided what system to install. 

Water injection: I installed it to improve performance, and stop the knocking. I used a stock injector strapped on the inlet pipe. Water pressure comes from a Peugeot head light washer engine, pumping 75PSI!! I use washer fluid from the windshield washer reservoir. Megasquirt activated at ~4300RPM AND 230KPA+

Tuning:
Many opinions here, I know. Here is my experience with tuning the L engine:

They like richer AFRs, probably because of cooling problems that give knock
They cant handle much ignition timing under boost (table follows)
They can handle impressively much timing for a old 2 valve engine (off boost)
They love the timing coming fast and hard
They knock for nothing under boost, but you must be deaf If you dont hear it
Nothing kills them.

My tuning:
I first tuned the car without water injection. I had rich AFR, and little timing to find a way around the knocking, but with water injection on, things turned to the better, and I actually increased ignition timing with ~6 degrees!! As you can see on my timing table here, I got relatively much timing fast. The car has great low end torque, and AFR table shows the general idea, but far from the facts.




















You can see when the water comes in, the timing goes sky high. 

With the new setup, Less boost can be used because of the higher CRs. I hope this will allow some more timing (and lower EGTs). I guess 20PSI should make this car a rocket. Ill need some more fuel though, dual fuel lines and so on. 

Well thats my car. ~4000$ total cost is the goal, and hopefully not to many cars can keep up.. Im aiming for reliability as well, but Im worried about that rear axle..

Power goals is to get close to 400 flywheel hp, but more important, a good powerband. I expect the torque to be about the same, peaking at about 4000RPM. I will dyno it at some point, but it probably wont be before spring time, or even summer. 

Build time estimate: 4 months.


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## JNCoRacer (Apr 18, 2003)

Man, I'm jealous. How much to ship that car to the US? Hahaha.


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## Laurelturbo (Dec 12, 2009)

Haha.. Well, If you pay good attention here, you can probably build it for less


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## JNCoRacer (Apr 18, 2003)

Well we dont have those cars here in the States. The closest thing we have is the 1st or 2nd generation Maxima, with L24 or L28. Its kind of hard to find one in good shape these days.


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## Laurelturbo (Dec 12, 2009)

Im doing lots of research here. Now, to make this huge power on stock pistons, cooling will be essential. So Ill need to design a better water injection system, Im just not shure how to do it without using big $.. I am thinking of following my current tactic, with 100% dutycycle on the injector, and activating it at high KPA\RPM levels, but I would like to have water at lower pressures as well.. 

Option A: Dual injection, one small injector, and one big. I could go for the biggest possible injector as primary, and add a secondary injector thats much smaller, and can work at lower KPAs... It will be rather complicated though, and it will use 2 output ports on the already high strung Megasquirt ECU...

Option B: Pressure regulation, possibly through some sort of PWM pressure regulator.. Dont know what valve I could use though.. 

Option C: PWM injection with several injectors spaced apart. Engeneerworks though.. 

Any good inputs here? And keep in mind, Im not buying aquamist or something for 400$, if I wanted an expensive car, Id buy a R35 and be done with it 




Id also like to share my turbo choice, I wont type my A4 sheet with formulas and equations, but I figure Ill need approx 50LB/min of air for my power goals at high RPMs, and about ~2.6 in pressure ratio. Heres a 50trim T04E:

never mind the yellow lines though, theire not mine









A trained eye can see from this that Ill have a veeery good mid range efficency, and even though it drops a little at redline, its not more than 10% or so, and I dont think the heat created will be enough to argue for a bigger turbo.. After all, turbo lag is the enemy here, I want full boost before 4000. I think chanse for surge is very low too, so I hope this is a good choice for my engine.


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## chimmike (Oct 17, 2002)

i think dual injectors/cylinder will add unnecessary complication in tuning and probably not cool as well as you think. IMO water injection is a simpler, cheaper, and likely more effective way to cool the combustion chamber. If you plan on road racing this car, you may want to consider a larger turbo that is more efficient at redline, simply because you'll spend more time in higher rpm than just regular street driving. 

sweet project though, and you've done some good research.


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## Laurelturbo (Dec 12, 2009)

chimmike said:


> i think dual injectors/cylinder will add unnecessary complication in tuning and probably not cool as well as you think. IMO water injection is a simpler, cheaper, and likely more effective way to cool the combustion chamber. If you plan on road racing this car, you may want to consider a larger turbo that is more efficient at redline, simply because you'll spend more time in higher rpm than just regular street driving.
> 
> sweet project though, and you've done some good research.



IMO?

About the turbo size, you could be right, Im scared the 50trim will be a bit too small, on the other hand, there are so many out there who claim way above 400hp on it, and my numbers are a bit strict, Ive used rater low efficency, and high BSFC, dont remember 100%, but about 90% and .65 I think. I wont afford a turbo until january, but I shure will think hard about this. The BB T04E is a VERY good match for my engine........

Any other suggestion on a turbo by the way? Its hard to find a turbo with journal bearing, that compare with T04Es air flow/pressure capability and price..


Why journal bearing you say? Simple, I buy this turbo now, and I can have it for 20 years, with 50$ overhauls. A GT turbo is almost twice the price, and I just dont think its worth it.


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## chimmike (Oct 17, 2002)

t04e's are an old wheel and housing design. If you can afford a newer design turbo you'll be happier. Borg Warner's latest turbos, while journal bearing, have incredible response and efficiency, and cost a fraction of what the garrett GT turbos run. I'm a fan of turbonetics turbos, too. 

IMO=in my opinion.

If you really, honestly will be road racing the car, a larger turbo may suit you better. You can make little changes here and there to affect spool, but for a few hundred rpm later spool with better top end efficiency, it'll be better for the engine.


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## Laurelturbo (Dec 12, 2009)

Where can I find borg warner turbos cheap? I did some searching, but found very little.. 

The car is intended for track days, and road racing. Though I agree bigger is often better, we should keep in mind that 7000RPM is absolute redline.. Also, in twisty circuits, you spend quite more time in the 3500-6000, and above 6000 is generally only on straights, and fast circuits, and of course highway "racing".. 

Thats the philosphy of my turbo choice, T04E. Strong mid range, producing the least possible heat, yet not surging. 

Ill do the calculations again here, keeping first with high hp, then moore realistic to my goal, though with no real numbers to stick to,its what I expect.

The numbers:
HP: 420
displacement: 146
RPM: 7000, but expect max hp @ 6500
Conditions: Sea level and max 77 degrees F
Voumetric efficency: with higher comp levels, new camshaft, est max 95%
Intake manifold pressure: Never seen abovee 122F
AF: Due to the water injection, Im aiming for approx 12, Ill never get to measure it. 
BSFC= though 2valve, with water injection, I guess .60.

Airflow = HP * AF * BSFC / 60
= 420 * 12 * 0.6 / 60
= *50.4*

Now increasing to 0.55 BSFC we got *46* , so this all comes down to making the engine efficient.. And thats not always easy, but water injection and higher CRs should hell a lot!

Now for the pressure ratio = (air flow *639.6 * (460 + 72)) / (VE *(RPM/2) * 146)

= 17141467 / 427050 = 40

Boost required is 40-15 = 25PSI

Now for the actual ratio. Ill estimate about 2-3 PSI to drop through the pipes, throttle body etc, so pressure is now 43 PSI

Now in the inlet of the turbo, theres a large air filter that should not be a big obstruction and cause any big loss. Typical values are claimed to be 1PSI, I dare to claim 0.5 since theres only a 3" pipe 3" long to the filter itselfe. 

The pressure ratio is pressure (43PSI) / inlet pressure (14.7-0.5) = 43/14.2 = 3. 

Now this is interesting. With the 50.4 air flow required @ that high pressure ratio, the T04E comes in short. Wit 46 though, and a more efficent engine, I just could manage it, though its on the limit. 

Conclusion: I think I indeed need a bigger turbo for this hp goal. But this is a best case scenario. 420 FWHP is optimistic at best, and reducing it to more realistic 380 gives these numbers: 

Air flow : 46
Pressure= 37 
Boost= 22 PSI
Pressure ratio: 2.8 

This is within the compressors ability, and should make this 2800LBS car into a true killer, offering great spool up, strong mid-RPM and without producing to much heat at redline. I honestly expect the power to rise far up the RPMs with the T04E, and, though the top power can be raised with a larger turbo, the all important mid range and spool up will suffer. A GT turbo could do even better, yes, but I find it too expensive, adding 50% to the price..



Oh, quick side note, I have no personal experience with turbonetics, but I know some who does, and they are NOT impressed. Even a local turbo store claims they are no good, so I wont buy one.


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## JNCoRacer (Apr 18, 2003)

I never had any problems from Turbonetics. Had a T3/04E hybrid.


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## chimmike (Oct 17, 2002)

had 25k trouble free miles on a 60-1 on my 350z (turbonetics turbo)

regardless, I also think that a larger turbo running at a lower boost level will be more responsive and take less time to reach max boost.


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## Laurelturbo (Dec 12, 2009)

chimmike said:


> had 25k trouble free miles on a 60-1 on my 350z (turbonetics turbo)
> 
> regardless, I also think that a larger turbo running at a lower boost level will be more responsive and take less time to reach max boost.


Yea, I hear both stories, but I think Ill stick to Garrett. Hard to find turbomaps to turbonetics as well..

Regarding that bigger turbo with lower boost, I wonder how you want to do that without more displacement, wilder cams and so on. Now this can be done, shure, but thats not cheap.. And yes, upgraded exhaust AR and wheels can help, but it will move the powerband to much for my setup.. Mid range is very important if I want power when changing gears.. 


I am unshure of the AR though. The initial thought was .63 with a high spec wheel (lower resistance), either III or V. Any experinces on these turbos would be great, pleace add your setup with it..


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## chimmike (Oct 17, 2002)

always want a stage V wheel, IMO. a .63 would be good I'd say, without losing breathability up top.


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## Laurelturbo (Dec 12, 2009)

I think the turbo is chosen. 

Now to the ignition system. I was thinking of using some RB, or SR coils, but when I tried a SR coil on the engine, I started thinking about the cooling of the coils.. I dont think they will like a 60 degree angle, and probably would burn if I tried...

So Ill need a coil pack. If anyone has a good suggestion on cheap and/or good coilpacks, scream out. 

If not I will probably use something from a ~2000 Mitsubishi etc that is easy to get here in Norway.


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## chimmike (Oct 17, 2002)

I'm not sure what kind of engine management you'll be using, but the electro-motive TecII and III use mostly GM stuff, GM coils, sensors, etc. Pretty cheap stuff to get any easy to find, I'd imagine easy to find even for you in the Norway-lando.


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## Laurelturbo (Dec 12, 2009)

Im using megasquirt, so I can run whatever I want. 

The problem though is that Norwegian car-taxes are extreme, the cheapest car in Norway is Hyundai i30, costing about 25.000 $!! 

A 3.0 BMW is about 100.000$!! 

My point is, almost everyone with newer cars have max 2 liter engines, so 6cyl coils are hard to find.. I was thinking of 3 "DIS" coils or something, but Im not shure how beefy a coil from a 30hp/cyl is... 

I guess Ill stumble across something at some point...


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## chimmike (Oct 17, 2002)

well, I'd say try to purchase them used on the internet. Should at least be cheaper that way even with taxes


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