[swiftboost]

This turbo build was done about 2 years back -

It had just been a few months that I moved to my new apartment . My kids found new friends to play with in the neighbourhood. Soon I made friends with a family at my church ( kids already knew their kids by then). There were a lot of things in common, most importantly love for automobiles. He had some parts for a turbo build but dint quite get the time or patience to put it together. Soon (in early 2008) we decided to do a M800 carb turbo build with as little as performance parts possible and a shoe-string budget. We would meet up and spend time on the build almost every evening.

This was an old 86-87 beaten up M800 with quite a bit of rust all around. We decided to go with the 800 engine as-is without a rebuild to see how much of boost it could withstand and later maybe based on the results do a fresh rebuild. My friend also had a NOS kit he had used in the past but decided against using it along with turbo build.

1st Turbo set up

1. Small Daihatsu turbo (used)
2. AISAN Carburettor
3. Greddy (knock off) BOV
4. Ambassador MPFI fuel pump
5. DIY MS turbo manifold
6. MS - 2 inch exhaust
7. Small Hyundai intercooler
8. An Industrial pressure (vac/boost) guage
9. MS - intake plumbing
10. MS - Carb intake collector hat
11. Radiator hose quality rubber hoses*

About 2 weeks into the build we had the setup ready. I wondered how this carb would behave when boosted (the stock carb would tend to bleed from everywhere). With a few adjustment to the carb, the car started and idled fine. Took it out for the 1st test drive and soon enough faced the 1st problem – car would fall flat on its face by the time it reached 2-3psi, as though it just dint get enough fuel. The good part was that the carb was not leaking fuel from anywhere. Found some info on a similar carb and tried replumbing the vaccum and boost lines. It showed a lot of improvement and things were fine till about 7-8psi. After a few permutation and combination on jets the car was good for 10 psi, after which the fuel compensation was weak and we had not way to retard the ignition timing. Now, we had our next problem – oil being spit out through the breather pipe (partly maybe because of worn out engine/ blow by).

2nd setup

The same as 1st setup except for a fresh engine rebuild. No more spitting oil through the breather pipe. The car/engine felt much stronger and crisper than before and with further refinement to carburation the car was feeling quite strong till 12-13 psi. Soon we blew an intake rubber hose, which was replaced by a better one. On one of evening test drives on a then vacant air port link road things suddenly took a bad turn. While on boost (peaking around 14 psi) a sudden mettalic noise as though something broke free !! Quickly turned off the ignition and rolled to a halt on the road side. Had a bad feeling – wondering if the piston or con-rod broke/bend. Opened out the spark plugs to see all plugs in OK condition. Took the plug wires out and cranked the car – surprisingly, no mettalic noise. The car engine seemed to be OK. Plugged in the spark plug wires and the car cranked up and idled just fine. Just as we drove the car, got a weird feelin – NO BOOST !! Stopped the car again and upon close inspection, found a blown turbo, litterally !!! The turbo - compressor side had a narrow long crack and the compressor blade broke free through that. The shaft remaining intact in the compressor housing. Lol – No compressor blade / No BOOST !!!
Luckily we had another of the same turbo that we had picked for parts. Marked out the positions for the entire assembly, opened the turbo, swapped in the compressor wheel and slapped it back together according the positions earlier marked, hoping we would get it as close as possible. Wanted to get it balanced after this, but had no clue where to get it done though. The car ran just fine but we ran into turbo issues again with a failed turbo – oil in the intake pipe (most likely because of the DIY rebuild)

3rd setup

Now we had a slightly bigger KKK turbo, a bigger carb collector hat and a top mounted intercooler with shorter intake plumbing as compared to before. With this the car felt stronger on boost. But the main issue this far has been to get the fueling right on higher boost. I was out of town on a weekend with my family and on the Monday morning, he called me to say that a piston broke. Hmmm … Maybe another engine redo, I thought !!
In the evening he told me that while I was out of town he had used NOS while on 12-13 psi on 2 gear, which is something I had told would likely happen with NOS turbo combo on a normal M800 internals. Having said that – I should say that the humble M800/ internals can take some beating !! The next day we had the engine out to see what/what all went wrong inside. To my surprise, it was not much. The top ring land (about 1/5th of the dia had broken).

4th setup (last thus far)

It was about 6 months into our build by now, learning more - as failures, lack of success and days pass by. Got a NIKKI carb and this time used a slightly dished out/ low comp pistons for the new build. Again, had to spend sometime to get on the learning curve for the new carb but definitely quicker than last time. The result with lower comp pistons and the new carb was – the engine felt stronger on boost and reduced pinging after it was pushed beyond 14 psi. We did not have anything in place to retard ignition timing with boost/load and that has been an issue right from the time we crossed about 7 psi boost.




Besides all the above engine mods, we also changed the M-800 gear box to a M-1000 gearbox and a few mods on that. Stock shox were rebuild for a stiffer suspension. A slightly modded clutch and brake booster was also installed. We also put in a recalibrated esteem speedo console into the M-800 dash board. After all this I can say that the car felt quick and fun/scary as hell to drive.

The car is still far from perfect especially on high boost (above 10psi) fueling and ignition, but it was a lot of fun and a whole lot of learning. I wish I knew carbs well to make it behave better !!!

Next plan (don’t know when) - To make the same setup MPFi. Atleast, theres a lot more predictabililty in fueling and ignition with a piggyback/stand alone ECU.

[pramodkumar]

Originally Posted by swiftboost

This turbo build was done about 2 years back -

Glued to this thread, please post some pics of the setup, especially the plumbing details, just a question, did the ambassador MPFI pump solve the fueling issues?

Originally Posted by swiftboost

To make the same setup MPFi. Atleast, theres a lot more predictabililty in fueling and ignition with a piggyback/stand alone ECU.

i like things the old school way, and DIY is more fun when you dont need hitech tuning equipment. but tuning a MPFI car for a turbo setup is easier than a carb if you have the right expertise.

Pramod

[jatinpatel]

Awesome awesome awesome thread, I am so totally glued to it, Please share some pics of the same.

[swiftboost]

The ambassador fuel pump was more of a pre-requisite for the turbo-car to function as a blow-through turbo setup. The carb fuel pump was a relatively low pressure pump that fails to pump enough fuel (especially on high boost)

This project was done about 2 yrs back and dint think of taking pics then. I guess I should have taken a few snaps.

Comparison - Aisan Vs Nikki carb

[pranavt]

Respect to you guys. Not many have the stones to attempt an air-filter change. let alone a whole turbo build. I do not know anything about carbs, but I'm pretty sure you can do alcohol injection and keep your ignition curves and gain a few octane levels. Do 50/50 water+meth injection and you will see IATs enough to boost even more. Don't know the strength of the block so cannot further much about that either. Can you upload some pics of the engine internals?

Again, massive respect to you guys, the scene needs more people like you.

[swiftboost]

This was not meant to be a serious drag machine, just a fun thing that we did. Theres a small problem with water/ alchy injection - It cannot be done before the turbo (theres a good chance that the droplets eventually eat up the compressor blades). So, it has to be done after the turbo which needs a high pressure pump (also needed for good atomization) and one would also need a good controller for the same. And the need for all this makes it quite complicated and expensive. But, if done properly, it should give some amazing result on a trubo car.

[pranavt]

As long as the mist is fine enough, the compressor blades will be fine. People have been running such configurations for a long time now, and successfully. A smaller flowing nozzle will have better atomization anyways, which will be suitable for the motor. I understand it wasn't an all-out drag machine, that makes it more impressive. A DIY water+meth injection setup can be done in less than 5K INR and will give you power and better reliability.

[swiftboost]

I had tried my hands at basic water injection during the late 90's based on what I had read up in some old article (can't literally call it injection though). A basic set up working on a carb M 800 - Used a surgical needle connected to the vaccum plumbing and the supply was directly proportional to the vaccum. It was not quite effective after part throttle and WOT (low vaccum situations).

I have always wanted to do it on my turbo Baleno and maybe get the RD ECU to control the injection and have a separate map for it (provided Karthik helps me with a extra map table). I got to tell you, Karthik has helped me with lot of one off things in the past. Including upgrading my old RD ECU to the new RD 901.

[techn0l0gist]

Hi Swiftboost,

Give this a try, would make your car run better:

- Get a Maruti 800 mpfi fuel pump and install it - also make sure you use the fuel lines and fuel filter from the mpfi 800.
- Use a mallory 4307m fuel pressure regulator and connect a hose from the "reference port" of the FPR to a place on your carb that sees boost. (the FPR is a 1:1 FPR, so when your boost increases by 1 Psi , so does your fuel pressure, and with a MPFi 800 fuel pump, your carb would keep working properly as the boost increases)
- I'm not sure how the nikki carb works, but in case of the mikuni carb that you can jet the primary and secondary(you can find the jets easily on JC Road - no need to drill stock ones) so that the secondary opens on boost and makes the car run at richer AFR and the primary is used when not boosting (you will need to make a mechanical linkage for opening the secondary butterfly and remove the vaccum actuated secondary) , at what point to make the "transition" needs a fair bit of trial and error.
- For the carb hat - the one from the gypsy works just fine (esp on the mikuni carb)
- Since you have no fuel leakage problems in the carb I believe you have sorted them out somehow but a nice method is an "air-seal" as described in the book "turbochargers by hugh mcinnes")

- For the timing, I'm not sure if there is a perfect way of this other than a standalone ignition controller - please do let me know if you have found some way, you can always turn to distributor to a very low initial value - but then the engine does not run right off idle .

Hope that helps, just my 0.2 paisa from what i've learnt so far from my own experiments with turbos and carbs

[swiftboost]

Hi Technologist,

Thanks for the handy tips and parts info. We really wanted to do the turbo 800 on a shoe string budget with commonly available parts/accessories. Im not very good with carbs and had a lot of problems to get the tuning right (acceptable levels). Another half baked approach we tested was to have a variable (stepped) voltage power supply for the fuel pump. That gave us a lot of flexibility in tuning, especially on boost.

I believe there are a few after market guys who sell such solutions like DAP. Later also got to know that some OEM fuel injection setup also function in a similar way based on load and other factors.

[swiftboost]

Few pics taken a while after the turbo failure. At this point of the build we had the Aisan carb. You can also see the basic turbo manifold with the turbo hotside on it (with some rust - being out of action for a while). The adapter flange for the turbo has two sets of bolt pattern to swap the old and new turbo quickly. Just in case one fails the other one can be kept ready. lol !!!

This is the pic of the broken piston (ring land broke free with NOS on 2nd gear pull)

You can also see the industrial/ basic turbo boost/vac gauge.

[Psycho]

Well the carbs run best at 7psi of fuel pressure and not beyond and as the boost increases you need to evenly increase the fuel pressure.Another point to look out for is that beyond a certain point of pressure the float in carb could collapse due to the pressure.

Logically on the ignition advance / retard the timing on the car can still be controlled by the vacuum advance on the distributor as any boost would retard the timing accordingly, if the knocking continues it would be better to retard the distributor further.

Water injection on carbs can work if injected in a fine spray before the turbo intake but it can damage the blades on the long run, easy trick window washer spraying on to a foam filter.

The ring land crack is due to a severe knock, lack of fueling am assuming that you guys used a dry nos setup.

But overall amazing build and great learning experience paying off on the turbo baleno.

[swiftboost]

Hi Psycho,

I subscribe to your thoughts. The car performed quite well till 8-10 psi and the further aways from this level created more issues with both fueling and ignition.
I guessed as much about the severe knock part with NOS (ring land failure).

Baleno was pretty straight forward and relatively easy as compared to this 800. I already had the turbo and its manifold - just had to machine out an adapter plate. A 3 inch dump pipe, rest - 2.5 inch exhaust. About 10 days of work and it was on the road with the RD ECU. Dint have much of a problem with fueling and ignition when compared to the 800 carb setup.

[santsharan]

WOW ! What an interesting thread. Hoping more technical discussions here. Already subscribed to this one.

@ swiftboost, please share the total expenditure on this project.

[IronWolf]

SB, I thought the DIY 800 boost job was impressive then I see you have TCed a road worthy and reliable Baleno.

Which part of Bangalore are you? I feel the need to stalk you and see these two creations.

Originally Posted by swiftboost

Baleno was pretty straight forward and relatively easy as compared to this 800. .....

Dint have much of a problem with fueling and ignition when compared to the 800 carb setup.