Hello,

I race in Lemons. If you aren't familiar with LeMons, it's crap can endurance road racing. Basically, you can only spend $500 to buy and prep a car. Safety stuff does not count. If you participate in a race, the judges can de-value your car, essentially giving you more of a budget for upgrades.

We race a 1989 Prelude Si. After sending the #3 rod through the block in the first race, I spent the winter rebuilding a junkyard B20A5. I used pretty generic parts, ebay gasket kits, etc. The cylinders were badly scored, so I went up to +.040 pistons. I also put a huge oil cooler out of a GM truck on the front of the car. The new motor has three races on it (about 36 hours). oil temps never get above 220f.

After the last race, I told the judges I wanted more power so they agreed to let us spend $250 if we put a ill-conceived blower in. See where this is headed? I want to build a blower set up making 6-8 lbs of boost without melting the pistons for less than $250.

Ebay M62 ($70); I'm going to re-build it and flip the snout so I can drive off the CCW pulley. I just need to elongate 4 holes to make this happen.

Saab intercooler ($50): fits around the radiator.

TurboXS BOV ($30): for when the throttle is closed, compressed air can be vented to the atmosphere. I think the one I have has a 14 lb spring in it, so I need to probably drop that down (6-8 lbs is the goal).

Engine management ($??): Ok, I'm clueless. I think I'll be good with a rising rate fuel pressure regulator and a missing link. Changing to OBD1 and chipped ECU is going to cost way to much. Thoughts?

Tuning: wideband O2 sensor and gauge are considered driver feed-back and don't count in the budget. Other than adjusting the fuel pressure regulator, how else can I tune this?

The car is only used on the track. I set the shift light at 6000 because we run 14.5 hour races. If it idles at all that would be good, but it's no daily driver. This motor has to perform between 3000 and 6000 rpm. We are building a spare motor as well for when we melt a piston during the inevitable lean condition, but that's plan B.

Anyone have experience blowing OBD0 EFI CCW 2.0l motors for cheap?

 

You can tune OBD0 EFI. The options suck but they are there. TurboEdit is free and supports OBD0. And I doubt the rom burner counts in your budget as its not a part of the car, but those are ancient so they should be cheap/free anyways.

 

i was gonna say you might be able to use a fmu from a jrsc! you can find them pretty cheap, and get some bigger injectors maybe some prelude injectors or even rc 310cc injectors would work with the jrsc fmu.

 

Is a FMU the same thing as a rising rate fuel pressure regulator?

I will check out TurboEdit for sure. Anyone have a source for FMU, missing link, or tuners who have burned a ROM in the greater Philadelphia area? Do I need to put a socket on the ECU?

This motor is not VTEC, but from the reading I've done on VTEC B20's it looks like the pulley ratio (crank to nose) is 3:2 for the kind of boost I'm looking for (6 psi). I read that a 6" crank pulley matched with a 4" nose pulley makes 6 psi on a VTEC B20. With an intended redline of 6000, that would make the blower turn at 9000 rpm, which is still close to its peak efficiency. Anyone who's super charged before have any comments on this math? Any corrections for the restrictions due to intercooling? Will intercooling help prevent knock? I don't want to have to run a meth/water system if I can avoid it.

For the blower rebuild; I'm pretty sure this is a gen2 M62, but much of the epoxy has flaked off the rotors. Any tips for cleaning the rotor and case internals? There is a lot of sludge. Would walnut shells and a blast cabinet be too aggressive? Re-epoxy coat, or just polish?

Thanks for the info so far. I'm a total novice at forced induction. If I need to go up an injector size, what year/models should I look for in the junk yard?

 

The fmu is rising rate but instead of 1:1 it's more like 12:1 or 10:1.. they make discs where you can modify the ratio. I would recommend a walbro 255 atleast, hell use a knock off since it's a lemons car

But with turbo edit the fmu is not needed since you'll have a chipped ecu you can tune fuel and ignition without a rising rate regulator.

Dsm 450s (blue tops) will be perfect. Sometimes you can snag a set cheap from a pull-a-part if a turbo dsm just got on the yard as they seem to get picked first. You can get a complete good set off of ebay for 25-100 dollars but again a walbro 255 is needed at the least. Stock pump won't support **** for power

I'm assuming you're going to mount the supercharger where the AC bracket use to be as a lot of D Series guys do, that gives you the most belt wrap and allows very easy plumbing into your front mount intercooler. The bracket can be made out of scrap plate steel or even angle iron... it doesn't have to be fancy it just has to be able to both the damn thing down hold it in place

 

This is great info. Would whatever pump is in the car with the DSM 450s also work? I don't know which will be cheaper. Looks like new a Walbro from Summit is only $90.

I am going to mount the charger nice and high to make room for the outlet manifold and cooler ducting. We burned up our alternator running it at high RPM for so long, so I think I'll switch it to the smaller of the two crank pulleys. I plan on relocating it anyway with a custom bracket. That way I'll have room to build a bracket for the charger. That thing weighs as much as the cylinder head, so I need to support it pretty well.

Thanks again for the ideas. I feel a lot better about engine management now. I'm still looking for a TurboEdit resource, and hopefully I can find an engine dyno in the area.

 

Evans tuning

 

Thanks for the tip. I sent Evan's an email.

 

I talked to Jeff Evans. He can't help with OBD0 tuning and suggested I convert to OBD1. If I use the bypass valve built into the M62 I should be able to omit the BOV and free up $30 in the budget. That leaves me with $130 for engine management ($250 - $70 SC - $50 IC). Socketed P28 and P72 ECUs are all over ebay. Alternatively, I can raid a junk yard for an ECU and socket it myself. If I get the pin-out, I can hard-wire the OBD1 plugs in. Chips are pretty cheap, so I should be able to get a conversion done in budget. Tuning expense does not go against the budget since it isn't technically spent on the car (just moving electrons around a microchip).

So, if I go this route, the plan would be to burn a chip and not run a S300 attached to the ECU. Is this possible? Tuning challenges? Better off with a FMU?

Thanks guys. A build thread will be forthcoming one I've got a final engine management plan.

 

It would still be better off to run a chip. You could tune the car on an ostrich device using like chrome for example. The moates ostrich device allows realtime editing like the s300. Tune the car on the ostrich and once you get the tune all figured out, burn that to a chip and ditch the ostrich. However I'd consult with you turner first and see what they are comfortable with.

 

Im shocked he wont tune OBD0. Is TurboEdit too far out of comfort zone? Ive street tuned a turbo 91 CRX with TurboEdit and the Ostrich way back in the day. All Honda ROMEditors are fundamentally the same at the core. I dont really see a benefit to pay for parts/do work to upgrade to OBD1 just to use the same Ostrich burner but a different ROMEditor. Especially when the budget is critical. I dont get it. Maybe look for different tuner or try tuning it yourself.

An FMU wont give you the control you need. And it does nothing for ignition. Dont waste anymore time considering it.

 

This is cool stuff! Rare to see these kinds of builds like this.

 

Up until around 2001-2002, damn near every street driven Honda with forced induction had either an FMU or used the "S-AFC hack". It was rudimentary, but it got 200+HP out of the motors decently well.

However one you may consider, is to weld a T25 flange (or something similar) to exhaust somewhere and run a turbo. That way you don't have deal alinging brackets. And you get simpler control over the boost level (and better thermal characteristics as well).

Google image wasn't too helpfull showing what the stock manifold looks like. If its cast you will probably be ok putting the turbo where the cat bolted up, but if its tubular you may need to put it further back to keep the heat off the tubes.

Just ideas.

 

I had the safc hack on a turbo gsr back in 02.... Yes it worked, but I'd doubt it would last run for 24 hours on the track....

 

I run Turboedit, the latest version with ECUcontrol and ExtraTables plugins. Tuning is a breeze with datalogging and all the easy to use features.

Ive used it on n/a and boosted non vtec setups, and on 240/450/550/680cc injectors, stock/2.5/3 bar maps sensors and the car always ran perfect. Its effortless to use this program.

Just to throw this in there, for the chips you burn you .bin tune on, use the SST chips, Ive had problems with the AMTEL's in the past.

Xenocron.com sells alot of the needed supplies and good info in the tech section of the site

 

I am definitely going with the supercharger. The stock manifold is a 4:2 casting followed by a 2:1 steel tube. The bolt hole pattern isn't symmetric so flipping it over is out. Besides, who has a supercharged B20A?

I'm not totally convinced that using an FMU is a bad idea. It seems to me (having no experience) that in the worst case it's a waste of fuel. So is all of racing, really.

I would love to learn about tuning with TurboEdit. I'm sure I would be a better/smarter/less useless person if I could figure stuff like this out. The problem I foresee is not having anyone in the area I can go to for help. I can handle any mechanical problem, but when the computer in the car won't talk to the computer used for tuning, I get lost real quick.

I downloaded TurboEdit. I better start reading. Thanks guys.

 

Update:

The head on our current motor was shaved .008". It's NA now and I don't know the actual CR so we are running 89 octane to be safe. For the supercharger build, I am trying to figure out how thick of a head gasket I will need to keep the CR reasonable. I think the supercharger will max out at 12psi and the stock CR is 9:1. I think I'll be alright if I get a HG that is in the neighborhood of the stock thickness + .008".

So, basically I need to know the stock HG thickness. All I have is old chewed up gaskets: anyone know the stock head gasket thickness on a B20A?

Other than that, I am going to tune with TurboEdit so I need to get a eprom emulator, chip burner and socket for my ECU. http://www.xenocron.com/ has links for all this stuff, but if you guys have suggestions before I purchase, I'm all ears.

I got an Innovate WB O2 sensor and gauge.

We have a race next weekend so wish me luck.

 

You dont need a thicker head gasket. It will be fine with the stock head gasket. Its .026" btw.

 

super chargers are good between 10:1 to 11:1 cr
10.5to1 is the sweet spot
they like higer compression unlike a turbo

if you want to work out the CR try this calculator
http://www.csgnetwork.com/compcalc.html

 

I'm assuming you're going to mount it in place of the ac pump once you swap the drive? It's what a lot of d series guys have done and it allows super easy plumbing for a traditional front mount intercooler

Plus you can build an idler pulley and tensioner pulley between the charger and the crank pulley to get maximum belt wrap (if it is mounted high) If you mount it right you can eliminate the dler and just have a tensioner pulley to get good belt wrap (mount the charger lower on the front of the block)