Found a local place that has both a Chassis, and engine dyno.

after talking with the owner for some time, he explained to me the many addvantages of using the engine dyno.

some things he pointed out:

much better load and rpm control
much more precise
much quicker tuning,
costs lest (by a lot, his estimates 4 hour engine dyno tuning is $200, same thing on the chassis is $400)

more power. sounds like the way to go for me...


I am not familiar with tuning, the haltech manual is short to expain engine dyno tuning procedures.


it pretty much says too tune each load bar, while holding an RPM stepping the load up slowly

this makes sense, hold the motor at say, 3000 RPM and go through each load bar and adjust for the desired A/F mix.


so here are my questions:

First of all, how can I get my rotary to mate up to the chassis dyno. THe guy said my bellhousing might work, but a Rotary to Chevy/Ford conversion bellhousing might be needed. Hes has not worked with a rotary before.

when tuning fuel curves
on boost im thinking a flat 12;1 ratio tuned up to 18psi. Should I gradually go into rich or should it be abrupt when the secondarys come online.? I would rather have this be reliable than make the most power.

what should I be running in the vacuum range? 14;1??

how much should I play with the ignition and trailing. What should I look for when tuning?

Im using a hitman map right now. It seams to run great in the vacuum range, although it is guzzling gas when cruizing. Cant boost due to a tuning problem, but I think it is too rich. seams to be a large jump when the secondary come on.


here is my current setup.

Good condition JDM 13bT 1991

SS mani, To4b turbo, 50mm wastegate Volvo Intercooler, and tial 50mm BOV full AN fuel system. 3 in exhaust

Haltech E6k, pre-mixing

 

nobody?

I cant seam to find any threads on optimum A:F at various RPM and load.

 

Maybe no one wants to reveal their "secrets"?


-Ted

 

im not looking to break records here,

just trying to tune for a great running engine that is somewhat reliable.

I plan to tune it up to 18 psi, but I plan to run around 12-14 on the street

this is what im thinking.

closed throttle to near atmosphere: 14:1
getting closer to 13-12:1 as I get closer to atmo,

13-11:1 as boost gets higher and higher.


how should I adjust ignition? I am using a Hitman starter map

 

Sorry, I don't deal with wide-bands so I can't help you out here.
I find them notoriously unreliable.
I use EGT gauges myself.


-Ted

 

he says he has a wideband, but honestly doesnt tune much with it.


he tuned by measuring air and fuel flow and calculating a/f ratio

 

And as far as tuning with a WideBand or the EGT probe, nothing beats tuning with both at the same time, they complement each other and give different read outs/conditions all together.

I always get better results with both of them, if i only tune with one something always gets left out.

 

He must not have access to a chassis dyno that can hold a load. Brian Kennedy was up here at the end of May with his dyno dynamics chassis dyno that can do just that. He would hold the load then adjust the maps on the two cars I saw him tune. First he'd do the low load tuning then gradually work his way up to atmo. After that he'd do full pulls while watching the graphs and making adjustments from there.
I think tuning it on a engine dyno would be a ton of unneeded work. Think of all the stuff you'd have to hook up. You would want to run the same exhaust, fuel pump, air intake, intercooler ect.. I think your problem is you need to find a chassis dyno that can hold a load. Turbo rotaries are a bit different than the carbed V8's he tunes everyday.

 

A chassis dyno might be better for engine tuning, but think of all the time you have to spend making adapters for the bell housing, removing and installed the engine, hooking up the fuel system, removing the haltech/harness from the car. I figure it would cost more by the time you but into it. It would be easiest to find an experienced tuner with a chassis dyno who has worked with the haltech in rotaries. A chassis dyno might be better for engine tuning, but think of all the time you have to spend making adapters for the bell housing, removing and installed the engine, hooking up the fuel system, removing the haltech/harness from the car. I figure it would cost more by the time you but into it. It would be easiest to find an experienced tuner with a chassis dyno who has worked with the haltech in rotaries.

 

well here are my pros and cons of this.

Pros:
He has both a chassis, and engine dyno. He says he gets consistently better tunes and higher HP when using the engine dyno.

Engine dynoing is cheaper by the hour. a 4 hour tuning session is $400, a 4 hour chassis is about $650

As far as removing the engine and ****, I didnt do a great job of Converting the TII tranny to use the FB shifter, and it has problems getting into first. Not to mention it has 160,000 on it, and Im looking for a new one. I will be pulling it out anyways.


as far as the fuel is concerned... My entire fuel system is AN, the pressure regulator is mounted on the engine, and he is equiped for, and experienced tuning Fuel Injection.

and for the electrical and haltech, I am seriously considering rewiring the ENTIRE car with a Painless 12 channel kit over the winter, and starting over with a new UNTERMERIMATED harness. THere are a LOT of unused electrical stuff in the engine bay that I would like to get rid of, but I dont want to **** with the stock harness. Most of the main stuff has already been rewired anyways.

I can use my existing harness to tune on the dyno.

Cons

must bring and hook up the following things.

Turbo manifold, Downpipe, and first muffler.

Oil cooler and lines (not really a big problem, my lines are extra long)

intercooler and pipes.

make the engine fit on the dyno.


he says it takes a evening or so to hook everything up, but I only get charged for time actually tuning.