All things being equal you will always make more power with direct port injection on the fuel. The simple answer is a leaner mixture = more power but with a wet manifold the A/F mixture must be way richer to compensate. Not to say you cannot do - I did so for years with my SuperFueler but if you called me today I'd try to talk you out of !!!!!

greg

 

I guess I was hoping for a simple "turn the wastegate screw to increase boost by x psi"
Took a look at Callaway website and looks like they sell a spring to increase boost pressure...
But, you'd need to increase fueling, I imagine.

Looks like the best way to go is to ditch the std ECM and microfueler, and replace it with an aftermarket Engine management system. (Here in Australia, the best is Motec)
Increase the size of the 8 injectors, blank off the ancillary ones, then see how you go..

After that, you'd look at exhaust improvements, then turbo replacements...

 

Just My Opinion - but you'd be crazy to replace the stock ECM. Many of the tuning variables are not available in after market ECM. Besides - again just me - but I much prefer MAF tunes to S/D. I can promise you a new tune with a new MAF and 63 pound matched injectors will astound you !
greg

 

Thanks for the reply, can you please explain what "but I much prefer MAF tunes to S/D" means?
Are you suggesting a "piggy back" ECM?

 

Hi Guys ! All the aftermarket ECM's that I am familiar with are S/D or speed density where a set of VE tables are used to proportion fuel. Your car is of the MAF or Mass Air Flow style where an air sensor measures gms/sec and adds fuel accordingly.

Most modern cars, including the Vettes are of the MAF style.

Your GM 1986 thru 1989 ECM is quite powerful and flexible. Main limitation is the MAF sensor which is good up thru maybe 254 gms/sec which is why the Micro Fueler was added as a stand alone supplemental injector controller.

Your ECM with a modern MAF sensor can easily handle 600 HP: just add the correct injectors and a new tune and plenty of fuel pump !!!!!! LOL

No piggyback computers for me when the on-board GM ECM can sport real time tuning with either TunerPro or TunerCat.

Why rip up a perfectly good and powerful ECM that can sport real time tuning ???

Just my humble opinion.
greg

 

Greg,

I have experience with aftermarket ECM's in a racing capacity and some of them are pretty good - but the factory one does a lot more "nice" things...

Are you saying you can alter the injection timing based on rpm, throttle position, MAF inputs etc within the factory ECM?

If so, surely is a simple as changing to larger injectors, then retune?
Why didn't Callaway do that from the "get-go"?

 

YUP ! And a lot more !!!!!!!
OMG if I had the software (TunerCat & TunerPro) we have now back then I'd be soooo rich !

You cannot imagine how we all struggled ! I wrote the Vette engineers about 2 thousand times and ALMOST but never did get the code. I even had my EE engineer build a simulator so I could try and reverse engineer the chip !!!!!!!!

You just have NO idea how far our aftermarket shops (Moates, TC & TP, etc., etc.) have progressed. In 1987 real time tuning was a dream you had at night !

The 'get-go' was strap-ons (oh I meant AIC's) !!!!!!!!!!!!

You all have no idea how good you got it ! My god a WB was a $2500 wet dream !!!!!!!!!!

I could go ON & ON but enough said !!!!!!!

greg

 

Run an EBL and be done with it, stock harness plugs right it in, just a few repins needed and you will have flash tuning, no more proms, and no more tuning the LV8. I am running an EBL-P4 tuned through TunerPro on my '90 GTA single turbo w/TPI, works flawlessly...

 

Many, Many Ways !

You as the owner of the original Callaway vehicle must make some decisions with regard how to solve a problem or make an update, or change the intention of the original designer !!!

One - if you are handy and an engineer of any sort you'll figure this out for yourself - period.

However if you are a collector and want to maintain the integrity of the original then think about using the stock ECM as intended with the huge advantage of having software to tune it, i.e larger injectors ?

greg

 

PS: flash tuning is cool but not same as RealTime Tuning which your stock ECM with a Moates Ostrich emulator provides !!!

For instance - on the C5 you must make some hardware/chip changes to enable real time tuning. Not so on the C4 ECM. Just plug in the Ostrich and off you go !!! Look - again many ways to go but the Ostrich and some software is SO simple !!!!!!!!!! greg

 

Just took a look at the Ostrich 2.0

It looks ridiculously simple....
Can you really just plug it into your C4 and start making changes live and not have to "reflash" the PROM?

do you need to open the original ECM or can it connect whilst the engine is running?

It's a little unclear if this connects to the ECM?

 

It is that simple ! Send me an e-mail (greg@blowerworks.net) and I'll send you some pics. greg

 

Just throwing that out as another option for you. Ostrich works, but it's old school. EBL has wastegate control, and has calibrated BST tables up to 30-psi to help get you started. My turbo TPI was up and running in literally five minutes from scratch, then dialed in about ten minutes later. Also has VE Learning capability, and is tuned using Tuner Pro V5...

 

tell me more about EBL??? not familiar with this setup. sounds really good

the callaway is a great car to mod IMHO and the sky is the limit with some infusion of modern tech

here is my "transmagorafication" to the callawy if you would like to go to something new

the l98 had some fairly restrictive runners and is "all done" at around 4800 on the hp curve stock turbos help this but these engines are torq monsters and "peak early"

I'd put a modern tunnel ram style intake, and use a megasquirt to control and additional 8 set of injectors running pure meth or e85 with a separate fuel system

that way, you preserve the stock tune, and can take advantage of the cooling of the fuel to run higher boost

the megasquirt can be your boost controller and adds many "fail safes" to keep you out of trouble

another good piece of news is that the megasquirt is very affordable and you can run some nice sized injectors on the *additional 8" without all the tuning and idle hassles

this however is a pretty radical mod be prepared to go all in and save all the stock stuff as it's very valuable!

the texan crowd did quite a few big power callaway builds over 700 which were very impressive

as was chris c.'s personal "beast" with an accel DFI

with the modern tuning tech, the real question is "how fast do you want to go?"

I found out with my TT Z06 that 800 at the tires is about as fast as I can handle.

 

I see Callaway offer a stiffer spring for the blowoff valve.
Anyone had experience with these?
Seems like it might be a simple upgrade for a few extra ponies?

 

The wastegate spring you are referring to is for the 88 and up cars and won't work for the 87 with IHI turbos.