View Full Version : Hellacious Spoolup with Piggyback Control

07-10-2003, 11:47 AM
Ladies and Gentlemen,

I found a dirty little secret involving my car and a little thoughtful tuning In the spoolup range (0-10psi). We put a little extra timing in (I'll post my ignition map shortly), and and fattened it up a hair...wow! My car has always had a lean spot at low rpm/high load. Upon adjusting the advance in the ignition table in degrees (0psi)1-2(Boost Threshold)3-2(10psi)-1-0, and putting a little more fuel in down low as well, it was amazing to see the difference in spool. Not to mention the fifty peak lb ft. of torque we found...The car hits so HARD at 3000rpm...It'll boil a little smoke off the tires halfway through an intersection if you hammer the gas at the light.

Something to think about,


07-10-2003, 12:29 PM
Which piggyback control are you using?

07-10-2003, 12:44 PM
I am unfamiliar with a piggyback control. What is it? How does it work? What about this makes it so effective

Magnum TE
07-10-2003, 04:42 PM
we all want one now!

07-10-2003, 04:49 PM
i love the way my B230ET spools. so far no matter what my boost setting i hit full boost by 2200RPM. make's me worried about th econ rods but if it goes it goes.

Hank Scorpio
07-10-2003, 04:57 PM
Sweet Eric, Im going to have to try that on my car when its running. Im going to see how much timing I can get away with and use the BTM to pull it out at a quick enough rate :D


07-10-2003, 07:30 PM
Perfect Power SMT6 (Smart Tuner)

It modifies mass airflow signal, crank trigger signal, and drives additional injectors in my configuration.

I am using a MAP sensor to scale the tuning maps according to boost pressure/RPM as opposed to TPS/RPM (since I have none).

07-12-2003, 09:14 AM
I used a boost retard ignition years ago on my 242T and found that running lots of initial advance helped response considerably. I have one on my 745T now. Low CR turbo cars wake up a little off the line with more advance, but if you don't take out that extra advance later, you will get detonation if you run much more than stock boostIts not as good as a piggyback, because it provides a linear retard and not a fully programmable retard, so you will be leaving power on the table in some throttle positions and boost and rpm ranges.

Interestingly, some of the better aftermarket EMS have an "anti lag" feature that will help spool turbos. I believe it works by dumping fuel and RETARDING timing. I think this anti lag feature is more of a way to handle an oversized turbo than to get the best response from a reasonably sized turbo.

Programmable control is definitely the way to go. This is exactly what Mike Aaro has been advising all along to mostly deaf ears -- programmable control should be at the top of the priority list for a motor that is to be hotrodded, rather than one of the last mods people try. It took me two motors to realize the value of that advice.

I wonder how Eric's piggyback would work with a MS conversion? The AMM could be ditched in favor of a MAP and TPS and Air Temp Sensor, and the OEM rpm limiter would be gone, yet the ignition could still be programmed. Is there an ignition rpm limiter? From reading the Volvo green books, it appears that there could be one, set a bit higher than the fuel rpm limiter. Does anyone have MS up and running yet on a 7/9 series? If so, is there an ignition based rpm limiter?

07-12-2003, 11:27 AM
MS has no control over ignition... YET.

There is a firmware update out that lets you control ignition via the fast idle output... but I haven't tested it yet.

The SMT and the MS would easily be at or more the cost of a good full EMS. I will be running the MS on the stock EZK for a while, and will be switching to a Crane boost-retard capable ignition shortly after. UltraMegaSquirt will be released in the next month or two as well, combining MS and a fully programmable distributor-less ignition.

07-12-2003, 03:13 PM
Ultra MegaSquirt huh? Do you know any more details about it? Is there a waiting list to get on?

I want to be one of the first on this board to try the ultraMS. See how it works for everyone.

07-12-2003, 03:54 PM
I have also wondered about the various rpm limiters on the volvo...

Pennybridge Pioneer
07-12-2003, 11:32 PM
ultra mega squirt makes me drool in my sleep...

07-12-2003, 11:40 PM
thats what i'm :wave: waiting for, hmmm aahhhh ultramegasquirt :lol:. gives me a direct swap over from motronic without having to sort out some out ignition system :x:

07-13-2003, 12:17 AM
omg... thank god we didnt order out megasquirt system yet... this is awesome... i want ! o damn... i just ultrasquirted my self..... :oops:

Pennybridge Pioneer
07-13-2003, 03:39 AM
keekles....ultrasquirted.....but hey, what will be the best inject0rz for ultramegasquirt? ford brown tops? or whatnow?

the poi
07-13-2003, 05:39 AM
keekles....ultrasquirted.....but hey, what will be the best inject0rz for ultramegasquirt? ford brown tops? or whatnow?Depends on what flow you want, you bloated decaying whale carcass.

What will we need to be looking for ignition-wise tho? Aren't coil-on-plugs fairly new and hard to find in a junkyard(read: expensive)?

1989 765Ti dark charcoal metallic
1985 B230FT
Mods: MBC @ 12psi; cold air intake; VDO boost gauge and A/F meter integrated into clock face panel; 16 x 7.5 Voxx MGR 5-spokes; Yokohama YK420's 215-55-16; crazy red/grey two-tone interior
On the WorkBench: strut tower brace
In The Mail: iPd 25/25 anti-sway bars, TME sport springs
oh yes, more to come....

07-13-2003, 01:24 PM
chysler uses em for there 6 cyl cars, so i would venture to guess that they also use them for the neons and such...

07-25-2003, 01:03 PM
What bumpstick you using?

07-25-2003, 01:05 PM