Rkreigh

Hi folks,

I spoke to a VA tuner about the possibility of tuning the LSV (390, Stg 3 cams) to run on alchy to pass the tough VA emissions

the theory is that methonol will burn much cleaner and I only need enough pump/injector flow to run the car at 15/25 & idle

on my car I have the secondaries removed which doesn't help emissions either

I have to hit 48 HC at 15 and I believe 53 at 25 mph on the dyno

also thinking of installing some fresh bullet cats at the same time so that the "tune plus fresh cats" will equal enough $$$ to grant an exemption in case all of this fails

the tuner has a gas analyzer and can tune on the dyno to "simulate" the emissions test and get the car to run on alchy

once I get through, I'll drain it out and swap back to the good ol haibeck chip

right now the car will only go as clean as about 135 HC and with the big cams it runs pretty rich at idle even though it shows stoich on the "narrow band"

folks have given me quite a few tips on how the big cams and low vac signal "trick" the factory computer into dumping more fuel.

sooooo.......... after all this, do you think with fresh cats and an "open loop" chip the emissions can be cleaned up on a pump gas tune???

has anyone gotten a stroker LT5 through emissions?

let me know if other folks are interested in this. the 25 year exemtion for the 95 ZR-1 is a LONG time off and I drive this thing regularly.

any tips, advice? thanks.

mike100

off the top of my head- smaller injector size and hotter catalysts. if your area tests for NOx, you are probably ok if your cam overlap keeps combustion temps low.

JackDidley

Go E85 or E98. The methanol is bad for the fuel system. Ethanol, not so much.

DDSLT5

Hey Ron - ever consider installing stock cams with an appropriate tune? It is a lot of work, but guaranteed to work. Just a thought.

Rkreigh

don't want to spend the dough to "detune" the engine

I can get an emissions exemption for about 700 provided I get the right sign offs

trying to spend about the same for a more lasting solution that I can switch chips ever 2 years, pass then change back.

e85 or e98 will hopefully allow me to do that.

I can even start the car, warm it up really good, drain the gas and switch chips so cold start won't be much of a problem.

hoping this will work. the tuner has an exhaust gas analyzer, and a dyno so they can perform the same emissions test that VA does

have to pass on both HC and NOX, dillution at 15, 25

with the cams I have they have quite a bit of overlap which is good for top end power but not so great for emissions

I am installing a carbon fiber drive shaft so I'll put some fresh cats on at the same time to help.

I used to spike the gas with "lamp fuel" alchy and get it down to around 96, but then VA cut the emissions standard in half to 48 and that was before I pulled the secondaries

I can as a fall back register the car in GA, but that has it's set of hassles too.

thanks for the feeback, been talking to Corey Henderson about this but he doesn't yet have an exh gas analyzer and TX is pretty far to roll

thanks!

JackDidley

It would not be hard to do E85 just for the test. Could probably just tweak the injector constant to do that. Wouldnt want to beat on it though. Takes a bit more tuning for that.

Graham Behan

Ron,
How the hell are you??? When the "Tune" was done for the secondary delete, was this done with a low TPS switch point for the primary/secondary switch? If so, believe it or not, your HC problem could be the result of a lean misfire, call me if you want to discuss this.

All the best
Graham.

Rkreigh

I will be in touch Graham. I believe the car cuts out the secondary injector at anything less than 1% TPS (idle only).

Mr Haibeck did the tune. car definetely runs rich. I also remember that the original LPE tune was "open loop" and wondered about trying to run an E85 "blend" (maybe more like E35 or so) to clean up the HC

thanks very much for the response. I will touch base

by the way, enjoying the LSV very much sir! some of your best workin IMHO. I have 77k and the car still distorts my face at WOT with both a huge grin and ripples in the cheeks from the Gs.

doing quite a bit with the Twin Turbo Z06 as well and while that car is quite a bit more stout (800 rwhp) it lacks the pinach of the LSV.

finally got the old Turbo Buick T back on the road as well and will soon be baking some drag radials with the "herd" as the racing season is here.

last on my "2 do list" is getting the 80 BB Chevy Drag vette operational, it's a 9.20 full boogie drag car which has far too much dust on it.

good to hear from you. and thanks very much in advance for the advice!

DDSLT5

Interesting. Kinda glad I left my secondaries intact.

Dominic Sorresso

Ron,

I'd be interested in Graham's take on this and the remedy.

Rkreigh

I'll post up the suggestions. I might try the fresh cats and pass on gas spiked with alchy with the open loop chip too.

but I really need to see what works on the exh gas analyzer so I can make sure I pass!!

those big cams with all the overlap are great for power but definetly make emissions a challenge!

locobob

Lean condition on tip-in?

locobob

I still think you ought to make-up an emissions only exhaust center section using some big factory type cats. The bullets flow well but are kind of marginal for cleaning up emissions. Just flange everything for an easy swap in and out.

DRM500RUBYZR-1

Ron,
Much,Much simpler solution.
Kept thinking the exact same thing, and easy to re-use every two years for re-inspection.
Could probably lend / rent it out to others with the same header setup.
Why screw around with the perfectly fine tune and performance.
Big *** cats should be sufficient to clean it up easily.

Marty
1FUNZR1

LT5 Doc

Ron, when Marc built my 415 for me with the Stage III cams, I had him burn a special e-test tune for me. I have removable cats as well. When I e-test, I install the random-tech cats and use the e-test tune. The e-test tune really retards the timing and it always makes the fellows doing the e-test think the car needs a "tune-up." With this tune and hot cats I have passed the e-test. pm me for more information if you want.

Rkreigh

thanks I was definitely thinking about putting some big factory cats on it as my random cats are a few year old and probably not working all that well. like to hear more about the etune.

I'll talk to marc too as a variation of this tune might do the trick

getting down to 48 hc should be doable I hope one way or another!

just trying to do it without breaking the bank

I'm a really cheap guy when it comes to something that doesn't make the car perform better