Finally installed my Thrasher chip

[Little6pack]

I finally installed my street thrasher 92 chip Friday.
My fuel upgrades had been made a few weeks back with new walboro pump. I re-checked my fuel pressure at 45lbs as recommended.

I ran the GN for awhile then went for a short ride.
The chip seems to make the engine idle smoother & have better
bottom end response.

Coming out of a side street onto a clear stretch of road I
decide to get on it & see how it does.

WHOA!! BOOST went wild.... right to 20 & the motor popped once real loud.
SCARED the CR_P out of me.. I pulled out of the pedal real fast

This happen to anyone? I never expected 20 lbs? I figured the boost would only be a tad over 15.

 

[Pronto]

I have the cat removed like you and also a Hooker catback system. Before I removed the cat-15lbs, after 17lbs. I would guess that since you have no cat either, you would have gained 1 lb from that. On their site they say the chip will give about 20-21 lbs of boost in first. Bet you need new wires. Mine are on the way.

 

[Snorman]

I went from 18-19psi with an RA93 to 22-23psi with a T-92.
Even with more boost, my car didn't like the T-92. I dialed the boost back to 19-20psi. My KR and O2's were good, but on the next trip to the track, I ran 2/10th's/2mph slower than I had been running with the RA93 at the same boost. I was like..."WTF?". Right in the pits, I put the RA93 back in, set the boost where it had been and the car picked back up to where it was.
I think the issue is the that T-92 took out more timing than the RA did.
S.

 

[blackbuick87]

Thrasher 92's can run 17-18 psi normally.

I guess you dont have a scan tool

If not start reading up on headgasket replacement

 

[Nocooler]

Thashers are known for the way they ramp the boost - and it's not uncommon for boost to raise/lower with chip changes.

Turn down the boost - grab the scan tool - and have fun.

 

[Little6pack]

I have the Scan master & looks like I will be installing an adjustible waste gate.

So if I understand this correctly. the THRASHER turns on the BOOST sooner which is a good thing. But because of no CAT & the chips ability to go higher. I need to adjust the wastegate or keep my foot off the tall pedal.

 

[blackbuick87]

The Thrasher works on the concept of less timing and more boost. You should be able to run about 16-17psi on that chip without any knock.

For a near stock car I recommend the T-100 for when you mix in some race gas or alky. My car LOVED that chip on stock injectors

 

[Scott231]

Sorry but have to disagree with some of the above coments.

Thrashers are engineered to go as fast as possible with the octane minimum posted on the chip. Note that there are only 3 things you can do to change the engine's performance when the engine volume is constant (and for the Thrasher this means stock heads, cam, intercooler, turbo; and free-flowing exhaust and air inlet). The three things are change timing, boost or fuel, and only one of those is easily adjustable by the driver - boost. As such, the timing and fuel are set to attain a good burn of the air:fuel mixture at X amount of boost, where X = the highest amount of boost Tom could run with his test car. You wanna change octane, change the chip with more timing.

Another note of importance - all stock fuel injector chips run the injectors static at WOT (unless the original hacker foecked up the chip). This includes Thrashers, RA, etc., etc.

Here is a clever little trick that Tom incorporated into the chip. Remeber, ALL chips cannot control boost levels based on a boost level input...there is none on the stock ECM. Tom set his boost ramp so that a stock length rod would allow 20-21 psi in first gear, but the boost is scaled down in each succesive gear. A properly tuned TR can easily run this much boost in first because there is minimal load on the engine. As the load increases, the boost is scaled back. Now the neat thing. If your engine can't handle the boost load, you can lengthen the actuator arm instead of shortening it...by re-shortening every so often, you are ruining the spring in the actuator. Something that will not happen with a Thrasher.

Of course what a lot of people do not understand is that cutting edge chip technology from 1993 applied to a car that is now 10 years older doesn't always work the best as that 17 year old just isn't in as good of a state of tune as you'd like to think.

Why somebody would bother racing their car with only 93 octane fuel is beyond me...but my "must-go-faster" bug is getting the better of me, so I'll shut up now...

 

[Little6pack]

Scott,
No racing here. I was just going to test pilot it out & back off.
I did have 94 octane in at the time.

The instructions I got never really mentioned a waste-gate that was adjustable. OR The ignition components being sub par may play into equation.
Had I known all this prior I would have replaced them.

Seems the TR's are not as easy as I was let to think..
I kept reading chip, air cleaner, test pipe, fuel pump & regulator & walla Instant magic..

However since this happened to me I will keep trying to drive with the THRASHER & remember not to get on it in 1st gear so quick. Until I can install a WG & Ignition stuff.

Anybody know what I will need? Wires, coil packs, etc

 

[tjthorson]

I know that pop. Its scary.

Time for valve springs...

 

[blackbuick87]

You dont need an adj wastegate to run a Thrasher. Sounds like your puck may be sticking.

Lots of things can cause popping
Bad MAF
Bad coilpack
Bad module
Bad wires
Bad plugs
Bad O2
Bad valvesprings
Bad fuel pump
Bad injectors
etc

Good luck
My pop turned out to be a bad module but yours may be different.

Good luck

 

[Little6pack]

eee Gawd! ONLY 20k on my engine & you guys are telling me valve springs.

I can see maybe stuff like plugs & wires & injector leaking due to age. I have new walboro fuel pump in there.

Think I am gonna just give up on TR's.
I should have left it alone.
Well I can always put it back to stock.

It is like a runaway snowball.
Make 1 mod, then it affects something else.
Make another mod & it affects something else.
Hey I am repeating myself. Oh well you get the idea..

Maybe I should just throw the stock chip back in
& just enjoy it AS IS..

Being a DAD I don't street race all out. Maybe some 200 yard type red light action then back off.

I may do 1/4 drags 1 time a year anyway.

Who knows maybe I can break 14 with just the walboro, test pipe, air cleaner, 100 oct & a nice cool night in a couple of weeks.

 

[blackbuick87]

Originally posted by littlesixsteve
eee Gawd! ONLY 20k on my engine & you guys are telling me valve springs.

Think I am gonna just give up on TR's.
I should have left it alone.
Well I can always put it back to stock.

Holy crap, one little pop and sell the whole thing? What do you expect on a 17 year old car?
If that is enough to make you quit you probably should sell the GN to someone with more fortitude and buy yourself a Rustang

Oh, BTW,
if the problem is one of the things I listed above then it will only get worse with time, and "putting it back to stock" will do nothing

And valvesprings that have been under compression for 17 years can fail or get weak, the mileage is meaningless

 

[Little6pack]

Actually I never said sell

Just not do anymore to the car

Please not a ford!

 

[scottyb]

Mine popped the first time I went WOT after these 2 changes:

1. Unplugged the WG solenoid vent (to get 15lbs instead of 11 when I bought it)

2. Ran a non-stock chip (RA93), 17lbs.

It has not done it since, except for bad coil pack. What I am trying to say is just get a grip on the excessive boost, but don't immediately write things off because it popped once. My coil pack failed more than a year after those initial pops, and it ran flawlessly during that time.

 

[Scott231]

Originally posted by littlesixsteve
eee Gawd! ONLY 20k on my engine & you guys are telling me valve springs.
<snip>
Who knows maybe I can break 14 with just the walboro, test pipe, air cleaner, 100 oct & a nice cool night in a couple of weeks.

Steve, instead of looking into buying 20 new parts to remedy a symptom - first do some testing to fing the problem.

It could be detonation related - Put some 100 or better octane in there and see if the problem goes away.
It could be ignition related - test the coil pack and/or borrow some known-good parts.
It could be fuel related - tape a fuel pressure gauge to the windshield and monitor the reail pressure rise with boost. Have the injectors been cleaned recently?
Maybe the motor is a little dirty inside - try a can of GM Top Engine Cleaner to remove some carbon and crap that has accumulated in the last 17 years.

All of the above are discussed onthe gnttype.org website.

Oh! and if you think wires, plugs and O2 sensor are excessive items to have to replace...have you changed your oil?

 

[Little6pack]

Scott: It could be detonation related - Put some 100 or better octane in there and see if the problem goes away.

LSteve: I can try this. I do have a sunoco that has 100 unleaded
But I have fresh 94 in there. When I bought the street
chip it said 92?

Scott: It could be ignition related - test the coil pack and/or borrow some known-good parts

Lsteve: I can borrow my friends not sure if his is any better

Scott: It could be fuel related - tape a fuel pressure gauge to the windshield and monitor the reail pressure rise with boost. Have the injectors been cleaned recently?

Lsteve: Dam I bought the rail butt end style gauge.

Scott: have you changed your oil?

Lsteve: Brand spanking new SYN oil

Scott: if you think wires, plugs and O2 sensor are excessive items to have to replace.

Lsteve: I did not say EXCESSIVE to these items But I did say it about valve springs.

What kills me is I hear guys with TR's running around with original engines with over 100k & pulling some good 1/4 times.
My motor has only 20k & springs already?

Like I said I followed thrashers instruction but now it is encompassing more than I wanted. Hey it is not only me with POPPING when using a thrasher.. A few other souls have the problem too but are afraid to air an opinion as to not make waves.
That is what this board is about.. Now that I am getting some answers as to what to check I am on it.

 

[ross87t]

My Thrasher always caused a boost spike. About 3psi higher than I had the boost set to. Spool was good, but if I wanted to run 18psi, I'd have to live with the 21psi spike.
I didn't care for that.

Ross

 

[tjthorson]

The mileage is not the issue, its the age of the springs.

Those guys with 100K on their motors unopened that push the boost up ALL have to do the springs.

Its not a major job - just maintenance.

Anyone that has 100K on the stock springs and timing chain is just asking for trouble. Its like saying - its been 10,000 miles since I changed my oil and the car still runs!

Yeah - but not for long.

 

[Nocooler]

Ross - Read Scott's first post. It will spike high in low and 2nd due to less load....and then settle in 3rd as load increases.