Another Thrasher Chip Question

S

Six Banger

Destination Detonation
Joined
May 25, 2001
I need one for stock injectors. I am pretty sure that the chip number is 92-28-K2.0. It says next to this number that it is "For stock fuel pressure regulators". Does anybody know if it is in fact dialed in for the Bosch "233" or do I need to have an adjustable one that will allow me to adjust to 45psi static?
 
No, I just wasnt sure that my stock fuel pressure regulator was OK for that particular chip. I just assumed that all Thrasher chips needed and adjustable regulator and 45psi to operate properly. So, if I dont need to buy an adjustable one, that is good for me since money is tight for me right now. I do need a chip though because I am pretty sure that the timing on my stock chip is what is giving me some KR under heavy acceleration on pump 93. Scott, I guess then it is safe to say that the ONLY 28# chip that you offer is for stock "233" regulators? Thanks for the help with this and sorry I am slow to grasp.
 
By design. the Thrasher has an open loop idle that will not learn from the O2 sensor. Therefore fuel pressure is what determines the idle mixture. Use your stock fixed regulator with a Thrasher and it would be about 15-20% too lean. At idle it would stumble and die possibly. In the middle all the cells would be fine. At the top end the Thrasher locks the BLM at 128 which means the fuel pressure is critical. At high boost you could have possibly worse knock than with a stock chip since the chip is designed not to learn for high throttle settings. It works well when you can tweak the fuel pressure to tune it. It sucks otherwise. Also the Thrasher will overshoot the boost set point and drop back down again, partly due to its fast boost programming, you don't want to be lean during that short transition.
 
Maybe, I should just wait until I can do all the proper fuel mods. I have completed all the "spring cleaning" procedures and was hoping that I could do something "easy" to keep the knock down for now. I am not racing the car, but every once in a while I feel compelled to step on it. Besides Xylene and turning down the boost, are there any other ways to remedy knock in an all stock car?
 
I just ordered the same chip myself. I plan on using my "237" regulator in conjunction with my Walbro 340 fuel pump and Hotwire kit. From what I understand, things should be fine with this setup since Thrashers are programmed to work best with 45psi. The 237 should give approximately 45psi. The stock 233's give a couple of pounds less. You should be able find a Bosch 237 off a junkyard car very easily. I got one at a junkyard for about $9. Other's please chime in if I have this incorrect.
 
86T, If you think about it, what are the chances that the "237" regulator will be exactly 45psi? It could be more or less, probably more if you have an upgraded fuel pump that is hotwired. Then you are stuck. I would just splurge for the adjustable one. I have had a Trasher in the past for 92 octane/stock injectors with an adjustable regulator set at 45psi and it worked great, but this has been 3 years and another GN ago. That is why it is foreign to me to see one advertised for stock fuel pressure regulators. I was just trying to get some clarification from Scott. Maybe for some reason I am not getting all my E-mails.
 
Six Banger,

Since I already have the 237 regulator on the car I'll probably just try it out and see how the car runs. I'll probably get an adjustable if necessary if the higher voltage from the more efficent pump and hotwire causes the pressure to "bleed" up like you said. There was a post on the forums somewhere that said when 237's were tested , all of them came to only within 1/2 to 1 psi difference at the most from 45 psi.
 
The 92-28-k2 chip is stock fuel injectors and STOCK FUEL PRESSURE regulators.

The 92-30-k2 chips is also for stock fuel injectors and 43.5psi fuel pressure that can be obtained with either a -237 regulator and an adjustable model.
 
Someone did a test ( I can't remember who right off hand) and all bosch regulators were within 1%-2% of what they were supposed to be, so I'd say a 237 would be pretty much right with what you are looking for.
 
Hell, what do I know? :) .... I just did a search and found that some people who did the Walbro 340 and hotwire mod saw an increase in base fuel pressure and some did not. I guess it does vary from car to car.
 
Originally posted by Six Banger
I guess it does vary from car to car.
Click to expand...

that is true, but if the pressure went up I would say it is because the factory pump wasn't cutting the mustard and the 340 brought it up to stock again. (I only guessing, but it makes sense in my head)
 
Well, not to beat a dead horse, but people were writing that they had for instance, 45psi with the 237 regulator, then after the 340/hotwire mod the pressure went to 48psi. Some say that it was 45psi (237reg.) before and after the mod.
 
I'm only posting what I have heard, I've never done any testing myself...I just bought a used Adj. one here for fairly cheap...if it's in your budget I know where to get a billet top for $50 bucks...From me!!
 
FYI - Buick did a "sneaky thing" in my opinion. The injectors in a turbo Regal tend to flow 28.2 pph with the stock regulator. Therefore, everyone refers to them as 28pph injectors. Fast forward two years and the LC2 motor shows up in a TTA...and the chip shows 30.x pph. As such, lots of people believe the TTA injectors are different...they aren't.

The TTAs recieved a fuel pressure regulator that runs at the "industry standard" of 3BAR (43.5psi). Note that whenever you look into buying fuel injectors, the pph rating they have is when they see 43.5 psi pressure. The turbo Regals only ran something like 38psi. So the 30 pph injectors were rated as 28pph on the Regals and 30pph on the TTAs.

Originally, all Thrashers were simply made for the "industry standard" 43.5psi of fuel pressure. Enough requests came in for a chip that gives the Thrasher features to someone with the stock fuel pressure regulator, thus, the 92-28.

Perfectly clear now?
 
Scott,

That DOES clear alot of things up.
Are all other calibrations the same as the 3 Bar Thrasher chip? Would there be a big performance difference using the 28pph chip against the 30pph chip with the appropriate FPR's?:)
 
Originally posted by '86T
Are all other calibrations the same as the 3 Bar Thrasher chip?
Click to expand...
All Thrashers (except the 92-28-k2) are designed to be used with 3BAR of fuel pressure.
Would there be a big performance difference using the 28pph chip against the 30pph chip with the appropriate FPR's? :) (emphasis added by Scott231)
Click to expand...
No.
 
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