Is it safe to use a reliaboost with stock chips, or is there an issue with fuel in certain areas of the boost curve?

Thanks
Mike

 

It's ok if you leave at stock boost level.

If you just raise the boost and the car is otherwise stock, then you are asking for trouble.

 

I am not sure about that. The stock boost curve (K26 #6) hits 11 psi at 3500 rpm then is dialed back by the CV to about 7.5 psi at 5800 rpm. If you set the reliaboost to 11 psi and bypass the CV, it should hold 11 psi to high rpm, which will require more fuel than the stock chips are mapped for. If you don't bypass the CV, the results seem to be unpredictable.

I would like to see a AFR trace of a reliaboost with stock chips before I ran it that way.

 

That is why I said otherwise stock, if the CV is deleted then the car is no longer stock.

 

The reason I asked about the Reliaboost was actually because I saw a boost curve map while doing a search. It did just like Waterguy said, held boost till high rpm, and did not drop off at hih rpm like stock. There was a big difference in boost levels in the higher rpm. Thats why I was wndering about the fuel to match this at the high rpm's. So I guess i'll wait till I get chips to get a MBC. Right now all i wanted it for was to get rid of the CV and simplify thngs, as I'm tracking down a vaccuum/boost leak.

Thanks
Mike

 

Here's the post I'm reffering to:


Take a look at this:



Notice that the stock boost-curve is far from flat. It rolls on smoothly, but laggy. Then it drops quite a bit of boost by redline. This is partly due to the intentional programming in the KLR as well as a weak wastegate spring that allows exhaust pressure to push open the valve prematurely, thus dumping boost. As a result, at the high-RPM range, you'll see that there's a humongous 4psi drop in boost. Not coincidentally, the stock wide-open throttle fuel-maps in the chips have a similar curve.



Now, when you add an aftermarket boost-controller, you end up changing the boost-curve (see AccuBoost curve above). At the low-end, the extra flow from boost coming on quicker is not that significant and there's enough excess fuel programmed in to take care of that extra flow (stock chips are too rich in mid-range anyway). However, at the high-end where there's a bigger difference in flow-rates, especially with the fuel-map being dialed back, you'll definitely end up going lean, dangerously lean. The result of using manual controlers with stock or mismatched chips is the typical V-shaped air-fuel curve like this:




There's easily 10-15% more torque and 5-10% more power to be had from this engine if the fuel-curves can be cleaned up to be the opposite. Mid-range torque is best achieved with a slightly leaner mixture, around 13.0:1. This also creates hotter exhaust gases to help spool up the turbo quicker, thus lowering turbo-lag. Then the high-end horsepower is best achieved with a richer mixture, like around 11.5-12.0:1 (depending upon ignition settings).

 

Crap, pics didn't show up.

Here's the thread, look at Danno's post

https://rennlist.com/forums/showthre...aboost+install

 

"Thats why I was wndering about the fuel to match this at the high rpm's. So I guess i'll wait till I get chips to get a MBC."

You could get a chip-kit with MBC all bundled together...

 

I will get the chips , just not yet, wanna keep it relatively stock for now.

Danno, what do you think about adding the Reliaboost on a stock motor?
Thanks

 

Sorry - not trying to hijack the thread here , but Danno do you have a chip/MBC/upgraded wastegate package out? Very interested in one of these.

 

"Danno, what do you think about adding the Reliaboost on a stock motor?"

Yeah, you can use it, but I would set it to no more than 1.5-bar max on the stock gauge. This is to keep the high-RPM boost comparable to stock to prevent getting too lean. You'll end up with stronger low-end, weaker mid-range and same top-end.

Scottz, sent you an email!