How many of you use LBE or similar for a boost controler?
09-09-2002, 11:37 AM
#16
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Thanks for your remarks. I asked this question because likely for Xmas, I will be getting a chip, boost guage, and maybe a A/F meter. I wanted to know if it would be safe to crank up the boost with the LBE that I already have or if I need a MBC.
Any comments?
Any comments?
09-09-2002, 04:49 PM
#17
Race Director
"The only problem with increasing the boost to 16psi is that 16psi is a spike.. I'd rather add a few psi over the entire RPM range than just as a spike in the beginning."
The spike is caused by the trailing off of boost afterwards. If it can hold the preset 16psi for longer, that would be more desireable. The trailing off after the initial boost build-up is caused by trapped pressure between the LBE and wastgate. This keeps the wastegate open too long after boost has been cut to preset levels. That's why the better electronic boost-solenoids have three ports, with an additional drain to bleed off the pressure and allow the wastegate to close quickly. Running the LBE in series with the stock CV will allow for this quicker and more precise control since wastegate won't be held open longer than necessary.
"Someone please correct me if I'm wrong but wouldn't using an LBE alone to increase boost be very dangerous because you don't have recalibrated chips and/or an adjustable FPR to prevent detonation? Aren't the stock chips only good for 14psi?"
Yes, very, very dangerous because the stock chips won't meter fuel to match the increased flow above stock 11.5psi levels. Then overboost-protection activates at around 13psi and cuts fuel completely when you're under full-throttle. Make sure you're wearing our seatbelts or else you'll go through the windshield.
"So if the LBE needs a 5 psi "cushion" then the LBE should be set to open at 7 psi. There was a recent thread where a guy stated he contacted Lindsey and they stated just that."
Yup, there's a difference between intake-manifold pressure (boost) and the actual pressure that opens the wastegate. It's the boost-controller's job (MBC, LBE, electronic), to manage this differential to mantain a constant intake-manifold pressure. See this thread: <a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=15&t=010253" target="_blank">Topic: LBE intalled, getting weird readings </a>
"Where is this Fuel Quality Switch?"
It's under the DME, see here on how to adjust it: <a href="http://members.rennlist.com/951_racerx/FQS-adjust.html" target="_blank">951 RacerX FQS-adjustment procedure</a>.
" Is this the switch we who have Guru Racing chips set to determine what maps to run when we change injectors, etc? "
Yup, that's how we adjust the injector pulse-width to compensate for larger injectors. Here's how the FQS switch works for our chips:
0-stock = 34.5lb stock injectors
1 = 55-lb/hr injectors
2 = 65-lb/hr injectors
3 = 75-lb/hr injectors
Then positions #4-7 are the same with a manual 5-degree ignition retard for 18-20+psi of boost.
We also use the regional-coding plug to allow you to select alternate ignition maps as well. The Australian MAP#3 has even more agressive ignition timing for those using 100+ octane race gas.
The spike is caused by the trailing off of boost afterwards. If it can hold the preset 16psi for longer, that would be more desireable. The trailing off after the initial boost build-up is caused by trapped pressure between the LBE and wastgate. This keeps the wastegate open too long after boost has been cut to preset levels. That's why the better electronic boost-solenoids have three ports, with an additional drain to bleed off the pressure and allow the wastegate to close quickly. Running the LBE in series with the stock CV will allow for this quicker and more precise control since wastegate won't be held open longer than necessary.
"Someone please correct me if I'm wrong but wouldn't using an LBE alone to increase boost be very dangerous because you don't have recalibrated chips and/or an adjustable FPR to prevent detonation? Aren't the stock chips only good for 14psi?"
Yes, very, very dangerous because the stock chips won't meter fuel to match the increased flow above stock 11.5psi levels. Then overboost-protection activates at around 13psi and cuts fuel completely when you're under full-throttle. Make sure you're wearing our seatbelts or else you'll go through the windshield.
"So if the LBE needs a 5 psi "cushion" then the LBE should be set to open at 7 psi. There was a recent thread where a guy stated he contacted Lindsey and they stated just that."
Yup, there's a difference between intake-manifold pressure (boost) and the actual pressure that opens the wastegate. It's the boost-controller's job (MBC, LBE, electronic), to manage this differential to mantain a constant intake-manifold pressure. See this thread: <a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=15&t=010253" target="_blank">Topic: LBE intalled, getting weird readings </a>
"Where is this Fuel Quality Switch?"
It's under the DME, see here on how to adjust it: <a href="http://members.rennlist.com/951_racerx/FQS-adjust.html" target="_blank">951 RacerX FQS-adjustment procedure</a>.
" Is this the switch we who have Guru Racing chips set to determine what maps to run when we change injectors, etc? "
Yup, that's how we adjust the injector pulse-width to compensate for larger injectors. Here's how the FQS switch works for our chips:
0-stock = 34.5lb stock injectors
1 = 55-lb/hr injectors
2 = 65-lb/hr injectors
3 = 75-lb/hr injectors
Then positions #4-7 are the same with a manual 5-degree ignition retard for 18-20+psi of boost.
We also use the regional-coding plug to allow you to select alternate ignition maps as well. The Australian MAP#3 has even more agressive ignition timing for those using 100+ octane race gas.
09-09-2002, 06:09 PM
#18
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Join Date: May 2001
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I had the Enhancer for a short while. I was running both a manual boost controller and the LBE at the same time (I didn't know any better at the time). I was testing on a county road near my home, turning up the boost gradually, then my car took off like a shot dawg and boom! white smoke pouring out the tailpipe. Took me a couple of weeks evenings only to do all the work to replace the head gasket and a few other things while it was apart. I enjoyed the experience. Sold the LBE, haven't looked back.
Pat Kennedy
88 Turbo S SilverRose metallic; 2.8L, Stage 4 MAF, adj. FPR, SFR hard pipes, 18" Technology hollow spoke wheels.
Pat Kennedy
88 Turbo S SilverRose metallic; 2.8L, Stage 4 MAF, adj. FPR, SFR hard pipes, 18" Technology hollow spoke wheels.
09-09-2002, 06:46 PM
#19
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Ok, so it appears that LBE would not be good to use to increase boost due to inconsistency in holding boost...Is that correct?
I have NOT increased boost...see above, I am making my Xmas list to give to my wife but cost must be contained....
But isn't GURU Racing's chip kit increase boost using a substantially similar device?? Danno, with his infinite wisdom and knowledge regarding turbocharging appears to use such a device...so it must be OK??
Danno, care to comment?
I have NOT increased boost...see above, I am making my Xmas list to give to my wife but cost must be contained....
But isn't GURU Racing's chip kit increase boost using a substantially similar device?? Danno, with his infinite wisdom and knowledge regarding turbocharging appears to use such a device...so it must be OK??
Danno, care to comment?