Boost levels on the FF275 Elise...

[madberries]

Hey, I was doing some research and noticed Stephen's old boost dyno here...

http://www.elisetalk.com/forums/show...forcedfed+dyno

My boost gauge reads similar, however instead of leveling off at 7psi it keeps going up till i hit redline which at that point is a little over 10 psi (every time). Is the internal waste gate not opening? Although my car hasn't been tuned yet, I dont see how that could have any effect. Is this normal? Thanks.

[MikeW]

Whether it's normal or not, I don't know. I've seen that myself and wondered. I'd say a call to Forcedfed will tell you what it's supposed to be and if they consider it acceptable or not. Personally, I'd prefer to know if the A/F ratio is within acceptable range at that level of boost.

[gkeller]

The behavior you are seeing is similar to mine. By the way, I found a Unichip tuner in Phoenix. The car goes in tomorrow for tuning.
In higher gears, with a slower build up of RPM, my boost gauge shows a max of 7-8psi. During a standing start, the boost max is around 11psi. My understanding is that the build up of RPM/turbo speed is so rapid, in comparison, that the wastegate is overwhelmed. (boost creep) My understanding is that most dynos are done in 4th gear. I think this would be why the dyno generated documents show 7-8 psi max.

[DPM]

I talked to Casey last Friday regarding boost with the 275 kit and he said it should be about 7 up to 8, no higher.Where did you tap into the vacuum lines for the gauge input? That can make a difference in the readings.

[Casey]

Originally Posted by gkeller

The behavior you are seeing is similar to mine. By the way, I found a Unichip tuner in Phoenix. The car goes in tomorrow for tuning.
In higher gears, with a slower build up of RPM, my boost gauge shows a max of 7-8psi. During a standing start, the boost max is around 11psi. My understanding is that the build up of RPM/turbo speed is so rapid, in comparison, that the wastegate is overwhelmed. (boost creep) My understanding is that most dynos are done in 4th gear. I think this would be why the dyno generated documents show 7-8 psi max.

You are very correct....This is partly due to the fact thar we designed an exhaust manifold that is almost too efficient. On another note....don't always trust an Autometer guage....They make a good product, but sometimes their QC is a little off. With that being said, I always check it against another gauge if I think there might be a problem.

[carlover]

Originally Posted by madberries

Hey, I was doing some research and noticed Stephen's old boost dyno here...

http://www.elisetalk.com/forums/show...forcedfed+dyno

My boost gauge reads similar, however instead of leveling off at 7psi it keeps going up till i hit redline which at that point is a little over 10 psi (every time). Is the internal waste gate not opening? Although my car hasn't been tuned yet, I dont see how that could have any effect. Is this normal? Thanks.

I know this is a little off topic, but how do you like the kit is it the $11k stage 3? Does the turbo kick in smoothly or is it like driving a stock elise that suddenly gets poked with a branding iron at 6k rpm? Do you know of amy problems with turbo heat or anything like that with tracking the car with this set up? How about high speed on the highway. Sorry for so many questions I've been dying to talk to someone who has one.

Thanks, Joe

[madberries]

Originally Posted by gkeller

The behavior you are seeing is similar to mine. By the way, I found a Unichip tuner in Phoenix. The car goes in tomorrow for tuning.
In higher gears, with a slower build up of RPM, my boost gauge shows a max of 7-8psi. During a standing start, the boost max is around 11psi. My understanding is that the build up of RPM/turbo speed is so rapid, in comparison, that the wastegate is overwhelmed. (boost creep) My understanding is that most dynos are done in 4th gear. I think this would be why the dyno generated documents show 7-8 psi max.

Actually, I wondered the same thing. Boost is built up slower in the higher gears, but have not concentrated enough on the boost gauge in third or fourth gear to see what boost i'm hitting on WOT in the higher RPM range. I'm sure you are probably correct. I just didn't know how much boost creep you can expect in first gear. It got fairly close to 11psi today in first gear and I wasn't dropping the clutch or anything.

[madberries]

Originally Posted by DPM

I talked to Casey last Friday regarding boost with the 275 kit and he said it should be about 7 up to 8, no higher.Where did you tap into the vacuum lines for the gauge input? That can make a difference in the readings.

I put a T coming from the existing vacuum line that was going to the VSV on the stock air box. One line going to the recirculation valve, and the other to the boost gauge.

[25psi_Elise_Killer]

i get boost creap in my 1st to 2nd gears and most people who adjust their boost levels do it as the same as a dyno: 5 speeds use 3rd gear for street tuning; 6 speeds use 4th gear for street tuning

[25psi_Elise_Killer]

You should get a Zeitronix ZT-2. Its a compact box with a lot of gauge readings on it: Lambda, AFR Boost, EGT's. Plus you can data log it into your laptop to view your pulls.

[MikeW]

Originally Posted by madberries

I put a T coming from the existing vacume line that was going to the VSV on the stock air box. One line going to the recirculation valve, and the other to the boost gauge.

I think you may want to consider tapping into the plenum. The throttle body may be a bit restrictive and sounds like you're upstream of it. You want a picture of what the engine is getting and not so much pressure anywhere else. And make sure you're not eyeballing that gauge when you slam the throttle body closed. That might tend to show some excess pressure if the blowoff valve is a little smallish or not responsive enough.

[madberries]

Originally Posted by carlover

I know this is a little off topic, but how do you like the kit is it the $11k stage 3? Does the turbo kick in smoothly or is it like driving a stock elise that suddenly gets poked with a branding iron at 6k rpm? Do you know of amy problems with turbo heat or anything like that with tracking the car with this set up? How about high speed on the highway. Sorry for so many questions I've been dying to talk to someone who has one.

Thanks, Joe

Actually, I am running the kit with the Unichip and not their custom ECU. Turbo seems to kick in smoothly for me. I can't really say much as far as turbo heat during a track event, since I have still yet to track it. My car still needs to be tuned so I'm not sure how much input I can provide at this point. I'm sure there are a few forcedfed veterans that are more than willing to provide their input as well. I'll keep you informed though... If I can get my car tuned before April 14th and a few minor details worked out, I'll be able to make it out to the next track event.

[Stephen]

Originally Posted by madberries

Actually, I am running the kit with the Unichip and not their custom ECU. I'm sure there are a few forcedfed veterans that are more than willing to provide their input as well.

The Unichip is good, but the EFI is soooooo much better. I recommend you spend the extra dough on the EFI; I don't think you will regret it.

Forcedfed Veteran #2 or #3

[Bruce]

Originally Posted by Stephen

The Unichip is good, but the EFI is soooooo much better. I recommend you spend the extra dough on the EFI; I don't think you will regret it.

What are you going to do for emissions inspection since the EFI is not OBDII compliant?

[Stephen]

Originally Posted by Bruce

What are you going to do for emissions inspection since the EFI is not OBDII compliant?

Casey set up the wiring harness to go back to the unichip fairly easily, meaing about 2 hours worth of work. So you borrow the Unichip from someone; there are plenty of sources for this, and go back to the Unichip set-up for emissions. Then you return the Unichip to your source and plug the EFI back in.

I took care of my emissions just before I got the EFI, so I am good for a full 2 years. I have no problem whatsoever doing this every 2 years; piece of cake in my book

[Bruce]

Originally Posted by Stephen

Casey set up the wiring harness to go back to the unichip fairly easily, meaing about 2 hours worth of work. So you borrow the Unichip from someone; there are plenty of sources for this, and go back to the Unichip set-up for emissions. Then you return the Unichip to your source and plug the EFI back in.

I took care of my emissions just before I got the EFI, so I am good for a full 2 years. I have no problem whatsoever doing this every 2 years; piece of cake in my book

You're lucky you have 2 years. I have an inspection every year. You will also have to clear all your DTC's and accomplish a successful drive cycle to set the OBDII monitors. Did you ever get a CEL with the Unichip? Others have. And that's a test failure for me - no way around it.

[gkeller]

Madberries

If you haven't already, get your car tuned. The boost characteristics will improve. I'm no expert but it was explained to me like this. When retarding the timing the combustion occurs while the exhaust valve is opening. This allows the continued expansion of gas to do work on the turbine. This increases the boost by driving the turbine harder. By adding timing, more of the combustion occurs in a closed cylinder. This allows for 1) more work to be done on the piston equals more power 2) Less of the combustion energy is used to drive the turbine equals lower boost pressure.
There is quite a bit of timing taken out when using the base tune on the Unichip. My manifold pressures were 9PSI before tuning. This was measured off a vacuum line at the tuners garage. This was in 4th gear and closely mirrored my installed boost gauge values. My boost/temperature transducers are in a modified section of aluminum tubing placed in line with the BOV. Because of this, I see spikes probably related to throttle closure. These spikes are only seen on the max pressure readings but are not seen during regular operation. However, I think this setup closely predicts the manifold pressure. This was supported at the tuner's garage.
After tuning, the max pressure was below 7.8 PSI using the tuner's method of measurement of manifold pressure. All minor drivability issues are now resolved but still have CEL.

[madberries]

Thanks for the info... I really would like to get it tuned as soon as possible. Unfortunately the guy at Stage 6 motorsports is off tuning a car in Europe, so I will have to wait until he gets back to get it tuned.

[madberries]

Also, what is the CEL you are having? I fortunately had no CEL when I first turned the key after the installation. But I did manage to get multiple misfire codes 2 weeks later. This turned out to be due to an injector clip popped off for whatever reason. I snapped that back into place and wiggled the others to make sure they were secure, and it was working fine after that (zero codes).

[Bruce]

Originally Posted by gkeller

All minor drivability issues are now resolved but still have CEL.

Your CEL came back? Is it the same DTC?