2.8L Roe, GG heads/cam Build thread
- Thread starter speedracervr4
- Start date
speedracervr4
Enthusiast
Car is with Sean still. He had it on the dyno and at 8lbs with no **** it made 637rwhp/625tq. He tried adding **** and it lost power so he has to do some troubleshooting to see why. The cam seems to have less low end tq, but it continues to pull power at the higher RPMS. Once he figures out the **** issue he will change the pulley to the 10lb one. We decided to go with the SCT and VEC together.
@5500 rpms the Injector Duty Cycle is at 100%, so he's changing the injectors. We also decided to cut out the pickle from the belanger headers to help flow. It has been a long project and I hope to have the car back soon.
@5500 rpms the Injector Duty Cycle is at 100%, so he's changing the injectors. We also decided to cut out the pickle from the belanger headers to help flow. It has been a long project and I hope to have the car back soon.
EllowViper
Enthusiast
Last summer with my 2.8H running the Weaver overdrive pulley and 2.5 blower pulley I made 16 PSI of boost (indicated) on a mildly ported ROE manifold. I was running about a 800ml shot of 50/50 W/M in the intake tubes and 18 degrees total timing. I made just under 700 rwhp and 800 tq without spending a lot of time dialing in the tune or messing with the W/M mixture. The max tq came on at 2000 RPMs so the set-up is a real stump puller. I have since backed down the boost to 10 PSI and opened up the ROE manifold to the max possible. I have increased my W/M to around 1400ml on a progressive controller with both a pre and post blower nozzle set-up and am experimenting with a 100% methanol shot. I need to redyno the beast to see if I can add some timing due to the changes I've made. Regardless, solid mid 600+ rwhp is pretty common with anything 8 PSI or greater. Beyond 8 PSI or so, you are fighting parasitic blower drag and airflow issues. I think Kenne Bell estimates our blower drag to be somewhere around 150hp at the speeds we are spinning the blower.
speedracervr4
Enthusiast
My guess is the high flow cats and pickles are hurting my power somewhat. I would love to be around the 700 mark, but in the end I'll trust the tuner with the results I'm given. I've read a few guy's threads about adding adding a bunch of timing to make big numbers with the Roe, but I'm sure Sean/Torrie would rather not have the engine become a boat anchor. I believe with the **** shot we're at max timing at 21.
I have two nozzles(375ml &675ml) in my intake tubes with a 50/50 **** mix. The bungs that JMB welded on to the tubes don't allow the nozzles to be in the direct airstream because they can't thread in far enough. Maybe it's not allowing the nozzles to have a good spray pattern? I was also thinking about switching the nozzles to two 375ml to see if it makes a difference.
Thanks Ellow for answering my questions from the alley, I appreciate it.
I have two nozzles(375ml &675ml) in my intake tubes with a 50/50 **** mix. The bungs that JMB welded on to the tubes don't allow the nozzles to be in the direct airstream because they can't thread in far enough. Maybe it's not allowing the nozzles to have a good spray pattern? I was also thinking about switching the nozzles to two 375ml to see if it makes a difference.
Thanks Ellow for answering my questions from the alley, I appreciate it.
speedracervr4
Enthusiast
You can see a picture of the "pickle" in this thread towards the bottom. http://forums.viperclub.org/threads...ders-for-my-supercharged-GTS?highlight=pickle.
It's an obstruction and Sean had mentioned he and David Weaver of ART had noticed gains by removing it on F.I. motors. I should have thought of it during the build instead of paying someone else to do it.
It's an obstruction and Sean had mentioned he and David Weaver of ART had noticed gains by removing it on F.I. motors. I should have thought of it during the build instead of paying someone else to do it.
Speedracer
Thanks for the reply, I figure that's what you were talking about. I did not have a name for it LOL, I was thinking the same thing, and said to myself, why would he put it in there in the first place. (Had the grinder, welder, tools ready to cut it out). Why not give him a call to see what's the deal. I know it cost him more to make the header with it there so what's is thinking..Looking at it it seems to be very restricting, but after talking to Lou, I understand what his thinking is. ( think of it this way, if i said can you speed up the rate of water come out of a garden hose by covering part of it with your finger?) I think more people would said no, but you can when you cover part of it with your finger. I really would give him a call first befroe removing it. I know my personaly experience with exhaust flow. I pick up .4th in the 1/4 mile by hadding a muffler to open headers ( race car) the only change I made to the car after a buddy said to try it. I also know that there are some muffler on the market, that flow more air that a straight pipe. Here is a link: of the XR-1 race muffler.
http://www.borla.com/products/xr1.html
I would call belanger just to hear what he as to say.
Last edited:
speedracervr4
Enthusiast
Thanks for the heads up, but they have already been removed and the new injectors are also in. Sean just needs to figure out the **** system issue. I can understand leaving the pickle on an NA build, but I'm not so sure about a boosted car. Sean has seen gains by removing it and it's too late to turn back now,lol. I've also heard you can order the headers without the pickle as well.
Last edited:
Speedracer
Not a prob, I understand. If you have the time give him a call just to see what he as to say just out of curiosity. You are right he does sell the headers with and without the "pickle" but see what he as to say about that. Your car is in good hands. Keep us posted.
Not a prob, I understand. If you have the time give him a call just to see what he as to say just out of curiosity. You are right he does sell the headers with and without the "pickle" but see what he as to say about that. Your car is in good hands. Keep us posted.
speedracervr4
Enthusiast
Sean/Torrie are done with the tuning for now. Dry with no **** @9.6 LBS of boost the car made 633hp/629tq. With **** the car made 672hp/655tq. Both the dry and wet tunes were done with conservative timing maps. We probably left some HP/TQ on the table by not being aggressive with the timing, but I'm fine with a safe tune. I'm sure the high flow cats could also give me 10-15hp, but I'll see how it runs first.
I may relocate the IAT sensor because Sean had mentioned it wasn't getting good airflow where it is located in the JMB airbox. The metal box may have been heating the sensor up as well. It was giving them issues while tuning. Maybe with the hood closed the naca duct will direct airflow over it better.
These are not huge gains, but I'm still really glad I did this project. It's a great learning experience tearing your car apart.
I may relocate the IAT sensor because Sean had mentioned it wasn't getting good airflow where it is located in the JMB airbox. The metal box may have been heating the sensor up as well. It was giving them issues while tuning. Maybe with the hood closed the naca duct will direct airflow over it better.
These are not huge gains, but I'm still really glad I did this project. It's a great learning experience tearing your car apart.
99 R/T 10
Enthusiast
Do you still have the stock cats in place?! If so, with the Roe, they are robbing you of 30+ HP. Cut them out and retune.
speedracervr4
Enthusiast
No, I have high flow cats. They looked fine and are intact. I'm thinking they are robbing me of about 10-15hp. I would rather have the car tuned with them and then remove them later than have to add them back on the car and not have a tune for the added restriction.
Last edited:
speedracervr4
Enthusiast
It has been like that since 2006.... I may ditch them and go with a 2.5" pulley in the future.
speedracervr4
Enthusiast
Figured I would share some info on the JMB intake and some dyno sheets. The JMB box was hitting my hood so I just trimmed it with some aviation 90 degree pin snips and a die grinder/sander. The IAT sensor is not in the best position. Like mentioned earlier the location on the air box was causing it to heat up from the heat coming off the radiator or radiant heat. Looking at the box there is a drain hole directly below the sensor that I'm sure lets hot air (from radiator) come in contact with the IAT sensor. Sean actually move it from the holder and hung it over the edge and the car picked up power with out any adjustments. I recently relocated the sensor into the passenger side intake tube. Not sure if it helps with HP/TQ, but it won't hurt.
The SCT/VEC combo works great. The car is very smooth and stable. The only issue I have is the idle will sometimes hang up until the car comes to a stop. I'm working with Sean to fix the issue. The VEC is used for individual cylinder fuel trims and **** spray. I wanted it removed from the system, but cylinders 9 and 10 were getting fouled out with just the SCT.
I cut both sides approx 1/8-1/4". You can see the old IAT sensor location.
Used a step bit that went to 7/8" and a grommet to relocate the sensor into the passenger side intake tube.
You can see the drain hole at the bottom of the box.
The SCT/VEC combo works great. The car is very smooth and stable. The only issue I have is the idle will sometimes hang up until the car comes to a stop. I'm working with Sean to fix the issue. The VEC is used for individual cylinder fuel trims and **** spray. I wanted it removed from the system, but cylinders 9 and 10 were getting fouled out with just the SCT.
I cut both sides approx 1/8-1/4". You can see the old IAT sensor location.
You must be registered for see images attach
Used a step bit that went to 7/8" and a grommet to relocate the sensor into the passenger side intake tube.
You must be registered for see images attach
You must be registered for see images attach
You can see the drain hole at the bottom of the box.
You must be registered for see images attach
speedracervr4
Enthusiast
Dyno sheets. All runs where done in the Hot/Muggy Florida weather.
Dry Run.
Water/****.
Cool dyno pics after a long day.
Dry Run.
You must be registered for see images attach
Water/****.
You must be registered for see images attach
Cool dyno pics after a long day.
You must be registered for see images attach
You must be registered for see images attach
99 R/T 10
Enthusiast
That's not bad on 10lbs of boost. What was the A/F?
Also, are you using the DW crank pulley?
Also, are you using the DW crank pulley?
Last edited:
speedracervr4
Enthusiast
Low 11s for A/F and it has a stock crank pulley. I only wanted 10lbs of boost and the 2.65" blower pulley got me there.
EllowViper
Enthusiast
Fun stuff isn't it!!!!! I was terrorizing the central Florida backroads yesterday doing some long pulls in 5th at WOT. Hits 170 @5500 RPM pretty darn'd quick with 10 PSI boost, big w/m charge, and AFR's dropping in right at 11.9. I really like running w/m for so many reasons. Mike, I should get that f'ing DW pulley back from you!!! LOL.
