Great job on DIY. I followed your thread on evom. There is nothing wrong with working on your own vehicle.

 

This is amazing stuff. Love to see quality DIY work on a GT-R

 

James is the man. He gave me an idea of what he does for a living. Now I feel like people are watching my house since he left yesterday lol

 

Thanks for the ride and your Alpha 6 is one sweet GTR.

 

I took an hour this evening to tune the car for 17psi. I think this was stated, but I started with the Cobb Beta Stage II map for 93 octane and the only current mods are midpipe. I want to thank Doug at WeaponsGradePerformance and Chris from SBD for spending 10min to answer a few questions since I have not tuned a MAF setup and had a few questions. Once they explained the map relationships it was cake to tune. For anyone considering AccessTUNER Race I would highly recommend spending the $700 if you plan on a staged build.

After the initial run, the STFT's were looking good, but the car was seeing a bit of knock. I was actually glad to see knock so I don't have the play the game of adding timing to see knock and then backing off. Below is the log...

Since the timing map is RPM vs Theoretical Pulsewidth I logged the two to understand where within the map I needed to make changes. A quick change of the timing map in the affected area and the car was consistently running clean with ZERO knock. I personally don't want to see any knock even though you can see minor knock without reverting to the secondary timing map.

I will likely install the pumps/injectors/intakes next weekend and hope to follow up with the modification of the exhaust. After that I will head to the dyno for a baseline run.

 

Glad to hear!

Enjoy the car

 

Mad props to this man. I we need more like him trust me. When people like him start to debunk old theories and show that things can be done for cheaper everyone wins including vendors. Your probably gonna say how are vendors winning? They may not make as much off of their individual parts sales but they will more then make up for it volume wise and installs because people will be able to afford both instead of just one or the other.

 

I was thinking more of in the line of allowing the average Joe Bloe (me) purchase those performance parts...in the end it is still a Nissan...an exhaust is still an exhaust...designed to take the by-product of combustion out of the car...

Pikes Peak R35

 

Due to weather my business trip was cancelled for today so I was able to install the Denso 265lph pumps this evening. There are plenty of threads detailing the pump install so I won't repeat this topic. Install took about 2hrs total taking my time, but is much easier if someone can hold the pump assembly as you unfasten the clips holding the pump assembly together. I will make one contribution to the topic by providing advice for the DIY folks.

When you reinstall the pump make sure you remove the o-ring for the pump outlet from the housing. I used a piece of welding rod and bent the end to a hook to pull it out. Make sure you seat the o-ring on the pump when installing or you will likely experience issue with the o-ring sealing on the pump.

I would also recommend that you attached the pump filter to the bottom of the pump before reinstalling as it makes it much easier to install the filter prior. I also slightly lubed the o-ring before reinstalling.

The car took a few seconds to fire up but once it did everything was fine. I took it out for a spin and checked STFT and I was able to verify pumps were working well. The STFTs at idle are showing too much fuel, which is expected when running larger pumps as it will typically increase the baseline fuel pressure. I hope to install the ID1000cc's this weekend with intakes and retune.

 

My new silicone couplers have not arrived so I went ahead and installed the intakes as well as the ID1000cc injectors. I switched to the Cobb Stage III map and transferred the revised timing map from the previous tune. The car fired up with no issue, but I did have some fluctuating idle that was fixed by adding a bunch of fuel at idle. I was only able to make a few pulls at 15psi, but the STFT's were in the 0.96 range so the OTS map was fairly close and will not require more than about 1hr of street tuning to dial in the MAFs. The next step is to modify the stock exhaust, which I hope to start next weekend.

 

Nice to see you making parts for your GTR. I followed your thread on evom. Cant wait to see more progress.

 

I took a break from the EVO to put time towards the GTR. I did just pick up the wiring harness and programmable transmission controller for the W4A51 auto tranny swap and I will be getting the paddle shifter on Monday. I hope to have some updates on the EVO next week just showing all the hardware. Minus the intercooler setup, I should have the GTR completely in 4-6 weeks.

 

I decided the pull the trigger on TCM with Cobb and put down $400 for the license. My car has 6100 miles and had never done the clutch relearn and I wanted to swap to LC5. Software install went well and I don't feel a huge difference in shifting, but the trans seems to make more noise with LC5 vs LC2.

I spent some timing refining the MAF curves, but I really need to get my wife to drive the car so I can tune the MAF realtime when it is in steady state at various MAF voltages. Regardless, the tune is doing well so I decided the up the boost and currently have it set to 18psi with zero knock count. If my wife permits I am going to do the exhaust mod next week, which I hope will only take 4-6hrs.

 

lol "if my wife permits"
been there my friend

 

Nothing as exciting as fabricating exhaust on your back. Started by jacking up the car with the rear center point and then setting up jackstands.

Cut the rear exhaust so I could focus on the forward section first.

Started welding the pipe starting from the front and working back. I use Solar Flux B instead of argon purge because it is easier and just as effective.

Making progress.

The vband uses male female for better seal so you have to clamp them together when welding or it is impossible to get back together.

More progress

Merged the 3.5" exhaust into the rear stock exhaust.

Almost done, but done for now...

 

Looks good man

 

Yay...no more $4K+ exhaust systems...

Pikes Peak R35

 

Yay...no more $4K+ exhaust systems...

My out of pocket cost for the exhaust modification is ~$200, which includes the following:
- ~5ft 18g 321SS 3.5" pipe
- SS 3.5" 2-bolt exhaust flange
- SS 3.5" vband assembly
- Remflex gasket

 

Dude...awesome tread! You are an inspiration.

 

Nice job!

 

I forgot to explain the rationale behind this mod. The outlet of the Cobb Midpipe is 3.5" and it transitioned into the factory 2.75" exhaust, which splits at the rear of the car to two 2.4" pipes. If you take the cross sectional area of two 2.4" pipes it equates to single 3.4" pipe. Just by swapping this short section of the factory exhaust I have a high flow exhaust for a fraction of the cost.

 

Keep on trucking...maybe one day ill be you first customer...

Pikes Peak R35

 

make me the second
loving that exhaust mod
can't wait to hear what it sounds like

 

Exhaust is finished, but I am waiting on delivery of the the new gasket for connecting to the midpipe. I started the car for a few seconds and it sounded good and not noticeably louder than the full stock exhaust. I should be able to give a better review on Saturday when the car is back on the road.

 

Are your DP on yet?

 

No, stock catted dPs

 

Just a thought...there are likely a lot of shops that have stock exhausts sitting around and are considered scrap. Perhaps a shop can make a jig and sell a modified stock exhaust like the one I made as a lower cost option vs full aftermarket. I have $200 in materials and ~8hrs in fabrication on my back and in my garage so it was less than efficient. A real shop could do this more efficiently so $1200 would be a fair price. I am confident this provides an increase in hp, but it would be good to quantify vs. stock.

 

Just a thought...there are likely a lot of shops that have stock exhausts sitting around and are considered scrap. Perhaps a shop can make a jig and sell a modified stock exhaust like the one I made as a lower cost option vs full aftermarket. I have $200 in materials and ~8hrs in fabrication on my back and in my garage so it was less than efficient. A real shop could do this more efficiently so $1200 would be a fair price. I am confident this provides an increase in hp, but it would be good to quantify vs. stock.

umm, for $1200, you can buy a complete 90mm stainless catback from China.....trust me, I've done it.

http://www.alibaba.com/product-detail/Exhaust-system-titanium-automobile-exhaust-muffler-_265862796.html

 

Wow big props to a local charlotte guy

 

Thanks!

Gasket arrived today so I installed during lunch and drove the car. I noticed little to no change in exhaust sound by removing the 2.75" pipe and replacing with the 3.5" pipe, which is good because I don't want the car to be obnoxious (yet). This should definitely help the car breath on the topend so I am happy with the outcome.

 

Nice work all the way around, man!
I'm a big DIY'er as well, it's very satisfying to see a successful project through to completion!

 

^ Thanks

The next step is to spend this week tuning the car extensively and then I am headed to the Dyno for a baseline tune. I will then swap the Curt Brown ported inlets and intake manifold for a before/after.

 

I took about 1.5hr this morning to start tuning the car before sticking on the dyno this week. I will likely play around with timing leading up to full boost, but full boost timing has already been adjusted since I removed timing due to slight knock. My focus for today was intake cam timing and its affect on boost response and topend power. Since my EVO IX has variable intake cam timing I am used to tuning this with my Haltech Platinum Pro PnP and the tables are identical in terms of tuning.

I started with the baseline Cobb Stage III intake cam advance map and created a baseline response. I also created duplicate maps as the baseline and only changed the cam advance map using alternative maps from the Cobb Stage II and Cobb Stage II Beta. I used Virtual Dyno as well as log view to interpret the response of changes made. After several logs I determined that the Cobb Stage III intake cam advance gave the best boost response and generated the most torque in Virtual Dyno below 4K rpm. The car makes 18.4psi @ 3600rpm in 3rd gear after car is good and heat soaked and 18.4psi @ 3400rpm in 3rd gear when car is cold. Above 4k rpm I noticed the Virtual Dyno showed the Stage II map made more power, which shows that intake cam advanced needs to be ramped out starting at 3600K rpm so I merged the maps together for a more optimal balance of spool and topend power.

Below is the boost response of the Cobb Stage III map vs Cobb Stage II map.

Below is the Virtual Dyno results of the Cobb Stage III intake cam advance map vs my hybrid Cobb intake cam advance map. You can see that up to 3500rpm the hp/torque are the same, but by ramping out cam timing the car pics up topend hp/torque.

Finally, here is the interim intake cam advance table I currently run. I need to investigate whether I can run negative advance numbers on the topend in this map without damaging the engine due to piston-valve clearance.