HarrisRacing

Back from the dead. I confirmed 300 rpms earlier spool with exhaust retarded -4 deg (CRANKSHAFT degrees), and Intake cam advanced 6 deg (CRANKSHAFT degrees) on a 2.75L stroker w/ BW 8374 EFR .92 turbo with very little if any loss on top end. Gained MASSIVELY from 4k to 7k rpms (no kidding 30+ rwhp across the board). Same boost pressure (20 psi) on pumpgas.

Note to all. Finally moved my cam gears on the dyno. Spent 4 hours there yesterday (on a dynocomm inertial - which will soon be eddy brake). I now see what a V-cam would do for you. Moving my Poncam A's closer together (ie-more overlap) yielded undeniable tq gains with no appreciable drop in top end power (my 3" exhaust could be holding me back). I think it liked 8 total degrees of CRANK overlap (2 notches off from '0' on each cam) the best (Advanced intake 4, Retarded exhaust 4), but we did run add another 2 deg (crank) to the intake to bring it to 6 deg intake advance and 4 deg exhaust advance and this is where it stayed (for now). Super choppy idle now, but damn this car pulls like CRAZY now. makes 3 more psi boost at 4k rpms. When I compared 20 psi runs with cams set at 0 the tq goes to the stratosphere. Look at the differences from 4500 rpms to 7k! At 22 psi high number is now 653 whp and 515 wtq but boost control was shakey on these runs (oscillating from 22 down to 18). It is making 300 WHP at 4k rpms on 20 psi...on 93 octane pumpgas! This is my 8374 EFR .92 IWG on a stock-bore 79mm BC stroker FYI.

I have found my car spools at lower rpms on the street consistenly over what it does on the dyno. Dyno makes it seem laggy when compared to street logs. But I don't have access to a load bearing dyno yet.

I've got a few posts on the hypertune. Similar. Get ready for a pita in the engine bay. Search my name.

I do have Tomei head restrictor, Greddy Sump (Which the Tomei tells you quite clearly you shouldn't run in some of it's settings without a larger sump), and N1 block (which has larger drain ports back to the pan), also mine's baffles and rear "drain" if anyone cares about that anymore. And I'm on the Fluidampr balancer (seems really nice). Also yes Haltech...I hit the 2 step limiter when launching everytime but if I spin the tires the car racks out so fast in first that it hits the limiter quite quick on top. It IS a soft touch limiter though which at least isn't as hard as a hard cut. I'll bump the revs to 8500-8700 and use Haltech to output a shift light and try to just stay off of it. But yes thanks for the info. Also I do have the Haltech reading oil pressure and use the "engine protection" feature to put it in limp mode when it senses oil pressure low or high out of range. I'm not sure the guy was spline drive, but I ran across the thread (not on this forum) after someone asked me if I had converted mine to spline drive. And yes BC billet stroker crank. Engine runs really smooth with the balancer, crank, heavier nismo coppermix, etc. Thanks!

Tomei oil pump failures I tried searching but ran across the spline drive oil pump conversions and hadn't really heard bad press about the Tomei oil pump until then. I read about ONE failure so far and the thread did not provide Tomei's resolution to the pump issue so I'm curious if this is actually a potential problem or not. I have a Tomei pump and am curious if anyone has seen one broken and under what circumstances. I'm limiting my car to 8k, but I do bang the limiter quite frequently and was just thinking about going a bit higher soon. Some say the cause of failure is oil cavitation from temporarily starving the pump (which means a dry sump would be the only real cure), and some say it's simply the 2-flat-drive stock pump orientation that kills oil pumps. I'm looking for actual evidence if possible because I'd like to live the rest of my engine's life in a happy state of knowing the chances of oil pump failure are very slim. Patrick

Took my son (15) to a drift event this weeked, pulled the fuse and had some fun! Rear diff is a bit worn...and I need to do all of the bushings anyway.

Installed all of it yesterday. Getting those motor mounts in was a total PITA. The fan shroud, however, was easy (didn't even need to remove fan or belt). Nismo Engine mounts Nismo Transmission mounts New Nissan fan shroud Used axle (New CV boots) New fan shroud Cranked the car just to get it running. Ran no problem but I need to fill the front diff fluid level today and then I can drive it. Needed to lower the subframe on each side while jacking engine up to get mounts in - managed to do this with axles in and most components still hooked up but was PITA running pry bar and all by myself while wedging the mounts into place. My advice now is if you are EVER getting at your mounts or removing/installing the engine do the nismo mounts right then!

Installed New boots and such on a used axle and put that in the car, just waiting on the nismo mounts and fan shroud.

Older ones but they looked and felt good. Strane to me where they both sheared where they are bonded to metal. Don't have a video of this launch but do of others. I was just doing the burnout this time doing some testing.

Full tilt launch on street. Broke immediately. I'm on front nismo LSD so it goes pretty good but the only thing i can figure is the mounts sheared then the motor jumped and then the axle went. Yours looks insane! Wow how did you do that?!

Since everyone likes pictures of broke junk! Also very thankful the turbo hit the strut brace and kept the motor from coming out of the hood!

Roger that. Ordered them

Gross. Broke a motor mount on launch...not good result. Broke the driver axle, pushed the whole motor down and towards the passenger side which destroyed my fan shroud and pushed my turbo into my hood damaging the under support (flattened it) and slightly bulged the hood. Yeah...don't trust factory mounts. I'll be welding these solid now.

It's more like: -7 are like N1 stock turbos. Nice upgrade with not much change in spool capable of running more boost reliably. -9 are a step up from here but don't come with actuators so end up more pricey than -7 or -5 -5 are pretty serious turbos and come with the resulting lag (5k rpms start powerband) -10 should not be used IMO. Way too much lag and much better other alternatives. Streetcar that will only see pumpgas -7 all day. Streetcar that may turn boost up on E85 -9 with good aftermarket high pressure actuators Race or track car looking at 500+ whp (or a stroker or RB30 car) -5s.

I'd be willing to bet with the smaller turbo honestly not a whole bunch. Smaller diameter runners can actually lead to more spool on smaller setups.

Updated Dyno run for my car from the other day. Now solid 20 psi, 3-4 more deg of timing and no knock. BIG power increase! Umair I'm catching you up top with only 20 psi. Gonna run the 1/4 again (hopefully this weekend) and see what she does. Should be 10's on pump 93 octane.

Updated dyno from yesterday's tuning session. Increased timing from factory Haltech up 3-4 deg. Also increased boost from 17-18 up to a pretty solid 20 psi. BIG changes in HP. This 8374 LIKES THE BOOST. So the car is up about 50 whp over last time at the drags so it should be 10 sec pass on street tires and pump gas this time around. Also they just finished two E85 stations around my house so get ready for REAL power soon! Getting FUN! Here's comparison to last time at the dyno. Also on this dyno a stock C7 Z06 put down 571 HP/576 TQ so with 14% drivetrain loss it's right at factory claimed 650/650 for comparison purposes (for whatever that matters). Build is 2.75L BC Stroker crank on stock bores Tomei Poncam A set 0-0 ported head BC SS valves Hypertune V2 CP valve-relieved pistons BW 8374 IWG .92 turbo 6 Boost Divided T4 manifold

*****EDIT********************************* This dyno was found to read 4.5% high after numerous stock cars were dyno'd on it and other dynos. The overall baseline was adjusted down and these dynos should have yielded only 601 whp. The later dyno where I played with cams has the 4.5% removed already. ******************************************** So my buddy bought a dyno from a shop that I previously dyno'd my old Supra on (video HERE). It did 366 rwhp at the time (downpipe and boost controller only). This was owned by a company called LETHAL RACING and if you look the dyno does read about what you'd expect to see by normal standards since their stock C7 Z06 did 571 whp and 576 tq which is right there at 650/650 factory rating after a 14% drivetrain figure (see stock C7 Z06 dyno HERE). So my buddy now owns this in his shop MAD HATTER GARAGE and asked me to come shake down the dyno with him. Well I finally got a chance to do a little more tuning and here are the numbers from last night. It was a nice cool 68 deg F and I ran the car the whole time it was on the dyno so it never really got a cool down time. BUT I was able to get 2 more deg of timing in it and get a more consistent boost curve which resulted in about 50 more RWHP than before on pumpgas!! I'm going to convert the dyno pulls to excel so I can have my boost and AFR from my Haltech logs, but so far it looks like it's capable of 629 rwhp and 481 tq on pump at 19-20 psi. This turbo REALLY makes big changes on boost because the dip on the low end was where it was only 17.8 psi and I got it to sustain around 19.5 (which isn't even 2 psi) and the car (with no timing changes) made 40 more rwhp there. If the turbo keeps acting like this it will be insane at 27-30 psi!!! I did try 20.5 psi, but it would produce a touch of knock in places so I decided to leave it at 19.5 command. Video of pull here

I'll test it! Send me one geoff!

Finally solved my power steering belt issue. I ordered the Fluidampr harmonic balancer for a R33/R34 since I have the later long-snout crankshaft in my car. This is not correct. The front bolt-on pulley of the R33/R34 Fluidampr balancer is 1/8" shorter than the earlier model to match up the power steering pulley location on the later model single-vane R33/R34 power steering pumps. The front pulley is exchangeable and the correct one FOR YOUR POWER STEERING PUMP should be ordered if you decide to go this route. Now the PS belt stays on just fine at high RPMS.

I'm leaning toward something kinked with fuel lines in tank. I replaced the factory hoses the first time i did my pump and they didn't hold shape and kinked. Went back with factory and it worked fine after. Does your fuel pressure hold when you shut the car off?

I don't see how an fpr could cause a drop in pressure on top unless it's plumbed incorrectly. Send us some pics of that first so we can make sure everything is plumbed correctly. Rewire is almost mandatory on these cars. Mine picked up a lot of flow with new wires. I'd be worried your pump isn't genuine

I've read the N1 oil pump is better...but I can't confirm. I was not convinced enough to go with it and instead went with Tomei $$$$$$$$. The N1 water pump just works better at high rpms...not necessarily for a streetcar, but I am running it on my streetcar which sees 8250 rpms every time I drive it and I live in a very hot climate with no issues on the KOYO radiator. It reduces cavitation at very high rpms. Factory or N1 Cams should work no problem in your motor, just get your shims correct for valve clearance to make sure you are not losing power and are not going to hurt the motor. Indexing the cams closer together (cam gears move AWAY from each other, but CAMS move toward each other increase the valve overlap which means as the piston is pushing exhaust up out of the cylinder through the exhaust valve, the intake valve will start to open slightly before the exhaust valve is closed... This results in a few things: 1) At lower rpms the car will run slightly rougher and have slightly less vacuum because you are diluting (slightly) the exhaust and intake streams. 2) At midrange rpms where the exhaust back pressure in the turbine is less than boost pressure, the car will make more torque and power. This will make for a "punchier" feeling car. 3) At high rpms when the turbine starts to make more backpressure than the boost pressure the exhaust will reduce the ability of the intake to inject boost into the cylinder. This means that you will lose some top end power at high end. So basically when you move the CAMS closer together by increasing how much the valve timing overlaps, (by either retarding exhaust cam or advancing intake cam) you "tighten" the powerband, but you make it more torquey. When you move the CAMS further apart you make the car run smoother around town, and make more power on top end, but it will not be as agressive in the mid-range. I think the N1 setup was for the N1 turbos, and for road racing. They were probably increasing mid-range response because this is what you need in road course racing to pull out of turns. Yes I think if you retard the exhaust cam 5 degrees on stock cams, you essentially turn them into R33 N1 cam timing.

Correction. My 18-19 psi was 123 mph and 122 mph respectively and this is not 20 psi yet. A better hookup/launch pretty much always leads to lower mph due to less time to accelerate - It's Newton's third law postulate on drag racing (joke) But yes guys I see what you are saying...a 505HP C6 Z06 is almost the exact same weight as my car and they run mph almost identical to mine and it's well known they run about 440-450 whp from the factory so can we assume my dyno was about right at 460whp seeing as I have less torque than the big block V8 has? So I guess we need to compare to turbos that will make equivalent power and times at these boost levels and see what we can trend. Perhaps the .92 IWG 8374 acts "small" on an RB26 and that's why it spools so low and feels so responsive in the low end? Sure i could see that. In my case of the car still not being 100% sorted and still almost touching 10's on pumpgas, it could be the case that I have too much cam overlap and I am blowing my boost out of the exhaust (another thing i need to try next time I dyno). Either way we greatly welcome ACTUAL comparison data and logs from others so I am going to push the ball back into you guys court to provide that because I have asked several people several times to give us some data because as of now my car is: 1) Touching on 10's in the 1/4 and 2) is responsive enough to win FTD in autocrosses. That alone should tell you something about the performance capability on pumpgas. And I'm willing to bet the 9180 is almost a better choice if you need all out power...I'm reading that I'll only lose 4-500 rpm of threshold but it's a 1000HP turbo all-in. Soon I'll have the speed gauge and that will tell me where I'm at turbo speed limitation wise...who knows it may tell me I'm only using half ofit's capabilities...but then again if i had -5s or a Precision we'd never know anyway.