OK. I have a friend that has a 1990 300ZX naturally aspirated. well he is trading it in for a twin turbo 300ZX this christmas. now i like his car i must say i think nissan did a good job with this car and while the twin turbo only has i think 310hp i know i shouldnt have much to worry about ( i have the LT4) BUT!,... he knows a LOT about turbos. as soon as he gets it he is putting a complete exhaust system on it and putting in a boost controller, and reprogramming the computer. now what worrys me is not the fact that he will be putting out well over 400hp but the horsepower combined with the fact he has dual overhead cams and will have a redline of about 7600 and the fact those 300's have an insanely high rear end stock like about 4.01! so not only is he going to have a hp advantage on me but even if i could match his hp he is still going to be shifting a lot later than me and have that rear end working for him in the acceleration dept. my question is this..... i want to rebuild my LT4 eventually so what options do i have in high revving cams? i just found out about these hydro rev kits and that sounds liike it may be a potent weapon against those pesky DOHC engines. can anyone else help me out with this? i really dont care about gears im more wondering abo9ut cams and such. thanks

 

You will find the solution to beating your friends Nissan here.
http://www.procharger.com

 

WOW! 65% increase on my stock LT4 would be close to 500 at the wheels although im not sure how my 10.8:1 compression ratio would like forced induction!

 

I'd wait and see what his really does after he gets it and tweaks it,then go from there.I would stay N/A if I were you.Ported heads,good cam(cc306 or there abouts)long tube headers,with the right tuning,and your looking at 400+ rwh.

 

Well if you just wanna beet him on the occasional run then get nitrous, if you wanna feel good about it and sleep well at night thinking that you have a fast car, then have the heads comletly ported some stageIII, get a bigger TB the CC306 cam mentioned above is ideal for a 400+rwhp aplication. Also get a a set of luge tubes, good exhaust, and a new clutch :D, if you really wanna go hardcore on it, after all of this get a stroker kit. 383-396-406 :yesnod: :crazy: :smash: :cool: The vette is still the King. :thumbs:

 

Keep in mind that as soon as you dump a whole lot of time and money into the Vette....he'll turn the boost up another pound or two. Many of those cars seem to have a LOT of margin built in and guys just pump them up a little at a time as required. If you want to consistently beat him, you have to make sure you can exceed the amount of power he can easily get to and force him to dive into the engine. Then it becomes a matter of who has the biggest checkbook.

At Gateway International two weeks ago during a PCA event, there was a '97 TT Supra in my run group (a nice guy btw). Looked, sounded, idled like it was stock. He claimed to be over 500hp and judging by how fast he passed me...I think he was underestimating his power. I'm 342hp to the wheels, so about 400 at the crank. There are two points to this story 1) It's very easy for your buddy to put out some serious power and 2) You WILL lose some amount of low rpm, part throttle driveability by going to a long duration high rpm cam

Not trying to rain on anyones parade, just trying to lay out the facts.

 

WOW! i am leanering lots of useful information here! BTW i DO want to stay naturally aspirated. and yes i realize i will have to dive pretty deep into the engine when he can just up boost. i am really curious about cams for the chevy small block. i consider myself somewhat knowlegable in most other parts of american pushrods but just no cams. how high are you ppl on this board running your redline with after market cams? is it the higher the redline the lopier the idle? if you have a high redline does it idel faster or slower and want to die? these are some of the answers im looking for

 

The lopey idle has nothing really to do (directly) with the rpm characteristincs of the cam. The lope is due to the degree of "duration" of how long the valves are held open. The longer the duration, thee more noticeable the lope.

Also, remember, you need to beef up the bottom end of the motor if you are going to be increasing the "redline" any appreciable amount. LT1's don't really care for rpms much over 6200. LT4's are much more tolerant, as long as you don't get crazy and start shooting for 7 grand plus.

If you want to cut down on the lope of a long duration cam, you can increase the idle speed. Personally, I LIKE the lopey sound. It gives the vette "personality".



[Modified by MagikDraggin, 9:39 AM 8/27/2003]

 

i love the lopy sound as well as long as it doesnt die from idling to low. i understand you have to have a bottom end to match a cam and when i finally DO rebuild i want a completely forged bottom end so i can run a pretty high compression and possibly a bit of nitrous if i want. i only want a cam that redlines at 7k not 9 or 10 grand like stock cars on the winston cup series. they sell cams in summit for chevy smallblocks that make power up till about 7200-7300. so i think if i get a stout bottom end and a rev kit i shouldnt have a problem getting a cam that will make decent power up till 7k

 

I have the hotcam kit, and I swear I stop pulling as hard after 5000 RPM.

I wish I had a slightly higher RPM cam....

Peak HP on the dyno for me is 345 at 5900 RPM.../ 353 rwTQ

With a 100 shot nitrous I get 430 rwHP / 474 rwTQ.

By the way, the 300 ZX TT arent threats. I remember an orange Stillen version that Road and Track tested somewhere around 91 to 92 -era.

I know that Road and Track never posts the best times, but I was not impressed with the improvement in performance it made....regardless of how much HP it had.

Some turbo cars are dyno/highway queens. You, with the torque, will beat them off the line. By the time their big turbo spools up and starts making serious HP you will be halfway down the track.

They will be catching up on you, but you're already there.

On the highway is where you need to watch out. DOHC/24v combined with a turbo is scary fast on the highway.

Dave

 

I think after he tweaks it you can still take him. They are only ~14.0 1/4 mile cars.
Don't underestimate your LT4.

I found this on the internet:

"In May 2001, I bought a 1991 Nissan 300ZX Twin Turbo from an individual near the Clemson campus. The car is all stock right now, but it will likely be upgraded to an as yet undetermined level at some point.
Stock horsepower is set at 300, but the minor "stage III" modifications (intake, exhaust, ecu) will put it all the way to 390 or so horsepower by increasing the boost to about 12 psi from the stock 9 lbs. The new ecu is programmed to make the best use of the extra airflow through wastegate, timing, and fuel optimization, as well as some other changes, and the result is an impressive 310-320 hp at the rear wheels, and of course much more at the crankshaft, for about $1500-$2000 worth of mechanical modifications. The Z currently runs high 13's, and will do VERY low 13's after the changes are made. "

 

I am building a 389 LT4 right now. Email me if you want details... sounds like you want exactly what ive wanted. My LT4 will revv 7600 rpm and should make from 450-475 rwhp. Just be prepared to spend large $$ to make sure its done properly. Im still at the stage of making sure i go with the right computer system to be able to revv that high, and maybe even a coil/plug setup. THose 300 guys are lucky though, those motors put our stock motors to SHAME :yesnod: That 300 TWin Turbo block has forged crank, rods, pistons, a 4 or 6 bolt mains and a stud girdle... those are seriously built motors. Just remember those cars are also porky and overweight. Your friend will be blowing up those dinky clutches and dinky halfshafts before he ever gets to line up with you!! :lol:

anyhow email me if you want any details or have any questions. :cheers:

 

Yeah. i know that they arent that quick stock but its just everything put together that scares me. DOHC, 24 valves, high ratio rear end, Boost controller, and that fact this kid is the BEST driver. according to twinturbo.net he has the like 3rd or 4th quickest NA z in the country and i dont doubt it. that kid knows his car inside and out! i guess its practice time with my car for me huh?


On the other side of this arguement i would just like to be able to have him not blow me off the raod to embarassingly. when i do my rebuild i will beat anything he wants in te way of times. he only wants a mid to high 11 car in the end. i want a little bit more. i understand it takes lots and lots of $$$$. trust me i have been doing my homework but i want to build a pretty hot motor in this thing someday. very simalar to what was done with hoover. hoover is putting down 500rwhp and like 525ftlbs. not as much as i would have imagined and he is pulling mid tens. so i dont know i have a lot of homework yet to do before i tear down my motor to build up a hell of a racing beast. but thanks for all the great information! you guys are the best!

 

300ZX tt :yawn:

can we say tt ZR-1 engine? 32v DOHC? :chevy

or... uh oh. dare i say it. talk to your friends at porsche 928 they can build you some very trick variable cam timing twin turbo heads and a computer to run em to 7200rpm. i mean JUST KIDDING :jester

 

if he beats you introduce him to Limey :lol: :lol:

 

If you get a good head cam package with all the goodies you'll get around 400rwhp, then just get nitrous and put a 100 shot in it and you will be set for a long time till he figures that a 3 liter ain't touching a 5.7L.

 

Personally I’d start with induction, exhaust, and gears first. But since you asked here a few “off the self” high rpm hydraulic roller cams to consider.

Comp Cams 306: 230/244 dur. @ .050, .533/.576 (lift w/ 1.6 rockers) 112 lsa
Comp Cams extreme energy: 236/242 dur. @ .050, .555/.576 (lift w/ 1.6 rockers) 112 lsa
GTP 6 cam: 235/242 dur. @ .050, .568/.592 (lift w/ 1.6 rockers) 112 lsa

With any of these cams you’re gonna need “good” heads, a bulletproof valvetrain, and a good dyno tune. Also, I think the factory PCM is only good to 7,000 rpms. Get w/ Norris Motorsports (a forum vendor/tuner) they are in your area, and see what they think. E-mail me if you want a detailed list of my mods. Good Luck

 

The factory PCM only has tables to 7,200 RPM, you cannot rev any higher than that unless you use aftermarket engine management.

I have a CC306 and it makes great power. My HP peak is at 6,600 RPM, but I'm only down 5 RWHP when the PCM shuts off at 7,200.

I'm very happy with this cam, it sounds killer and backs it up :thumbs:

 

Remember this. A lot of people here are going and have gone OVERKILL with cam specs. Ive seen huge durations and no revving capability. Think of this one... i asked someone what kind of duration i would need for 7500 rpms. he told me say 250-260 give or take. then i asked him how the zo6 cam with 206/218 pulls hard to 6500.. he was speechless. Basically what i am saying is get to know a reputable shoppe who KNOWS what they are doing. That is the most important first step. Tuning is anothe rimportant aspect. Tuning will decide how your car will idle. If you deal with a knowledgeable shoppe they will know what they are doing with the tuning and can help make sure your car stays perfectly driveable and makes the most of the setup.

For high rpm, there are basically 3 things you need.. Killer components, an aftermarket computer system, and a mechanical roller setup.


His and your problem will be traction most likely. His 300zx is fat and has the wimpiest rear end and halfshafts. I guarantee he will break more than you can count if he keeps upping the boost. There are limitations to everything. I dont plan on racing on the street so i could care less about wheel spin with my 19s on. WHat i care about is sending people home with their tails between their legs after im through with them on the highways. :lol:

Basically, anyone can tell you that it takes lots of planning and lots of research. If you do a buildup you have to try and figure out exactly what you want before you go headfirst or youll find yourself changing parts and wasting lots of $$. trust me on that one. ;)


[Modified by DieL, 3:55 AM 8/29/2003]

 

The hot cam should continue to pull very hard past 5000 rpm's. It's just getting warmed up about then.

In any case to increase your redline you've really got to look at your bottom end and your valvetrain. I'll go so far as to argue that the valvetrain is more of weak link in the LT1/LT4 than in the bottom end. The LT1/LT4's have 4 bolt mains and will take a good deal of punishment. Some people say they won't last a second past 6000, others push them harder than I do. My rev limiter is set to 6500 rpm's. I don't push it that hard every day but I have rev'd that high a LOT without any trouble.

The valvetrain will need very good springs to make sure that they can handle the pressures. I'm running an absolutely huge spring that would easily take 7000 rpm's but I don't trust the bottom end that far :)

Also rumor has it that you can seriously strengthen your bottom end by upgrading to ARP rod bolts, should gain a couple of hundred RPM's for a fairly small amount of money.

As for your friend I wouldn't be worried about it. The reason he has such a tall gear ratio is to make up for the lack of torque. That also makes his redline run out faster. It sounds like you're about to get in a money war :)