decision time! greddy t-78 kit or gotham gr63?
 

i've read good things on both these kit.... they both make good power.. the gr63 is said to spool very quick.... but the t-78 i'm led to belive makes high hp....

right now i have a apexi power fc, apexi gt spec exhaust, rx7 store mp and dp, apexi intake, and koyo rad....


what are the cons to either of these kits? my goal is to have a healthy strong running car. i'm not worried about drivability to much as this is my weekend car... thanks!

Since your running a power fc, Im assuming your building a street car so in that case, any of the "main stream" turbo's out there, ie...T78, GR63, PFS-PT67, TO4R......you get the point. They all will make anywhere from 400-450rwhp on 15psi. Your not going to run much more than 15psi on the power fc anyhow. 20psi on race gas maybe. Anyhow, all of these turbo's made good power. As for "high" hp, that depends on your definition of high hp.
My definition is over 600rwhp and you'll never see that any "street turbo".

Why would you not run more then 20psi on the power fc? Jason at Rx7store.net has a good deal on the T-78 kit right now.

Buy it, its an awesome street turbo. As for running more boost than 20psi the resoulution gets to fine to be able to tune realiably. Thats why you don't see anyone doing it. Also, the ignition then becomes an issue.

Do you mean the resolution the power fc tunes in is not fine enough to reliably tune 25psi? What computer do you need to run this high of boost? What boost level is an hks twin power good up until? What ignition upgrades do you need past this boost level? Thanks ahead of time but I planned on running this boost level but was not aware that i needed to change my power fc for something diferent. Sorry for hijacking this thread but ill stop after this.

yeah, 15 pound is penty right now.... that plus a streetport and other things will make plenty of power for me...

after you get above 20psi the PowerFC gets spread pretty thin in the cells...better go to a MicroTech or Haltech. the HKS Twin Power is fine for "stockish" boost levels...but if you can afford to go single then you can afford a decent ignition...actually if you are a smart buyer and somewhat mechanically inclined, MSD boxes and coils can be had for the same if not less than a Twin Power.

as for the original question...i'd go with a GR63 because EVERYONE has a T78.

What are your horsepower goals?

The HKS twin power as stated is ok for 15-20psi. Anything over your going to need alot more spark. Computer wise, you'll need something like a Microtech, Motec, or Tec 3.

Question, Why is it you THINK you can't go about 20 lbs safely. Yes the resolution does get too thin, however do you guys know what ADJUSTABLE breakpoints(load and rpm) are? That is exactly what they are there for. Spread em out thin during vacuum and low boost(<8lbs), and then now that you have an "extra" 4-5 breakpoints Move then up top. NOw you should have all the resoultion you need.

Ty

Last time I checked the PFC resolution had more cells than a standard Mircotech (20X20 vs. 16X16) so I don't see why it would be any worse. Plenty of people have run high boost on much less. You would need to use the Datalogit software to change the cells around, but any experienced tuner shouldn't have any problem with that.

I hope that 20 psi is not a problem for the PFC. I got everything setup for 20 and I would hate to see that the PFC can't tune for it....now.
I believe there are several guys using the PFC to @the 20 mark.
I like the ability to no split and negative split with the PFC.....

i would say go for the t78. Its a great high HP turbo for medium to high rpm spool. The reason why most choose it is because its a very popular turbo that you can get here for dirt cheap if you look around the for sale section. as for the gtr67 gotham racing got 430hp @ 17psi. while a friend of mine ED has gotten 461hp @17 psi. but the gtr67 will spool about 1000rpm quicker. choose either quicker spool or higher horsepower

this is the gtr67 dyno. so if someone can show a t78 dyno to compare

http://www.gothamracing.com/pics/Ste...%20kit%202.jpg

Question, Why is it you THINK you know more than I? lol...I've forgot more than you'll know, young grasshopper.

Anyhow, those 4-5 points are doing shit, when your running more than 20psi. You need alot more like you have in a Haltech, motec, Tec 3, or Microtec. Again, why is it that everyone thats made big power (over 500rwhp) was with something other than the pwr fc??? Case closed.

First off, I apologize if I came on too stong, I didn't mean to insult you!. I personally feel the haltech is worse than the PFC, that is just my opinion, I have no expeirince with it though. Motec, you got the win, Motec is good stuff. Microtech, I guess it would depend on which model you got wouldn't it. Honest question here, how much resolution does the LT8s have? Ohh, and to reopen the case, Jason at the Rx7store, with his project car, 506 to the wheels, tuned with a pfc. Several local guys around here are puching near if not over 500, all on PFC's. Again, I didn't mean to insult you, I apologize.

Ty

Check out LUPE's thread here in the single turbo section he put down 533 rwhp with a PFC and a little help from Steve Kan. This was at 23 psi, so the PFC is perfectly fine at that level.

As for the turbos, my personal opinion is stay away from most if not all GReddy products especially their turbos. Original parts are hard if not impossible to source, cost and arm and a leg and just aren't worth the trouble. I assume the turbo from the Gotham kit is pretty close to an off the shelf Garrett unit that you could purchase almost anywhere or have upgraded or repaired without much trouble. You would also be supporting a rotary based small business instead of a shitty, poorly run, huge, monopolistic company like GReddy.

I would definetely go with the Gotham Racing kit. It, being a standard TO4 off the shelf turbo, will offer the best path of upgradability.

So unless you get a SMOKING deal on the T78 kit, go with the standard, go with the GR kit.

i have the gotham kit now!!! my car is in a million pieces and i'm trying to figure it all out.... this thing is huge next to my stock twins....i went with aftermarket fuel rail and 1600cc secondary inj. as well as upgraded fuel pump...

wish me luck, as i'm very confused.. but this site is answering a lot of questions, just hours of reading and searching.. thanks

Go with Gotham.

Gotham Kit, it's a performer.

Ernie, why not adjust the cells so that you can have more cells for the high end boost. I know Guys who run 30 PSI on the PFC. I use race gas and will run up to 26 PSI with a knock reading of ten in those cells when I datalog. I am running 10.5 afr`s at that boost and timing is pulled back.

Im not saying you can't do that, but its becomes such a broad range, there's not much room for actual tuning and mistakes can be made that way. Also, with a quality stand alone, you can make alot more power because of so much more tuning points. Also when you run over 25psi, you'll really need to address the ignition system and a DLI won't cut it.

:rolleyes: I will post my dyno sheet when I get a clutch and steve kan tune this may. I promise you it will be well over 500rwhp.........

Promises, promises.....:) LOL...........

Wanna make a friendly wager?? Since we both have the "same" turbo kit (ie..GT42R), Im gonna say I'll make atleast 75rwhp more than you will, when Ray Wilson gets done tuning me. (Im running a Tec3) .....what do ya say??:)

Oh, and mine won't be done in May, it'll be done in about 2 weeks....