my56oval

Hello everybody. I have a N/A 88 gxl and the engine is losing power so i just want to put a new engine in.
I was thinking about a TII but people keep talking trash about them and say that N/A is better. I can get a t2 engine with tranny for $750 with 30k miles on it. or should i just rebuild my n/a. what do you guys think the better choice is? and how hard is the convertion for a t2

dr0x

Id put money on the fact it has more than 30k miles. Jspecs are ripped from junkyard cars in japan. And a tii conversion is not worth it. Sell the car and buy a tii or just do a big port NA.

crazyassrx7

If you can have proof that the engine really has that many miles and has good compression go for it, but it wont be cheap, you will prolly need the differential an other things and not to mention a lot of time for the t2 swap

If you dont feel like going through this i would go with drOx and make a big port NA and maybe even use some NOSSSS

Jimmy325i

I can reproduce my engine for 1500, so that'll give you stock t2 power with no additional costs and you'll have a fresh engine out of the deal.

That's 163rwhp on a really bad tune...

Drifter101

Might aswell go find a NA engine somewhere rebuild and port it. There is entirely alot of work involved in doing a Tii swap and not to mention alot of parts

Jimmy325i

I'm talking all motor n/a here. (incase you didn't catch that from my profile)

Using S5 rotating assemblies would also bump up that hp number a little as well.

"turbo... We don't need no stinking turbo!"

Barwick

Wow, that's funny.. for less than $1500 I got a J-Spec TurboII and modified it putting 193 at the rear wheels on a mustang dyno (not dynojet crap) running 13.7 @ 104 on five pounds boost. AND it's never given me any problems, starts right up every time, never floods, runs strong as crap, and shows no signs of letting up.

Go Turbo, and just take care of it like you're supposed to take care of a car, change the oil, fluids, don't romp on it cold, don't overboost it without proper fuel setup, etc.. like I said I'm 193rwhp 13.7 @ 104mph with only 5 lbs boost on my '90 TurboII. The car (purchase) and engine and everything I added optional (new brakes, tires, exhaust, intake, wheel bearings) ended up costing me $3500 by the time it was all said and done, car, engine, extras. Not too bad.

Barwick

And how the heck did you get your car down to 2400 lbs (did you actually weigh it on a good scale?)

I'm 2880 with a full tank of gas (18 gallons), full topped off fluids, some stuff in the back hatch area, 40 lbs of books and tapes, etc..

I'm all up for weight reduction.

jon88se

The TII swap is not really that bad if you have the right people working on it. Experienced rotary-people who have taken out and re-installed TII motors should be able to cover the swap in a weekend. You will need a bunch of parts so trying to find a complete TII motor is really the key. Past that you'd need the AFM, boost sensor, knock box, ECU and harness. Call local junkyards, search the net for mazda-junkers. A TII motor will mate just fine to an NA drivetrain as long as you use motors/trannies of the same series (86-88, 89-91). This would be a big deal for your local tuner shop but an easy affair for any reputable rotary shop.

Jimmy325i

Yes, I weighed my car on a real scale. Should be under 2400 right now. I've since removed more interior crap and my air pump.

You have a used motor. I'm talking about a new motor which will get far better gas mileage, and last longer than your t2 swap. Seen any 200K turbo 13b's lately? ever? No turbo guy who knows **** about the engine will say it is a more reliable motor than the n/a.

I can also pull high 20's for mileage if I stay out of it.(around town. freeway I can get mid 30's) When was the last time you broke out of the teens?

SonicRaT

iTrader: (6)

The TII swap is pretty god damn easy. And btw, I've seen a lot of turbo's break the 'teens' in gas mileage putting down more than your N/A is, reliable? Well, that's a given, but you're gonna go faster in the turbo, and to most people, going faster is better than being reliable.

my56oval

The Place where im getting the engine was recommended from a friend but he got an N/A engine from there and he said it was fine. They also said they check the compression and i get a 30 day warrenty. The only thing im worried about is getting it tuned and getting all the parts im going to need for it.
How much does it cost to get my N/A rebuild? anyway i got about $3k to spend on my car so hopefully it will cover everything. I know its not the same but my brother and i rebuilt my engine on my 68 camaro and installed it ourself so i dont think its that hard to put in a t2 or an n/a ourselfs right?

Jimmy325i

Like I said earlier, I will build you a clone of mine for 1500. (excluding any hard parts which cannot be reused)

This would be a 4 hour plug-n-play job for you once you got the motor back. (I can turn one around in a week if I know its coming so I can get the kits and such)

The turbo conversion is significantly more involved. New fuel pump, ecu, wiring harness, entire drivetrain swap (or auto driveshaft to adapt the turbo tranny to the rear end)

Any competent mechanic who's good with following and working with EFI electrical systems should have no problems with either removal and reinstallation. You'll want to search for the "bare block" modification threads in either case. Lots of engine clutter can be eliminated while you have the motor out.

Check out my "Dyno Dismay" thread to view my motor's output running alcoholic rich. (runs much better when its not nearly being flooded) But the lean spike indicates how much torque she's capable of.

Kevin Landers is another excellent source of rebuilt engines. I'm sure he could hook you up with a healthy port job as well for a similar price. I'm not sure what his lead time is though.

In the end the turbo will cost you more. Maybe not initially, but even the fanatics will agree with me on this one. They also are more picky about routine mantenance. (something you have no idea about up until this point in that used motors life)

I personally built my engine with the intention of runing massive shots of nitrous in the future. (like 200hp shots) 600 bucks wont get you a good turbo upgrade. I can have all the power the block will handle (same limits on both turbo and n/a motors) for another 600 bucks in go-juice.


I'm not really trying to sell you on my zen motor (my nickname for it) because I want you to do what you want to do. Build your car the way you want it. Turbo's are fun, but turbo rotaries are not reliable. I'll build you a damn good motor if you want me to. If you want the turbo conversion... have at it. We're all here to help either way you choose.

Barwick

You're kidding me.. you drive a sports car and you're whining about gas mileage?

For a N/A to put out the power that my motor is putting out (not much), it would be NOWHERE near as reliable as my motor is.

Jimmy325i

Well, I drive a low displacement sports car and I do care about mileage. Many other people do to. If I didn't care about mileage I would be driving my 300hp 450lb/ft tq suburban which would smoke your no torque making t2 if it didn't weigh twice as much. That truck gets 12mpg. (which really isn't too bad for the #'s it puts down)

If I wanted a gass guzzler I'd trade my car for a mid to late 90's trans am and be faster than you in 200 dollars worth of mods and have a 200K mile n/a motor at the same time.

But, I like cheap fast and fun cars so I keep the 7. I'd rather spend the money you waste on gas for things like better tires and girls.

You say you're a business owner in your profile. Do you buy from the more expensive guy just to satisfy your ego that you can "afford it?" Why make a car get 15mpg when you can have the same performance and it still can get 20?

And last but not least... From your very own sig. "193 rwhp on Mustang dyno (~241 flywheel?)" Ok so you might have 10 more wheel horsepower than me (big maybe, considering I dyno'd at 3 points rich with retarded timing) and you say you make WAY more power than me? Are you really that ******* dense?

Jimmy325i

Oopse, your sig says you did a 13.7... The trans am would beat you stock. My bad.

Barwick

And I could go out and get a skyline and... what's your point? We're talking N/A RX-7 vs Turbo RX-7 here. I wouldn't mind having an N/A peripheral port, but it wouldn't be a very good daily driver.

I'd rather be filthy rich and be able to afford it

You're kidding me, right? Your car is just about maxed out. Mine's hit a plateau, if I want to go cheap I can get injectors, fuel pump, and an SAFC and run 10 lbs. It won't be in the 13's anymore, but I prefer to make sure my engine is safe, and am going standalone.

10 more wheel horsepower? Go ask someone what a mustang dyno runs compared to a dynojet dyno. I don't know the exact numbers, but I'd guess I'd be putting down 220 on a dynojet. Not too special, but if you consider I'm only running FIVE pounds (aka less than stock) boost..

For how much money? Mine cost me $1500 to buy, and $2000 to replace the engine and get new tires, rotors, pads, rear wheel bearings, exhaust, and intake. $3500 and it's not going to need major work for another couple tens-of-thousands of miles. AND it outhandles that boat of a car they call a Trans Am.

Once again, N/A RX-7 here vs Turbo RX-7.. if you want to get into it, I could go get a top fuel dragster and.. you get the point. Keep on topic here.

Barwick

Oh and by the way.. high peak horsepower is much different than medium peak horsepower with a wide powerband.. go drive a Celica GT-S and tell me that's a good engine (it sucks).

my56oval

Thanx for your help guys so i think im just going to try to rebuild the enigine myself and see how that goes and if i fail then ill just go buy a t2 engine and slap that thing on

ilike2eatricers

Sorry if this sounds stupid but what are the s5 rotating assemblies you are refering to and how much hp would be gained? Thanks

Jimmy325i

My engine runs the lower 9.4:1 compression s4 rotors. S5's run 9.7:1 compression which is probably good for about 10-20 hp across the board, (not just peak hp) and likely a decent increase in torque as well.

ilike2eatricers

thanks for the clarification

TonyTurboII

Hah. Tell me where your putting that $200. Cause anything for those cars is ungodly expensive. These cars are 3 to 4 times more than a TII.

Dont think so. My friend had a 25th anny TransAm. It was slower than ****. Easily dusted by stock DSMs. You'd be lucky if you could turn a 13.5 out of a new one. Even if you could, You'd be 25,000 in the hole.

Jimmy325i

you can get a 94-96 TA for about $5K around here and they start with 300crank hp and something like 275lb/ft.

Throw an open exhaust on the car and you're set. 200 bucks. Do some weight reduction (non-essential crap) free and you'd be well on your way.

DSM's are a reliablility nightmare. Not even worth the arguement here. I have a friend with several thousand in mods on his 2nd gen putting 360hp to the wheels and he can't keep differentials in the car long enough to pay them off. Also, the ecu to make that power is 1K itself. (dsm link)

TonyTurboII

275 crank hp actually.

And where are you finding exhaust for the car for $200? You'd be lucky to get just a muffler for that. Not to mention exhaust isnt very benifical for the f-body.