Going to the dyno today, any guesses?
 

I am going to Stage 6 here in town today to get my car dyno'ed.

I am hoping for high 200's at the wheels, but we shall see.

I will post pics of the dyno and the slip tomorrow.

Stock ports? What kind of exhaust? How much boost?

I guess 101hp.

Im with ya on at least 200. Its a Cartech turbo kit right? Arent those rated at almost 300?

~T.J.

A T76 on possibly a 12A??!??!? Good Lord!

i'd bet you're over 300....I have a Cartech kit on my 13B and Corky Bell himself rated my setup at over 350HP.

I would say not more than 200 rwhp, its measurement that matters not rating. What is in the Cartech kit?

just for fun i'll guess...i say 284 hp and 208 torque

Did you forget to go to the dyno?

where's the numbers?

Okay boys and girls, can you say "My car is slow"?

186@7000rpms 8lbs.

Don't laugh too hard, you might burst a vein.

I was very surprised and very embarassed.

I was lean (13) at low rpms and okay (11) at high rpms.

I am thinking about turning up the boost to about 12-14lbs, rejetting the carb, changing the plugs and trying it again next week.

I was in such shock, I left without paying. I will be going back today to make payment for making an ass of myself.

What type of porting job do you have?

-Error

186 hp is nothing to sneeze at in a 2500 pound car. You car is probably quite fast indeed.

None.

Coming from someone who admittedly knows relatively little about turbocharging, your dyno #'s aren't far off from what I expected. On a stock port I'm not surprised with those #'s at all. That said, 186rwhp is probably ~twice what your car had pre-turbo at the wheels. I don't think you did bad at all, certainly nothing to be embarassed over. Cheer up :)

Thanks for the post man, I was just hoping for better numbers.

If anything, I am determined to get into the high 200's and I am going to work on it starting today.

I know the turbo has tremendous potential, but I just installed the air/ fuel meter the night before and really have not tuned the carb perfectly.

The guy down there (Tracy), gave me some advice on jetting, so I will follow that and crank the boost, probably to 14 lbs.

Does anyone know what the max boost on a T76 is?

i wish my car made 186 to the wheels. That's pretty damn good for stock porting and a blow-through system. (Not that i really know much about the stuff) but after tunning properly i wouldnt be suprised if you hit the 200 mark. Not bad for a "bolt-on" job.

If you get that thing street ported and tuned right those HP figures will be close to double your previous amount...believe me I know. Good luck man, don't be so hard on yourself.

I just installed an MBC, how does this thing work?

Is all the way in full boost or all the way out?

I think putting more stress on your motor by turning up the boost will hurt in more in the long run with those stock exhaust ports. I don't want to see another first gen on the side of the road. If you want to see a great increase in power with your current setup...get it ported. Even a mild street port will be better then forcing those small exhaust ports to do more work.

-Error

The guy I bought the car from said that the motor is ported, and it lops on startup, but I looked at the intake ports and they looked stock.

I am guessing that this guy would have at least the exhaust ports ported running a turbo.

Phew *wipes sweat off of forehead* I feel much better. :)

I really don't worry much about the intake ports as much as I do the exhaust ports.

I'm wondering are you getting an turbo lag and how is your clutch doing? (I didn't read through all the replies so I apologize for coming into this discussion a little late.)

-Error

There is some lag, but this is my first turbo car, so I have nothing to compare it to.

Dual friction clutch is holding up well, it was basically new when I bought the car.

Traction is a problem though, keep spinning the tires.

Shit, I would be happy if I could hit that number with my Weber blow through Im planning at 8 PSI.

~T.J.

186rwhp at 8lbs boost is reasonable with a stockport. Pushing up the boost further without dowelling may not be a good idea. You will also be getting to the stage where driveshaft, diff and clutch modifications should be considered. Without a good intercooler I suggest 9-10 ib should be your max boost with another 2 with a frontmounted IC. In an early response I suggested 200 hp max for your set-up, with a little fine tuning this should be possible.

OK porting will give you more power, but a strip down and port job is an expensive option at this stage

Good call BTW Paul.

~T.J.

I'm sorry but with a T76 one would expect more HP. A good start though. I'm N/A and got 220 ;)

winnepeg youve got a bp dont you? thats to be expected haha

dowelled? from what ive read dowelling is just a band aid for poor tuning. im no expert, im just regurgitating what ive read as i understand it. was a post on the aussy forum if you feel like searchin for it

gamble

Gamble. Dowelling is a well engineered modification to hold the engine components together when you are generating substantial power. Once you are above about 300 hp then its essential even when the engine is well tuned.

Extreme bad tuning, wrong air/fuel ratios, will generally cause major damage to internal components such as apex seals even if you are generating low power. Dowelling will not help you. One bang and you can be dead!

Winnipeg- each turbo has a maximum potential but whether this is acheived depends on other components. More boost will obviously give you more power. It also gives you more heat

Is the intercooler big enough to cope?
Will the plumbing stand the pressure?
Is the carb big enough to provide the fuel, with efi are the injectors large enough, what has happened to the Air/Fuel ratio?
Will the internals stand the increased pressure? Will the seals hold up? Will the engine fall apart in a dramatic fashion?
Will the clutch, driveshaft, and diff stand the extra?
stress?

Its like a pyramid of cheerleaders, one weakness no matter how attractive, and they all come tumbling down!

I think Winnipeg85GSL has a 302 in his car guys ;).

~T.J.

I was kinda kidding, I'd rather not start another arguement. I'm actually quite impessed with those numbers for a 12A.

he doesnt have a GAMBLE 302 in his though :P

yes ive read the dowelling is a great mod, but also that it isnt needed if you are properly tuned. do you have any links to more info on dowelling i could read up on? i really would like to know more about it

gamble

I've heard dowelling is unnecessary...

It would be interesting to know who says dowelling is not necessary. Top builders in Aus such as Dalton, Dyson ond Rotorworx all recommend dowelling for high performance motors.

Even top street machines use dowelling, but then we are talking over 500 rwhp@26 boost for 10 second 1/4 mile times. Once you get to 8 second RX-7s with a full race engine, dowelling is essential if you want to last the full 1/4 mile!

As a matter of interest the street set up I am considering is a "Stage 3" with four 12at injectors which will get me high 10 second runs on a 2600 lb RX-7[full street trim]. On a drive in-drive out basis it will cost about $12,500 with a rebuild. If I wanted a stronger driveshaft, diff and gearbox then the budget would be higher. Unfortunately the RX-7 parts are a bit fragile even for street use, and a Supra turbo box and HiLux diff are good options if the money allows.

If you are only playing with under 300 rwhp in a daily driver then dowelling is not so necessary.

Here Here

Well, I have a 13B, so base your numbers on that.

I am playing with a MBC right now, pretty scary how quickly the boost changes with just a little turn of the knob.

He made it a point to tell me that the back side housing was from a 91, he said the 87 engines had a problem with cracking?

Was he smoking crack? Or selling me some bullsh!t?

ok Paul you cleared that up.

Is there a difference between the 12a and 13b in terms of the dowelling issue?
I also heard that 12a need no dowelling up to a much higher HP figure than 13Bs

Well, my goal is to hit the 12's.

Robert at Rotaryshack.com is pushing 15psi. with no intercooler.

pillage6- running 15psi without an intercooler will really increase the charge air temperature. The usual professional advice is to use an intercooler from 6lb boost, 8lb max. A good IC can add in the order of 20% more power safely for the same boost.

The problem with just winding up the boost is excessive heat which increases the chance of premature detination, one of the major causes of engine damage [knocking/pinging]

To get power without damage you need a tight balance of boost, the air/fuel ratio, air charge temperature and ignition timing.

With due respect to Robert and the very high power numbers he posts on this forum , using 15psi without an intercooler seems a strange configuration to optimise the way of getting power. While its cheaper and reduces turbo lag, the chances of self detonation and leaning out due to reduced oxygen vastly increase.

To go back to the specific purpose of this thread, OK increasing your boost will increase power towards the 200hp or more mark. But my warning is that without an intercooler the chances of engine damage increases unless you manage to get ignition timing and the A/F mixture just right. An alternative is water injection but few people now use that approach since IC technology became so good.

You can relatively safely put your boost up for a dyno shoot-out with everything under control but on the road its a different situation. One problem is fuel quality/ octanf levels vary so much depending where you pick it up.

mperformance- like you I have heard the 12a engine has more strength reserve. To what extent there is no published data, one reason perhaps is that few people pushed up power on the 12a once the 13bt became available.

Looking up specs on the works race engines of the time is an eye opener. The 12a engine built by Racing Services of Twickenham for the UK Saloon Car Championship produced 190bhp. Even the 1981 Le Mans full race engine only produced 290bhp with a massive Mazda factory budget, The ouput of the IMSA cars of that period was only about 270 bhp in its NA format and 300bhp with efi. At that level of output dowelling is only a marginal option

Thus, 200 rwhp in a street car has to be put in historic prospective. Along comes turbo technology and you are in a different universe of options

Rice Racing uses no dowelling in his 500hp, 300km/h monster.

I was using the latest advice from Rotorworx who recommend 6 additional dowelling from 300-500rwhp and an additional 8 for above 500np. At a cost of $400-460 it sems woth while. when you have invested thousands in the engine

An example of dowelling by Rotorworx is Freeknu with 512rwhp@26psi, who achieved a 10.24 second run at the Adelaide nationals. Thats some going for a street car!

Its not that I am knocking Rice Racing, but I think a little safety is justified when the rebuild time is not free.