All to many times i have heard people say that you can't turbo a non turbo motor, i have also heard people say that you can do it but with small amounts of boost, maybe 5 psi tops. Well there are alot of misinformed people giving advice, i was told it shouldnt be done, but did it anyways and it worked great, plus i ran 12 psi of boost, with an intercooler of course! im about to do the same thing to a 79 280zx. it has the stock engine. i will put a zxt fuel pump, airflow meter, injectors, fuel pressure regulator and of course an intercooler, all this with the stock 79 280zx harness and ecu..what do you guys think about that? im not trying to sound like i know it all because i dont, and i know maybe a turbo motor is stronger and might last longer but i know from my experience that it does work and 5-7 psi is definetly not the limit!
lets get this na/ turbo debate settled!
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You can turbo anything. it just depends on how much the engine can handle boost without detonation. N/A l28 is no different then L28t. L28T just have dishtop to drop the compression and the cam. With good engine management, cool intake air, and enough fuel, you can boost higher than 6 psi.
I don't think the stance was so much "it can't be done" as it was "what's the point?" when you can simply drop in the completed package by using an already turbo'ed L28 motor from a donor car. Seems to me that route is cheaper, easier and less time consuming than the way you did it. But hey, I've been wrong before.
The only problems I see with this modification are these:
1) the stock pistons in the L28 are not designed to handle the compression ratio developed by a high compression application and be reasonably sure they will not break.
2) the N/A piston top ring land is not machined into the piston to ensure the ring will not break, or burnup, or get carbon clogged.
3) the cylinder head gasket was not designed to maintain a seal over extended run time at high compression ratios.
4) the detonation factor has much lower tolerance to detonation in regard to not breaking parts.
5) the standard bearings, although they are better then Michigan bearings, are more susceptable to failure earlier then the cleveite 77 bearings.
This is just to name a few, and that is not taking into consideration of the cam timing and overlap in regards to reversion.
Can you do it? I guess it is obvious you can. I am running static 8.5:1 compression on my turbo application, and some guys have gone to 9:1 static compression.
I am still ahead of the game with my engine in the short run and tha long run. I have built the bottom end to do the high compression and not break within reason, The head will stay sealed unless it melts down. The gasket is bullet proof and will maintain a seal over the long run.
the cam is ground with the turbo application in mind and I gain more hp because of my grind.
I fully expect the engine to last 150-200K miles
and finally, I am running 20psi of boost, with the limitation on the injectors in stead of the engine. So my engine cost more to build, but I can modify or increse Hp without worrying about it blowing up and I will be able to produce more Hp then a stock engine configured with a turbo because it will stay together at the higher boost levels.
But on the other hand, if you dont mind changing engines when they break, a stock bottom end in the junk yard is relatively cheap and you can blow a few of them for what it cost me to build mine for race.
1) the stock pistons in the L28 are not designed to handle the compression ratio developed by a high compression application and be reasonably sure they will not break.
2) the N/A piston top ring land is not machined into the piston to ensure the ring will not break, or burnup, or get carbon clogged.
3) the cylinder head gasket was not designed to maintain a seal over extended run time at high compression ratios.
4) the detonation factor has much lower tolerance to detonation in regard to not breaking parts.
5) the standard bearings, although they are better then Michigan bearings, are more susceptable to failure earlier then the cleveite 77 bearings.
This is just to name a few, and that is not taking into consideration of the cam timing and overlap in regards to reversion.
Can you do it? I guess it is obvious you can. I am running static 8.5:1 compression on my turbo application, and some guys have gone to 9:1 static compression.
I am still ahead of the game with my engine in the short run and tha long run. I have built the bottom end to do the high compression and not break within reason, The head will stay sealed unless it melts down. The gasket is bullet proof and will maintain a seal over the long run.
the cam is ground with the turbo application in mind and I gain more hp because of my grind.
I fully expect the engine to last 150-200K miles
and finally, I am running 20psi of boost, with the limitation on the injectors in stead of the engine. So my engine cost more to build, but I can modify or increse Hp without worrying about it blowing up and I will be able to produce more Hp then a stock engine configured with a turbo because it will stay together at the higher boost levels.
But on the other hand, if you dont mind changing engines when they break, a stock bottom end in the junk yard is relatively cheap and you can blow a few of them for what it cost me to build mine for race.
I figure that if i goto the junk yard yank out an afm, fuelpump, injectors,fuel press reg and other small parts that i would need it would cost me less than $100 bucks...thats pretty cheap...and if an engine was in good to excellent condition i figure it would last for a good while!..just my opinion...i know there are better ways to go..more money more power and more reliable...see ya jim
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Amen Jeff!
That's the easy route: boost the hel out of the stock engine until it breaks, and get another from the junkyard after it breaks.
Using CHEAP stockers is MUCH more efficient than thrashing forged-piston motors!
Thrash the stockers until you get the nuances of the fuel management system you are orking with and THEN buy the forged slugs!
On an aside, working in Mexico for the next two weeks, so I TOTALLY expect to cross the border with some ILLEGAL paint! Laquer, of all things! Paint Sharkie in the driveway agin!
Don't drink and post!
That's the easy route: boost the hel out of the stock engine until it breaks, and get another from the junkyard after it breaks.
Using CHEAP stockers is MUCH more efficient than thrashing forged-piston motors!
Thrash the stockers until you get the nuances of the fuel management system you are orking with and THEN buy the forged slugs!
On an aside, working in Mexico for the next two weeks, so I TOTALLY expect to cross the border with some ILLEGAL paint! Laquer, of all things! Paint Sharkie in the driveway agin!
Don't drink and post!
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433 Posts
I agree with JR just get the whole set up and drop it in and save your self time and money. and why bother yes it can be done with unlimited amounts of money you could probley make a dirt bike faster then %$#@. But it's all about how much you have to spend, what your willing to spend, and how fast do you want to go.
tbs
tbs
if i had tons of cash...
i would have a 3.1 stroker with a t3/4 hybrid turbo, sds system and all the goodies i could throw at the car, but i have a family, a crap job that i hate and alot of bills, and an obsesion with turboed z cars..so this way is reasonable for me..and affordable and it works for now..see ya jim
i would have a 3.1 stroker with a t3/4 hybrid turbo, sds system and all the goodies i could throw at the car, but i have a family, a crap job that i hate and alot of bills, and an obsesion with turboed z cars..so this way is reasonable for me..and affordable and it works for now..see ya jim
I'm doing a combination of the two
If I cant cheaply fix that slapping sound in my '77, I'm droping in my 83zxt engine, using the '77 FI w/ turbo AFM, turbo injectors, turbo fuel pump, and what eve else I can use from the turbo engine. the best part is I plan on spending a grand total of $0 on this swap, unless I splurge for a boost gague and controler.
Justin T
If I cant cheaply fix that slapping sound in my '77, I'm droping in my 83zxt engine, using the '77 FI w/ turbo AFM, turbo injectors, turbo fuel pump, and what eve else I can use from the turbo engine. the best part is I plan on spending a grand total of $0 on this swap, unless I splurge for a boost gague and controler.
Justin T
I did it
I have the original 70K mile 78 n/a block with a P90A head on top and have run up to 17 psi with an SDS system and Spearco IC with no problems except severe tire wear and a smoked clutch. I usually run between 10-12psi most of the time and have near 10,000 hard miles on this setup. The 78 pistons have the same dish volume as the turbo slugs so CR is the same. Turbo pistons are cast and are not significantly stronger than n/a and although the ring package is different it shouldn't make much difference in longevity untill I put many more miles on it. If you detonate it's academic anyhow since that will break even the finest of forgings and fry the most expensive moly or gapless rings you can buy,the good stuff might last 6 seconds instead of 3. The Nissan turbo head gasket is the same part # as the n/a for 82-83 motors. Crank,rods & rod and main bearing material & construction are the same between factory n/a and turbo motors. I did use turbo head bolts,82-83 Nissan head gasket,83 turbo automatic oil pump,420cc injectors & a good fuel pump so I didn't totally cheap out. The motor has never detonated or run lean. Will my engine blow tommorow? Maybe,maybe not. But if it does I don't think an F54 block would have lasted much if any longer. So to make a long story short,yea it'll work.
I have the original 70K mile 78 n/a block with a P90A head on top and have run up to 17 psi with an SDS system and Spearco IC with no problems except severe tire wear and a smoked clutch. I usually run between 10-12psi most of the time and have near 10,000 hard miles on this setup. The 78 pistons have the same dish volume as the turbo slugs so CR is the same. Turbo pistons are cast and are not significantly stronger than n/a and although the ring package is different it shouldn't make much difference in longevity untill I put many more miles on it. If you detonate it's academic anyhow since that will break even the finest of forgings and fry the most expensive moly or gapless rings you can buy,the good stuff might last 6 seconds instead of 3. The Nissan turbo head gasket is the same part # as the n/a for 82-83 motors. Crank,rods & rod and main bearing material & construction are the same between factory n/a and turbo motors. I did use turbo head bolts,82-83 Nissan head gasket,83 turbo automatic oil pump,420cc injectors & a good fuel pump so I didn't totally cheap out. The motor has never detonated or run lean. Will my engine blow tommorow? Maybe,maybe not. But if it does I don't think an F54 block would have lasted much if any longer. So to make a long story short,yea it'll work.
I also considered going with a stock bottom end and just going for it, but the thought of yanking an engine just did not appeal to me. Besides I wanted to do some custom engineering in the bottom end to increase the torque and I really wanted to stroke the bottom end also, again for more torque.
I bit the bullet and just built a bottom end that I wanted and it is just about bullet proof at this point, and it has proven to be a torque monster.
Now all I have to do is get some of these manufacturers to deliver their parts without taking 6 months to get, it gets so irritating listening to all the bull excuses.
I bit the bullet and just built a bottom end that I wanted and it is just about bullet proof at this point, and it has proven to be a torque monster.
Now all I have to do is get some of these manufacturers to deliver their parts without taking 6 months to get, it gets so irritating listening to all the bull excuses.
Jeff,I know from reading your posts your a high rpm guy so in your case the forged pistons & tri metal bearings are a must. Since internal engine stresses go up with the square of rpm its alot harder on an engine to go from 6000 to 7000rpm than going from 5K to 6K. I rarely if ever go over 6000 so maybe thats why my junk is still in one piece,knock on wood!
Interestng thread but, as you can see, there really isn't a debate. The question that is usually posted is some version of "what's the best way to turbo my car". While a competent mechanic can make almost anything work, without knowing anything about the poster and his/her abilities and understanding of basic mechanics, it seems the best advice is to point the poster in the direction of "bolt on, plug in" factory parts/systems.
Can ya turbo an na car? Sure! But I don't see anyone arguing about which is the BETTER way to go. The turbo'd na setup may initially be cheaper but considering that most peoples time is worth something and not everyone's mechanical ability is even, the "factory" setup remains the best answer to "what's best".
Dan '81ZXT Portland, Oregon
Can ya turbo an na car? Sure! But I don't see anyone arguing about which is the BETTER way to go. The turbo'd na setup may initially be cheaper but considering that most peoples time is worth something and not everyone's mechanical ability is even, the "factory" setup remains the best answer to "what's best".
Dan '81ZXT Portland, Oregon
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