87hellbird

My 305 is getting worn down and i want to upgrade. I decided for my build i want a 283 with forged internals, use the tpi and hot cam from my 305 with 350 tpi heads with 2.02 and 1.6 valves with my 1.7 roller rockers. steel head gaskets and 2 turbos off two 2.5L subaru sti's, twin turbo intercooler, exhaust twin turbo headers, downpipe's, custom burned chip, small shot of dry nitrous that can cool the turbos for racing and high boost. What maf show i use or will my stock one work?

83 Crossfire TA

iTrader: (2)

283 with forged internals??? Why?

I'm usually the guy that likes oddball projects but I can't see how that makes sense unless someone else bought all the parts and you're getting them for free... Otherwise forged 350, 383 or even 396 parts will be cheaper, easier to find and make more power.

Orr89RocZ

iTrader: (20)

Am i missing something here? Your thread is quad t then twin turbo..i got excited and thought this was a quad turbo build...something I was thinking about doing just to be ridiculous and different.

This will be hard to control on the valve train...geometry gets pretty messed up and very picky on setup. I'd just stick to 1.5-1.6 rockers.

87hellbird

I chose a 283 cause the tpi would be really good on it, and i found someone with a bunch of them in my area and with that 350 heads i could lower the compression ratio easier on a 283 for more boost, and could possibly keep my tpi hot cam for a 283 but whats your opinion cause i could try and find a 350+ i just like the tpi. the quad t is kinda a joke a friend said cause its Tpi Twin Turbo Two83. but however if i could get a bigger motor like a 400 or big block i would not mind tryin a quad turbo.

b1k1w1

it would work and your right about tpi on smaller engine. But that's a lot of money for a small engine.

//<86TA>\\

iTrader: (14)

would TPI on a 283 be that much better than a 305? its only 22 cubic inches. thats nothing.

the mention of "someone with a bunch in my area" and "350 heads" leads me to believe the engine choice mainly because its there and cheap. Not an educated choice IMO. No offense intended.

b1k1w1

smaller cubes pull less cfm so need less cfm. So tpi would work. 22ci is a lot 355 to 383 28ci people spend a lot to get it. So lets say you make 1hp per ci 283,350,400. That's 117hp with only price difference is price of used engine. The only reason people do 350 over 400 is price. Some will say hard to find but you can find one if you really want it. Now that ebay and craigs list are here and 350s are going up in price there about the same. 400 2bolt is the strong one. Only down fall is tpi will not flow enough stock. With turbo and aftermarket tpi parts will help. Tpi 283 dished pistons stock crank rods light boost will be fun car and not brake the bank

Drac0nic

One day I'd love to build an oddball combo out of a 283 or an "off beat" SBC. Bit spendy but there are "some" parts out there. For a huge power build probably not worth it in a lotta ways though. If I were going to do it (keep in mind that's a big if) depending on my HP goals I would do it this way:

-L99 connecting rods, 307 pistons. Keeps the same stroke but longer rods. Either that or I'd have a "283 stroker" and get a small journal forged 327 crank and stick it in my 283 block for a 307.
-Some sort of aftermarket connecting rods. Small journal rods are supposedly weaker than medium journal stuff overall.
-305 heads. Yeah, you may be able to drop the CR easy with 64cc heads but why bother? You're going to probably hit a point you don't want to and affect drivability
-The cam choice is going to be important. You're dealing with a marignal intake not terrible but not great heads small CID and boost. That could be tricky.
-Port your TPI intake, that way you can get some more revs out of it.

As bad as this sounds, if you're going to build a 283 you may as well build a 302 by the time it's all said and done. Jam an L99 crank and rods into a 350 block with some 4" pistons. They may even make some off the shelf pistons do do it with 6" rods these days. Hell use an LT1 engine and you've got something that can breathe deeply with minimal work and will make some awesome power under boost. In some ways I'd really rather build the 305 with roller blocks being cheaply and readily available as well as likely having more/better piston choices out there.

87hellbird

Well I like the 283 cause it has a good short stroke so its easier for it to hit higher revs and with the 350 tpi heads and pretty big cam for a 283 it will hit high revs and i can put some major boost to it. yes a lt1 inj would be nice but i am doin this for a cheap build and i dont have to try and redo all the wiring. The turbos off the subaru sti's im lookin at can support up to 400 hp each, two of them can make plenty of power for me!

freaky

good luck an keep us updated ...

Drac0nic

The 302 would have the same stroke. What's cool about it is you could use stock 350 pistons with the L99 rods (recon a set and throw some ARP bolts in em) and they would be stronger than the 283 rods as well as supporting your 3" stroke. You'll probably pay 50 cents on the dollar for a set of shelf 350 pistons compared to the 283 ones, you'll have less bore shrouding etc.

Even with the smaller CID compared to the 305/350 TPI your combo will likely be mis matched with that intake. The option I would go with doing an LT1 style setup would be to convert the intake to use a dist then you could get away with using your TPI stuff still and get benefits of the LT1 setup like the head flow and reverse cooling.

That being said for some reason I have an infatuation with the idea of building 305s and boosting them (If I could get my stuff straight :/) and it's ultimately your money. There's also nothing impossible about swapping to the built 283 after you're done boosting this 305 either, which is something else I will throw out there for you to consider.

87hellbird

I would have to redo the chip tho for a 305 to a 283 after the 305 went out. the 302 would be great i just dont have the money i have a guy willing to sell me a 283 forged internals for 100 that is what started this whole thing. I also found a single turbo set up that would be great on this as well. I also have another question has anyone ever used nitrous to cool turbo boost?

-srs-

The best deals I ever got cost me more money than I can shake a stick at...

Drac0nic

Yes you would want/need to retune, but that's to be expected. Slagging a 305 is cheaper than slagging a built engine.

That's not a bad price for a core engine depending on what it needs. If it has forged pistons and is turn key/ready then it's a good deal. It gets real easy real fast to drop $ into an engine though. If it needs parts it may or may not be a good deal. Also be sure to verify the parts are what he says they are, everyone is selling an engine out of a Corvette or something. Even a 2bbl 305 came from a Corvette if you know what I mean.

Besides that, if you have a hot cam you're going to need to get link bar lifters to use it in the 283. Just keep that expense in mind. Those 350 heads must be pretty worked to use em with that kind of lift, if they aren't expect to add that cost as well.

87hellbird

Yes no matter what way I go it will cost money, I did some more research on valves and the 2.02 valves will hit the block on a 283. so i would probably stick with the stock valves on a 350tpi. And hot cam I mean by the cam in the 305s that made 215hp. I may only be able to use the 1.7s on the exhaust side which i am really ok with since this is a turbo boosted project I dont need the extra lift on the intake side.

lemons racer

Your right about 2.02s not fitting the 283 block but 1.94s feed it just fine, a buddy of mine ran a .060 over 283, with the old Manafree? 6-2brl. manifold with stock rods to 8000RPM and it never broke, except for valve springs, just flat wore the old girl out which really surprised me.

But like was said earlier, its not worth giving up cubes.Good luck.

InfernalVortex

iTrader: (4)

Going with a 283 instead of a 350 because it fits the TPI better is really thinking backwards. A larger displacement engine will still make the same power with a TPI, it will just do it at lower RPMs. Horsepower is THE SAME, but that's ONLY ASSUMING the 283 is hitting the flow limit of the TPI to begin with, which it VERY likely will not.

So with smaller displacement you get the advantage of higher RPMs, more expensive rotating parts,shorter engine life, and the same power.

Stroke has VERY little to do with RPMs. That has MUCH more to do with (in our context at least) camshaft, cylinder heads, and intake. If stroke is so important then how are there so many guys with drag cars with big cube big blocks (500+) cubic inches spinning 8,000 RPMs?

The only reason the 302 revved so quickly is because it was designed for racing in a series where they were limited to 5.0 liters. They did everything they could to maximize power with limited displacement - that means larger bore, huge cam, free flowing intake. The larger bore plays a large part in power, and that necessitated a shorter stroke to stay within regulations of Trans Am at the time.

It's true that shorter strokes allow for faster rotational speeds, but in the context of smallblock chevy's, it really is a small factor in the big picture.

The Ferrari Enzo with it's v12 that spins to 8,000 RPMs has a bore of 3.62 inches and a stroke of 2.96 inches. 3.62/2.96 = 1.22

The classic 350 has a bore of 4.00 inches, and a stroke of 3.48 inches. 4.0/3.48 = 1.15

Is that really that large of a difference? Do you really believe that .07 difference in bore to stroke ratio is the reason the Ferrari Enzo has a 8,000 RPM redline instead of a 4500 RPM redline of an L98?

More cubes is always better. If you can find a small displacement sbc for cheap, that's a great way to be build a turbo setup and learn how to tune it, so when you blow it up you're not destroying a $5,000 engine. You're blowing up a cheap junkyard engine instead. Just buy a cheap sbc and push it til it pops. When you get better with it, get a 350 or a 383 or a 400. Orr has a 400 twin turbo car... he's doing easy 9's. I dont think the fact that he isnt spinning it to 8,000 RPM is hurting him too much.

Horsepower is torque x rpm x conversion factor. The conversion factor is constant. That leaves torque (dictated by displacement) and RPMs (dictated by heads/cam/intake). You owe it to yourself to maximize every one of those. Restricting your displacement in order to improve the usable power band may work, but you will still end up with LESS power than you would have with even a 305.

Bore stroke ratios and RPM at peak hp:
Honda K20Z4 - 1.00 - 9500 RPM
Ford 4.6 Mustang GT - 1.00 - 4500 RPM
IROC L98 350 - 1.15 - 4400 RPM
Ferrari Enzo - 1.22 - 8,000 RPM
Not much correlation.

87hellbird

Yes the equation for horsepower is torque x rpm / 5454 the reason I am doing a 283 isn't just the rpm's but since I am forcing air through it, I dont really think it matters to much on cubic inch whatever i lack there i can make up for in cfm boost. Everything is to just make a cheap first turbo project to understand everything.

InfernalVortex

iTrader: (4)

More cubes is always more power. If you just want a cheap starter engine get a 305. I gave mine away for free because no one wanted it. And it ran great when I pulled it!

1985WS6TA

If you think the stock MAF can handle the power you'll be making, you're crazy! haha

Also the 112 LSA on the GM Hotcam is not really ideal for a turbo setup. You're going to want 114+ LSA for any boosted car.
Just sayin.

b1k1w1

the smaller cranks help you rev faster and if you lighten it even faster but it will get weaker so use forged then it will be good to 450 500hp. You can hit that with boost. 194 valves is max so get the valves cut to make up for it port heads you just need them to flow 250 cfm to support 500hp. Longer rods will get you more tq chose you cam based off of flow numbers. Fast rev 500 hp fun engine and it will last just as long. And rpms have to do with balance of rotating assembly

b1k1w1

the fast rev and high rpms will help the turbo

InfernalVortex

iTrader: (4)

Almost everything you have said is wrong.

1. Shorter stroke on a crank has a much smaller impact on rev speed than camshaft, valvetrain heads, and induction, ESPECIALLY in chevy's which are already over square. I already pointed out various examples in my original post.

2. forged cranks are heavier... so what's the point of lightening a cast one until you need a forged one? It still wont affect how quick it will rev because that's determined by cam, valve train, heads etc

3. Rod length is such an unimportant factor in engine power and performance. Longer rods are going to be better for prolonged high RPM's since there are lower inertial loads on the cylinder walls, but that is more for reliability reasons than performance reasons. Do they make a performance difference? Maybe a small one, but nothing huge. Ive seen more than one article debunking the long rod myth with dyno tests but unfortunately I can't find them. I did find this though:
http://www.enginebuildermag.com/Arti...y_choices.aspx

There's just no proof that longer rods make more power. I've NEVER seen any.

4. "RPMs have to do with the balance of the rotating assembly"? Kind of hard to know exactly what you meant since it's not a complete sentence, but I thought you already said it was determined by the "weight of the crankshaft"? High rpm reliability is affected by that, yes, but sustained high RPM operation is always going to cause wear on moving parts, moreso than lower RPMs. It's an inevitable by product of physics. You cant cheat physics forever.


Proof that bore/stroke ratio dont matter when it comes to high RPM capability:

Honda four banger - 9500 RPM redline. bore = 86mm stroke = 86mm
Chevy L98 - 4400 RPM redline - bore = 4.00 stroke = 3.48

The chevy has a much better bore/stroke ratio, but the 350's redline is less than half oteh Honda's. That's due partially to variable valve timing, but in our scenarious we'd just go with the bigger cam to begin with to get that longer exhaust duration taht vtec provides on the fly. And again that proves my point, the Honda goes to higher RPMs because of valve timing, not because of bore and stroke. Exactly the same as a chevy 302. It spins up fast becuase it has great heads, a good induction system, and a HUGE cam. Read more here:

https://www.thirdgen.org/forums/tech...dz302-sbc.html

Bore/stroke ratio means NOTHING in the big picture when it comes to high RPM capability. If you're trying to design and engine for racing and you're eeking out every last drop of power, then you do maximize, within reason, your bore/stroke ratio. But for the costs and special parts involved you hit a wall of diminishing returns really hard for the average garage hot rodder real quickly. It's much more cost effective to get better heads or a bigger cam or a better exhaust than it is to worry about exotic crankshafts, rods, and pistons given the comparatively small effect they have beyond what's already affordably available off the shelf.

b1k1w1

next time you decide you need to talk about something you know nothing about pick someone who does not know ether. Nascar engines turn over 9500 rpms because they are balanced to. They use longer rods to build tq they build tq because they stay at top longer and build psi. The lighter crank takes less power to get moving there for revs faster. You use a forged crank to lighten because a cast is not strong enough to be lighten. Cam heads have to do with air flow not rpm the more rpms you have the more air flow you need. So you need heads and cam to feed it that's it. Any bore/stroke can turn high rpms its just how long. Rotating assembly has everything to do with rpms and it must be balanced for the rpms you plan to run. Or it will rip itself apart. Learned from 7 time nascar engine builder winner and one from roush/yates racing nti. And 16 years of doing it who did you learn form. O and there's a lot more you don't know so shutup and learn.

b1k1w1

I'm glad I read those because between my post and there's it shows you just don't understand. They where talking about where power was made in rpm range not how fast it revs witch is what I'm talking about with a smaller stroke. So you give up a little tq to get it to your power range faster. And vvt has to do with getting a flatter power curve throughout rpms. Not how many rpms you can turn, almost every engine today has vvt even ls1. You can turn 9000 rpms with any heads and cam you just won't make any power. The one on rods was for beginners it was guidelines to help you. It did not prove me wrong and you can't find anything because I was right. Sorry to hellbird for rant I just think this will be a cool build

Drac0nic

When you have a virtually unlimited budget to throw into building engines and testing things and 5hp is a huge edge on your competition then yeah, worrying about things like rod length are a good idea. http://rustpuppy.org/rodstudy.htm Although simulated this is a very interesting read about the virtues of long connecting rods. Although they do make a difference, it is very miniscule.

For most people investment in heads and valve train is going to be a lot better choice to make than exotic bottom end parts.

b1k1w1

good post, I'm just giving ideas for him to look into and got bashed. As far as cost 5.7 and 6.0 rods cost the same and the info is already out there. Just need pistons to match. Might only be 1 or 2hp but with boost it adds up. It all depends on what he can reuse and can't. But he won't know till after machine shop. Engines cost a lot so start on paper and go from there. Bottom end can always be done first then top. Weak rotating assembly cost more in long run with boost.

InfernalVortex

iTrader: (4)

Im not saying that lightened rotating assemblies don't help, and that bore/stroke ratios don't help, they do when you have optimized everything else. The problem is that they're not giving up displacement to increase their bore to stroke ratio. They're LIMITED to how much displacement they can use. If they had the choice of running their 358 cubic inch smallblocks, or running a 400 cubic inch smallblock that was the same bore with the same heads/cam/etc, do you think any would still run the 358 just because it can/does turn higher RPMs with the same parts?

We are street guys. We aren't pushing the boundaries of 50 years of performance engineering in a highly-regulated, highly-competitive racing series that has a very stable rule set and a displacement limit.

Bore to stroke ratios are great, but if you're giving up displacement to better your bore/stroke ratio at the expense of cubic inches you're shooting yourself in the foot and doing it backwards. No amount of rotating assembly balancing and lightening is going to be cost effective enough to give you more horsepower per $ than a longer stroke, and the cost margin is probably an order of magnitude different. Bore to stroke ratios will give you more hp per cubic inch(that of course necessitates higher RPM's) if that's what you're after. That's why it's so prevalent in racing, because they're not money-limited, they're displacement-limited. That's also why you never hear about people destroking 327's to 302's to improve their bore to stroke ratio, because it does nothing but reduce torque. Ever heard of a guy with a 383 destroking it to a 350 for more power? The math just doesnt work that way.

If you're building NASCAR engines go for it. If you're building a street engine why spend more on less?

If anything how fast something revs has a lot more to do with airflow. The quicker the engine can get fresh air after the throttle blades open the faster it will rev. Im sure a lighter, smaller, rotating assembly will effect that, but I doubt it has a larger effect than a properly breathing engine. I could be wrong, but this is the kind of thing that is mostly irrelevant in the real world. A properly built high performance gasoline engine will rev quickly regardless of whether it has a good top end or low rotating weight. Ideally it has both.

That's what a stall is for, or a clutch. If you're racing road courses you're never going to be out of your power band. If you're drag racing a clutch dump or gears or torque converter takes care of that. It's a non issue.

The LS1 has never and will never have variable valve timing. Variable valve timing is limited to Generation IV smallblocks, and the LS1 is Gen III. And we're kind of arguing semantics. You can turn an LB9 to 9000 RPM fi you slam it into first gear on the highway, sure. But the valve timing IS optimized for a given RPM range, and the farther you deviate from that the less power you make. Ever notice how dyno graphs go downhill at the end? You quickly get to a point where it's not making enough power to spin itself any faster. Momentum alone can probably spin one that high in neutral, but that's just kind of a pointless exercise. At high RPMs the valve timing isnt right for enough air to get into the engine to make any power to keep it going.

And yes, you're right, VVT flattens out the power curve. But it's more than that too. Compare the peanut cam that makes power from 500 to 4500 RPM to a huge solid roller cam that starts making power at 4,000 RPM and pulls to 8000. The power band is always going to be about the same (For sbc's around 3000-4000 RPM range usually) due to the limitations of having a single camshaft profile, it's just a matter of where you want your engine to run efficiently. Do you want a cruiser that runs well on city roads with highway gears? Or do you want a drag race screamer that goes 150 mph with 4.56 gears? Variable valve timing gives you the advantage of being able to have BOTH (due to how they're implemented, every system has different limitations, none are quite this ideal, but my example is the basic idea). You have one cam shaft profile that operates in the low RPM range, and another that operates in teh high RPM range at wide open throttle. The engine optimizes it's valve timing on the fly to give you the gas mileage and drivability of a small cam and the power of a large cam when you want it. That's why it's such a powerful technology. Without VVT you're limited to a narrower RPM range, with it, you get a much wider usable RPM range. And so yes, you're right, it "flattens the power curve" because it doesnt drop off a cliff after your first camshaft goes beyond its optimal range.

The thing about rod length is, like most hotrodder superstition, it gets kind of ingrained into people and it does make a difference, but the differences are small. If you have a choice it's obvious, but longer and longer rods have serious drawbacks when it comes to piston pin height in the piston, so it's important to be aware of how big the advantages really are (or arent).

http://www.rustpuppy.org/rodstudy.htm

This is a purely mathematical exercise under ideal conditions of course, and with an infinitely long rod modeled you can see the best case scenario of differences.

But due to it being based on real maths and physics, there's no way to derive a real world horsepower number from it beyond inferring it. Horsepower is an abstract concept while torque is a measurable real world concept.

But you can model all the relevant factors that effect torque and RPM, which are what determine horsepower. It's pretty obvious given how small all the relevant statistics change (the biggest difference is piston wall loading which would make me want a longer rod for a road racing engine for instance, but even that is a pretty small change, around 7 percent from a 6 inch rod to a 5.65 inch rod in a 383. Even that is mostly going to affect cylinder wall longevity, and in a high RPM racing motor, it wont come into play very often since these things will run great oil and be torn down on a regular basis.) What is most interesting is the statistic on dwell time which is what you, among most other people, harp on the most.

Do you think that extra .6 percent of dwell time you gain from going to a 6 inch rod from a 5.7 inch rod will make that much of a difference in final horsepower?

I also found this interesting. This fellow seems to be qualified and experienced, and it's this part of his post that I find most interesting:

http://speedtalk.com/forum/viewtopic...9b8aa28e#p1991

I'm skeptical of a lot of these kinds of things mostly because I've seen them proven wrong so many times that I dont trust any preconceived hot rodder superstitions anymore until I see a scientific proof of its advantages. Rods are one of those things taht the numbers dont support the superstition around them, and the lack of published dyno proof over the years also suggests to me that it's mostly a wash.

And this is from a published article by David Reher of Reher Morrison racing engines, and he is clearly way smarter than I am, so here's what he said about it:

b1k1w1

how do you say it mabe made 2hp &2ft of tq it ether did or did not. There is a lot to this subject on how but if you have to buy rods and pistons why not go for the 2hp if its the same price. You have to work with what you have and get the right combo to get the most out of it. Your right ls1 did not but there are ls engines that do. I just hit the one out of habit. Every 1hp and 1ft of tq you find add up and if someone gives you one that does not hurt your engine or cost you any extra try it. I'm not going round and round. I just want to see how it turns out I like the idea. I already brought up the bigger engine and he wants to do 283 so lets see how it turns out.

87hellbird

No one has answered my question yet about if I can use the stock maf? I also am wondering if i can put the maf after the intercooler or if it has to go before the turboes?

Drac0nic

Stock MAF would be a bad idea especially after the turbos. Beforehand it would be a restriction after it would likely explode. They aren't really stout enough for boost. Switch to speed density IMO, you're a lot better off for a turbo system.

b1k1w1

I don't know enough about turbo tpi but it has to go just before throttle body to get correct reading. If its before anything else it will get that reading and not what's going into the engine. They make aftermarket but I did see people using stock. I'm doing same thing on 305 I was told by machine shop to use maf. Sorry can't help more there are some guys on here that have done this best to find and pm them to get correct answer

87hellbird

ok thank you! I just didnt know if you could blow through it or if it only would read stuff that was sucked through it.

87hellbird

Hey everyone its been a little while but I got my engine with dished pistons to where it will be 8:1 compression with the 64cc heads. I am going to go with twin ct26 turboes which people max out at 16psi on 3L and get up to 400-440hp out of one. I was wondering what the psi on my 283, 4.6L, would be with the twins at max just so I know what not to over do it?

87hellbird

I was wondering what injectors I would want for the 2 ct26's? And still no one has replied on the psi max if one maxxes out at 16psi on a 3L what would that be on a 4.6L with 2 of them?

1gary

The question of long rod vs short rod is about as old as Smokey's body is cold.
No one can depict any one source link and say that is the answer.John Lingenfelter Performance's engines yrs ago used 5.85 rods and since has grown to over 6" rods.There are reasons behind why that is so and not just diminishing returns.

Crank's light wt's are a main feature in all high end rotating assembles.It does effect how fast a mechanical assemble can climb threw a RPM range or the "reaction time" of it.Case in point is aluminum rods.Hummm-why??.

There isn't a correlation of a NASCAR engine build and one for drag racing.They are two very different applications requiring two very different end results.

I read 283.................Reallly????.I mean really????!!!.Ya just can suggest and then in 90% of the cases it is just doesn't ever get built.Woops-now 91%.

87hellbird

How is it not getting built? I just got the engine, I am trying to find out the correct turbo for it. I have everything else but the tuning and injectors. and yes a 283 with the turboes and valvetrain i bet ill see 7000+ rpm. not to mention the fastest car in the world ever built was a 283 twin turbo, so it has plenty of power potential!

Drac0nic

I would run the STI turbos before the MK3 Supra ones. They appear to be slightly larger on a quick google search, and they should be able to get you to 600+hp without too much drama I suspect. More importantly they are less likely to have a million miles on them compared to the Supra units as well.

87hellbird

I know they are a bit bigger but That means more lag time and the chance of finding a wrecked or parting out 2 are very unlikely. I dont mind rebuilding the turboes tho.

rmmstnr

Good luck: you'll always have people suggest that you should trash your setup and go with a 350 (and when you get a 350, they'll say 383, then 400, then a big block, then aftermarket block bbc...), but you're building it, so have fun. When they go on about how much cheaper it will be, well there's this: Add the fact that as mentioned, 305's for parts are cheaper than bad dirt and you're golden. The nit pickers with their bore/stroke and rod ratios (they indeed have their applications, but seem a little ridiculous in this case) can pick their nits or educate (which is cool), but seeing as you never said this was to be a land speed record engine that stuff's pretty much irrelevant. Just keep the basics in mind and you'll have a great fun street/strip engine.

Your combo should hold up to boost pretty well, just make sure your valvetrain will hold up to the rpm, particularly the springs. Remember, when you boost an engine, the springs have to fight against the inertia of the valves as well as the boost pressure itself, so if new springs are in the works keep that in consideration. As for a MAF if you are still going with that instead of Speed Density, there are lots of (pricey) aftermarket units made specifically to handle hi-hp apps.The fuel injector sizing comes down to the HP levels you're working towards, so once you have a good idea of your rpm and boost, and therefore power, there's this: http://www.fuelairspark.com/Products...tors%27-0.aspx .

As for nitrous to cool your intake charge, that will indeed work. The problem is, to keep the charge from going fatally lean from the injection you need more fuel, then you just basically raised the BMEP or the cylinder pressures higher. In your case that might be too far for your combo unless you plan on running something other than pump gas (raising BMEP past a certain point means either you use higher octane fuel or you get more detonation, and more detonation is obviously the wrong choice).

Also, spark plugs. Cheap, but ask someone knowledgeable (likely the tuner, they will be very aware of exactly what's going on with your engine) about heat ranges. Basically when adding boost, it's a good idea to go to a "colder" plug. In a nutshell that just means the plug dissipates heat better (hence the term "colder") and will help prevent pre-ignition (sharp edges or other bits in the combustion chamber that become so hot they ignite the charge before the plug sparks). Too cold a plug will cause it to foul, and to a degree lowers combustion efficiency (possibly interesting, but it's the fouling that is relevant in this case).

Good luck, pics would be cool too if it's not a bother!

87hellbird

Thank you i have got colder plugs already for my nitrous setup and on this setup when i run nitrous i for sure will have race gas a guy on craigs has a pair of 350 tpi heads with upgraded springs and guide plates so that is in the works as well. I found out that I cant get a cxhip for this build but that i need to get it dyno tuned so I found Mac auto right near me who does that stuff. All I am waiting on now is the funds to support my build and to find the turboes haha

Ronny

iTrader: (1)

BMEF = brake mean effective pressure (average)

FYI
Now I know two other being BSFC