Long tube power gains?

bb97gt

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So i just switch to E85, it made just under 650rwhp at 19lbs. My current set up is stock manifolds, BBK off road x pipe, and Magnaflow CB. What gains are to be seen to switching over to a set of BBK long tubes and off road x? Going full 3 inch is not an option at this point, just don't have the coin.
 

98 Saleen Cobra

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At that power level I would say a decent amount. How much exactly?? I'm not 100% sure..
 

RamboCobra

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you dont have to be 3in mine are bbk 1 5/8 long tubes 2 1/2in off road X and 3in cat back there wroth it and they make even more power with after market blowers.
PS: they sound awsome:rockon:
 

Crackerballer

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You didn't tell us your goals. At your power levels, of course they will help, but do you plan to ever go to a smaller pulley and try to squeeze more power out?

I would look into a set of 1-3/4 or 1-7/8 ARH headers and a full 3" system. It can be done for less than $2,000.
 

bb97gt

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I don't really have "goals", just sold a few parts and have a little bit of extra cash sitting around. I plan on going turbo within the next year or two so I'm not bothering going 3 inch right now.
 

Crackerballer

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If you are going turbo, that is all the more reason to get a 3" catback and not get headers, unless you are going to run dumps/cutouts. I'd check the market section for any used set of longtubes and midpipe and just throw them on there for the time being then.
 

GodStang

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the headers might gain you a huge whopping 5hp, headers look and sound cool though. wasted time and dough

There has been before and after dynos of LT installs gaining 25-45rwhp on TS over and over and over again on this site along with other sites. Depending on power levels. At his level now I would not be surprised if he got around 30. Is it worth it? Well that is up to him.
 

cobra=trouble

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There has been before and after dynos of LT installs gaining 25-45rwhp on TS over and over and over again on this site along with other sites. Depending on power levels. At his level now I would not be surprised if he got around 30. Is it worth it? Well that is up to him.
i do know that you can feel the differance in 40 rwhp.
when i run my 93 tune i got 600 with 104 gas i got 640 ,when i go back to 93 gas after that my car doesnt feel as fast.

so youre not going to feel 5 to 10 rwhp at all.

if i got the coin iam going to do them . i do have a T/S with A 3.700 bore, im hoping i can pick up at least 40 more , plus a little more the the additonal cubes.
and E85 later.
 

SlowSVT

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There has been before and after dynos of LT installs gaining 25-45rwhp on TS over and over and over again on this site along with other sites. Depending on power levels. At his level now I would not be surprised if he got around 30. Is it worth it? Well that is up to him.

45 hp :dw:

Keep in mind this coming from a guy who never saw a mod he didn't like :rollseyes

All your post should come with a disclaimer.

Gains between 5 - 10 hp is what you will typically see with LT. Once your cross the 600 hp level gains with headers start to climb.
 

04SolidSnake

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So i just switch to E85, it made just under 650rwhpat 19lbs.

45 hp :dw:

Keep in mind this coming from a guy who never saw a mod he didn't like :rollseyes

All your post should come with a disclaimer.

Gains between 5 - 10 hp is what you will typically see with LT. Once your cross the 600 hp level gains with headers start to climb.

Even on a fairly stock car, you are talking about peak gains of 5 - 10, but if you look at power under the curve (which is waaaaaaay more important), you will see some excellent gains..

That is why if you see 2 identically modded Terminators, one with LTs and one with stock manifolds, the LT car pulls HARD. Much harder than the 5 - 10 whp gain would indicate.

For the cost vs HP gains, you're further ahead buying other parts first on a stock terminator, but long tubes are an excellent modification any way you look at it.
 

Kwik03DSG

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Even on a fairly stock car, you are talking about peak gains of 5 - 10, but if you look at power under the curve (which is waaaaaaay more important), you will see some excellent gains..

That is why if you see 2 identically modded Terminators, one with LTs and one with stock manifolds, the LT car pulls HARD. Much harder than the 5 - 10 whp gain would indicate.

For the cost vs HP gains, you're further ahead buying other parts first on a stock terminator, but long tubes are an excellent modification any way you look at it.

I will vouch for this. I raced my bro Adam in his cobra. Only difference between his and mine is 3.73 gears and bbk LT headers. I got yanked by 2-2.5 cars from 40-140. Anyone who says LT's isn't worth it, ESPECIALLY on a car that makes 650 like yours OP is a fool. Point blank period. long tubes are well worth it at your power level.
 

FAsnakes

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the headers might gain you a huge whopping 5hp, headers look and sound cool though. wasted time and dough
+1 when i added LTs i really didn't see any gains.. IMO complete waste of time and $$.. Not worth the trouble.
 

SlowSVT

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Even on a fairly stock car, you are talking about peak gains of 5 - 10, but if you look at power under the curve (which is waaaaaaay more important), you will see some excellent gains..

That is why if you see 2 identically modded Terminators, one with LTs and one with stock manifolds, the LT car pulls HARD. Much harder than the 5 - 10 whp gain would indicate.

For the cost vs HP gains, you're further ahead buying other parts first on a stock terminator, but long tubes are an excellent modification any way you look at it.

So what you’re saying is the VERY restrictive factory cast iron manifold actually works pretty well at high RPM where they need to move large quantities of gasses very quickly compared to a VERY low restriction set of long tube headers that actually scavenge the exhaust? But for some reason the factory manifold doesn't work very well in the mid range :dw:

That seems almost backwards!

This post is mostly conjecture with no real data just a generalized statements. MM&FF mods for mods series articles on the Terminator engine and did a battery of very careful test confirmed on an engine dyno. One was a long tube vs. the factory manifold and both graphs almost mirrored one another and the difference was 10 hp at top end. I have the article and can dig it up for you if you would like.

There was a post on here years ago where a guy did the exact same thing and ran "before & after" dyno runs and was pissed as hell after recording a 5 hp difference after spending 12 hours and $1000 :cuss:

There are countless threads on this site and the conclusion is headers don't work very well on a mildly hopped up Terminator engine. In an NA applications you will get better results. All headers do is help rid the cylinder of spent gasses and reduce the pumping losses somewhat but having a blower in front of the everything does most of that. In the end what matters is having the least amout of unburnt gasses in the cylinder to maximize power input. If the blower can purge most of that during valve overlap then you have achived that goal.

Something tells me you are running LT's and the results were amazing!

Running E85 at 650 hp the OP would probably be well served getting a set of LT's IF he was planning on keeping it. But he plans on going to turbo where that money would be better spent elsewhere.
 

04SolidSnake

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So what you’re saying is the VERY restrictive factory cast iron manifold actually works pretty well at high RPM where they need to move large quantities of gasses very quickly compared to a VERY low restriction set of long tube headers that actually scavenge the exhaust? But for some reason the factory manifold doesn't work very well in the mid range :dw:

That seems almost backwards!

This post is mostly conjecture with no real data just a generalized statements. MM&FF mods for mods series articles on the Terminator engine and did a battery of very careful test confirmed on an engine dyno. One was a long tube vs. the factory manifold and both graphs almost mirrored one another and the difference was 10 hp at top end. I have the article and can dig it up for you if you would like.

There was a post on here years ago where a guy did the exact same thing and ran "before & after" dyno runs and was pissed as hell after recording a 5 hp difference after spending 12 hours and $1000 :cuss:

There are countless threads on this site and the conclusion is headers don't work very well on a mildly hopped up Terminator engine. In an NA applications you will get better results. All headers do is help rid the cylinder of spent gasses and reduce the pumping losses somewhat but having a blower in front of the everything does most of that. In the end what matters is having the least amout of unburnt gasses in the cylinder to maximize power input. If the blower can purge most of that during valve overlap then you have achived that goal.

Something tells me you are running LT's and the results were amazing!

Running E85 at 650 hp the OP would probably be well served getting a set of LT's IF he was planning on keeping it. But he plans on going to turbo where that money would be better spent elsewhere.

Yes, 5-10 hp peak on an other wise stock Terminator.. Again, there are plenty of places to spend your money before doing LTs, however people read the 5-10 peak HP numbers tossed around, and fail to realize a) Your power under the curve across the power band is going to be much better, b) Once you start throwing ported blowers, or Twin Screws on the peak gains of LTs climb pretty quickly.
 

sassafras

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I hope to answer this question rather soon. I've got my dyno graphs from last March when I was going through stock manifolds with a whipple pushing 21 psi and E-85. I'm installing my headers now and I'll be re-pullying the whipple to keep the same boost level. Everything else will remain the same. We'll see what the true gains are here in about a month.
 

greengt88

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they're worth it once you hit about 525-550rwhp, not necessary though but thats when the gains start to show, you'll need atleast 600rw for them to shine.
 

vladSVT

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I gained about 5-7rwhp if I remember correctly from going longtubes (On my old 03 cobra with stage 4 port eaton). But I had stock catback at that time so the setup was choked, I would expect probably around 8-10rwhp gains on an eaton car.
 

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