| Author | Message | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1179 Registered: 11-2002 |
Dr. Tommy, The Throttle Body is the smallest external inlet piece. Direct, bolt on replacement? Never tried to source one, however it's just a 4 bolt pattern unit ...might be the same or simular to something else already in existance and if not certianly rather easy to make. . The FD throttle plate is considerably larger as is the runner to the throttle body. But Ithink Kermit hit on part of the issue here we are tip toeing around...without different CAMS...the flow at a given point in the rpm range will hardly be affected by bigger or smoother holes>>> unless there is a REAL restriction not simply a metering device ie: throttle body. As the 'whole system' (Int, Ex, Heads,valves, throttle body, etc) stands, everything is precisely metered to work seemlessly under a variety of conditions and loads ...nothing can improve what already exists unless one can define one or more parts that are not working fully/correctly to start with. So, as the 'overall' system stands in stock form trying to simply change one part, piece or aspect will only produce nominal improvements and let me qualify a little...>>> = for the Cost. This trying to enhance/improve Ferrari (and especially Inj. 308's) game has been looked at long and hard for a long long time and there really is no cheap or simple way (short of nitrous) to make major gains without Major Changes and Major Bucks. Ferrari just didn't leave much free or easy HP on the table like Porsche and other makes (which is why floor mats are so popular ;-)). | ||
| Matt Morgan (Kermit)
Junior Member Username: Kermit Post Number: 121 Registered: 8-2001 |
Ben, on the 2V versus 4V stock, @ .300" lift Th 2v flows 75CFM going to 86 CFM @ .400 on the intake. The 4V flows 96CFM and 95CFM at he same lifts on the intake. The Exhaust on the [email protected] is 63CFM then goes to 74 @.400, while the 4v numbers are 85 and 94 at the same test lifts. As you can see the 4Vflattens out on intake flow stock, yet the 2Vcontinues to climb. The 4V exhaust does better however. Please note, these are baseline figures, and are not factored for temperature differential, which is the differance in temp before and after going thru the port. I have found that porting will change the 4V intake to continue to rise, instead of leveling off. And of course flowincreases across th board for both types as they are ported.I like to pay particular attention to the low and midlift flow #'s , as they have a very big effect on how well the column of air starts to move, in or out. | ||
| Dr Tommy Cosgrove (Vwalfa4re)
Member Username: Vwalfa4re Post Number: 885 Registered: 5-2001 |
Is the throttle body opening larger or smaller then the sensor plate on a 4V engine? If it is smaller isn't this the first place you need to start working on before the intake manifold and finally the heads? And again, is there an aftermarket throttle body that is bigger for the 4V's or do you need to bore your's out? BUT? wouldn't this be a waste of time anyway if the sensor plate is SMALLER? Just asking, I have no idea, you guys are the experts here. JRV? | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1177 Registered: 11-2002 |
>>With the increase in air you will need the fuel, which you simply enrichen the mixture with the 3mm Allen screw,<< That's only an Idle Mixture adjustment...and if you "increase air flow" at idle...the engine will simply 'idle higher' (after mixture corrections). And to increase idle air flow you won't need to polish any ports...;-)....you could just turn the idle speed screws. | ||
| jeff ryerson (Atheyg)
Junior Member Username: Atheyg Post Number: 198 Registered: 8-2002 |
With the increase in air you will need the fuel, which you simply enrichen the mixture with the 3mm Allen screw, this will enrich the mixture throughout the airflow band If flat spots or hesitations are detected the demand for more fuel can be met with a load sensing system fuel-pressure regulator which are fully adjustable for system pressure This from Ben Watsons book on Bosch Tuning | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 419 Registered: 11-2002 |
Art, what are the units on the BMEP data? I spoke with Dynojet the other day. The rep stated that it's the operator who ultimately determines the results via correction factor. Plus, this is also a pride thing, and the operator knows that if his data doesn't correlate that his customers will go somewhere else where numbers come up larger. So he could punch in 16% when scientifically, he should use 18%. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1176 Registered: 11-2002 |
>>>How does the inj system deal with this air increase? << If there was an increase (which there wouldn't be without moding upstream of the head itself) the metering capabilities of the FD would compensate. The way the CIS works is, fuel is delivered in volume by position of plate that is lowered by incoming air volume. So the metering is already 'factored' in by a number of constants (fuel press., injector size, slot configuration, etc). To increase air flow certian things would need changing, Throttle Body hole size, harder suction at given rpm, increased force on incoming air... Simply making a hole bigger or smoother by itself does not neccesarily increase Air Flow or Volume at a given rpm, other factors are neccesary to "increase volume". Porting an engine is a series of changes not just one. Although we tend to think of just head ports when talking about porting & polishing. | ||
| Russ Turner (Snj5)
New member Username: Snj5 Post Number: 43 Registered: 2-2003 |
"I'm not a mechanic, but I play one on tv...." The kjet airflow sensor plate would sense the increased air current after porting and correct accordingly. I've been told that there is a lot of range left in the original fuel distributor delivery, which is why the kjet works well with forced induction (higher flows ). The big problem as I understand it with the kjet system in the resistance to flow from the components that the engine has to suck air past. To begin to run lean, the airflow would have to be so high that it is beyond where the airflow sensor plate pegs its travel. Once I spoke to Nick about a Mondial that had substantial hp increase from port/polish keeping the original injection. Perhaps he or Kermit could comment if applicable. Of course, I could be totally wrong. "Dammit Jim, I'm a doctor not a fluids engineer.." best rt | ||
| Dr Tommy Cosgrove (Vwalfa4re)
Member Username: Vwalfa4re Post Number: 883 Registered: 5-2001 |
Another thing I forgot to ask: How does the inj system deal with this air increase? wouldn't the 2V's just run lean as hell? The 4V's have lambda but would that alone help richen things up? | ||
| arthur chambers (Art355)
Intermediate Member Username: Art355 Post Number: 1109 Registered: 6-2001 |
Mark: I've gotten into the top 10 there 2 times. Once in the superbike race (1979 I think), and once in the BOTT. I was lucky not to break anything in 89. Art | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 441 Registered: 5-2002 |
Art, maybe. I know that saw a write up using 5 new cars on a dynojet, they were looking at premium vs race gas I think. The interesting thing was that al the cars (US & Japanees) came up 25% -33%(honda) under the claimed HP, with 16% the accepted correction for crank to rw for transverse layout. The ferraris I've seen #s on are within a couple HP when the 16% correction is used. A buddy of mine drag races and the HP calculated using the mph at the 1/4 lights also matches the dynojet #. The day I had my car on the dyno, there has a C5 vette there with headers, free flow exhaust, cold air intake. He made 304 HP, which gives him 352 crank, which should be about right. My car made 305...he was very upset  I was racing at daytona, I blew the trans going into the horseshoe locking the back wheel and sending me over the handle bars. I've never had good luck there. I had to rumage the swap meets to get 1 gear working again to enter the dyno-shootout, getting the drum rolling with only high gear was a bear. | ||
| arthur chambers (Art355)
Intermediate Member Username: Art355 Post Number: 1107 Registered: 6-2001 |
Mark: The formula for maximum theorical power is (I haven't looked it up, this is from memory) BMEP= 7.92x10to the 5th power x HP ---------------------------- RPM x CI As you can see, if you can fill the cylinders to the maximum, you can get pretty good power. However when the BMEP gets too high, the vehicle becomes difficult to ride or drive, because you have cammed it way too much. That's why I used 160 for the BMEP number, which is a relatively high number for a street vehicle. A number such as 180 would be such that the vehicle would not be street worthy and very, very cammy. In my experience the dynojet numbers are about 25% high over a true dyno number. Using that correction figure, then the claim of 375HP would be reduced by 75HP, for approximately 300HP which isn't too far away from the 280 that I used. All that assumes that you only turn the engine at 8500. If you are willing to turn it higher, and the flow numbers will fill the cylinder (and empty it) you can get more power, but you drastically shorten the life of the engine with the extra RPM. I'm not sure what the feet per second number is for the 308 at 8500, but I would be that over that number, you would need special rings to make sure that you got a good seal. By the way, were you riding the XR at Daytona? One of my favorite tracks. Only place where I've only fallen once (kink after the horseshoe in 89) Art | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 440 Registered: 5-2002 |
Art, The carb'd 2Vs make 240 stock and it the cars I've seen dyno'd support the claim (on a dynojet though). With more cam, compression, ect they make more, I don't know where they get, but the claims I've seen are between 320-375. 120%-125% is the VE I would expect to see on a well prepared machine, those number are in line with that. | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 439 Registered: 5-2002 |
Art, It is an XR. 110 is in dyno-shoot out trim (94&95 class winner in daytona), it was just under 100 prep'd for the track. On the power loss when they went to injection, does anyone know, are the cams the same? I think my service manual says yes, but I think it's lying. I have read the the injection doesn't like overlap, and the peak power dropping from 7500 to 6800 says less duration. I found when I had my 4v apart that even though the book said duration at .020" lift, when I put on a degree wheel, it was the total # and was 16 degrees less at .020 lift. I called a couple dealers, but didn't find anyone who ever did the cams with a degree wheel so they didn't know. I think that is what drove ferrari to the 4v head, they could get the flow without the duration. | ||
| arthur chambers (Art355)
Intermediate Member Username: Art355 Post Number: 1104 Registered: 6-2001 |
Randall: You can't trust the Dyno jet numbers: there high. Assuming a 160 BMEP (highest number you can exepct from a streetable engine) then the theorical maximum about be 285 HP, if the BMEP was 180 (a number that is rarely seen, and only on race vehicles, implies 13+ cr, etc) then the absolute theorical number would be 353.5 at 8500 rpm. An example of Dynojet accuracy: My 1977 triumph which has been extensively reworked and makes about 2xs a stocker makes 69HP on a Dynojet. It makes 50.1 HP on a Factorypro Dyno. In the motorcycle industry the dynojet is the standard, not because it produces accurate numbers, it doesn't. It is consistent however, i.e., make a change and it will accurately report the difference, allowing you to tune for greater performance. You just can't trust those numbers. I'd take those numbers and claims with a very large grain of salt. If I had to bet, assuming that they were able to fill the combustion chamber compeletly (which I strongly doubt, having seen the photos of the port on this thread) that this motor may make 250HP. The above is just my opinion, having racing 2 valve motorcycles with a head similar to that of the Ferrari. I raced them, tuned them, modified them for approximately 20 years. Art | ||
| Paul Sloan (Sloan83qv)
Member Username: Sloan83qv Post Number: 520 Registered: 3-2001 |
I would think that the first air flow restriction on GTSI and QV's would be the K-jetronic system which regulates and restricts air flow long before you get to the throttle body. Look at the numbers, there was an approx 40 hp loss from a 1979 308 to the 80+ 2 valve car and an approx 40 hp gain from the injected 2 valve to the injected 4 valve in 83. The single largest robber of HP is the injection system! | ||
| jeff ryerson (Atheyg)
Junior Member Username: Atheyg Post Number: 197 Registered: 8-2002 |
The book, "How to Tune & Modify Bosch Fuel Injection" by Ben Watson references a Weber big bore throttle body kit which resulted in a major HP gain, I dont know compatabilty with Ferrari | ||
| Dr Tommy Cosgrove (Vwalfa4re)
Member Username: Vwalfa4re Post Number: 872 Registered: 5-2001 |
Are larger throttle bodies available for the 4V's aftermarket or do they have to be machined along with the head? I was assuming the intake manifold would need to be enlarged along with the head. I am familiar with this from my H2O-cooled VW's. I would install a larger plate and intake runner to the manifold, port the manifold, and install a larger throttle body. Otherwise I could not get enough air to blow into the head. | ||
| arthur chambers (Art355)
Intermediate Member Username: Art355 Post Number: 1101 Registered: 6-2001 |
Matt: The guy that I use for porting, Ken Augustine, is the one who did the original D shape port design for Harley. I am amazed that you got 110 HP from your Harley. I'm assuming its an XR750. the best one I've heard of is Mert Lawill's and it only made 100. Art | ||
| Tom Bakowsky (Tbakowsky)
Member Username: Tbakowsky Post Number: 280 Registered: 9-2002 |
I agree 100% JRV. I would much rather start with an EFI system, a larger throttle body and maybe even a custum intake plenum and runners before doing any porting. The injection system alone on these cars is very restrictive. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1168 Registered: 11-2002 |
Without changing the induction system on 308 Injected Engines any gains from porting will be nominal. The restriction starts at the FD Plate and continues thru to the Throttle Body. Consequently the "first" restrictions must be eliminated before downstream flow improvements would have meaningful effect. | ||
| Ben Millermon (Brainsboy)
Junior Member Username: Brainsboy Post Number: 154 Registered: 5-2001 |
Kermit I know you dont like to give flow figuers but could you comment on an average of what a normal 2v head and 4v head flows from the factory | ||
| Matt Morgan (Kermit)
Junior Member Username: Kermit Post Number: 120 Registered: 8-2001 |
Dr Cosgrove, I would recommend staying withthe stock 4V valve sizes. I port to templates that are the result of my flow bench work. With the exception of the exhaust, which I stay with he stock gasket as a template. There is plenty of room there to open it up as it is, and the amount of work necessary to take advantage of larger than stock exhaust ports is not usually worth the effort. The headers would have to be done then too, in order to not neck down after leaveing the heads. On the opening up issue, I do each to the Owner/cars needs. A "Town Car" doesn't need an all out port, etc. | ||
| Dr Tommy Cosgrove (Vwalfa4re)
Member Username: Vwalfa4re Post Number: 870 Registered: 5-2001 |
So with the 4V's the valve size should remain the same but porting/polishing is the way to go? Do you have enlarge the intake and exhaust openings as well to match the larger ports? | ||
| Matt Morgan (Kermit)
Junior Member Username: Kermit Post Number: 119 Registered: 8-2001 |
OK, I can't answer all the questions and get my "nap", which is what I refer to as my nights rest.(LOL). I'll be doing the same porting a I did for the Forza, but with better to the end user prices. Bear in mind, Nick paid WHOLESALE, then stepped that up for his cut. On the price topic, I plan to offer a Street version of the porting, with about 80% of the flow, but not as highly polished as the top of the line. As I see it, not everyone wants the big flow #'s (with their price), and the polishing takes actually longer than the porting does. Hopefully within the next month I'll have my new site up, and ther is a lot more perfomance stuff coming out then. And Mark, as a rule I don't give out Flow bench #'s, as if you are as familiar with them as you sound, you know how easy they can be "doctored". We can E-mail later on that topic,hopefully after the site is up. And Dr Cosgrove, the 4V heads really wake up when ported. I had the opurtunity to demonstrate Christian Keinle's Mondial 3.2 heads with him present. As he can verify, the stock 4V flow levels off about .325 lift, with very little gain above that. | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 436 Registered: 5-2002 |
Matt, What are you getting for flow #s? My porsche gave 142 cfm @ 10" h2o to fill a 460cc cylinder, my harley race bike flows 154 cfm @10" h2o into a 375 cylinder (it makes 110 HP from 750cc) - both include intakes,carbs and filter. I never measured the ferrari head because it looked like the factory did a pretty good job on them and with the supercharger pretty good is fine. | ||
| Randall (Randall)
Junior Member Username: Randall Post Number: 159 Registered: 1-2003 |
KERMIT What do you charge for porting compared to that guy? What all do you do? I've heard people talk positively about your work, so I was just curious what you do. | ||
| Dr Tommy Cosgrove (Vwalfa4re)
Member Username: Vwalfa4re Post Number: 868 Registered: 5-2001 |
Matt, Is porting/polishing/oversized valves possible with the 4V heads and, if so, what increase in power can be expected? | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 435 Registered: 5-2002 |
Matt, I�ve never worked of 2v ferrari heads, so you may be exactly right. The experience I have is with porsche and harley. They both respond about the same, reshaping the combustion chamber to a bathtub shape and dual plugs allows them to tolerate about another .5 on the compression without detonating, but a lot of care is required to prevent a shrouding problem. Also, both engines have a separate head for each cylinder, so warping is not a problem. I don�t know what would happen on a ferrari head, but I�m sure even welding in fixtures there would be some warping, when or not it could be remachined, I don�t know. I would believe that throwing away the stock plenum is that best place to start. I�m still not sold that going back to carbs is a good idea, but it does work and is cheaper 8 throttle bodies. | ||
| Matt Morgan (Kermit)
Junior Member Username: Kermit Post Number: 115 Registered: 8-2001 |
First off , Nick needed someone to do the porting since we parted company, as I was doing it all. Secondly, they claim to install oversize valves, and in reality, the exhaust may be opened up 1mm to 1.5mm before problems arise on valve contact on overlap. Mark, as I have spent many hours on the Flowbench with 308 2V heads, I can tell you that weld buildup isn't the answer on these heads. As the chamber is a shallow dish, The amount of material that would have to be added to increase compression significantly would shroud the valves, reducing flow. This is based on clay modeling, cc'ing etc. An extensive study. Then what about warpage in the cam journal saddles with that much heat? And Jeff, you are right, the stock injected intake Plenium and runners is restrictive. I baselined Stock 4Vrunners, Ported ones, then Pauls 48mm Weber runners. Pauls handsomely outflowed either. This tells me that we are aproaching the limits setby the total square inch area of valve opening available. Incedentally, the 4V has a considerable bit more open area than the 2V. In closeing IMO as a builder, I feel that the #'s are more likely from the marketing department than actual Dyno #'s. As to Farming work to Nick: Nick does sales, not porting. As I have known him (10 years now) he has yet to make a single chip on the porting bench. | ||
| Ben Millermon (Brainsboy)
Junior Member Username: Brainsboy Post Number: 149 Registered: 5-2001 |
hear are some photos of the porting.   | ||
| Ben Millermon (Brainsboy)
Junior Member Username: Brainsboy Post Number: 148 Registered: 5-2001 |
Im with Mark for the cost of it all, I would rather go with a supercharger then to spend 5000 on the heads. I ported my heads a little bit, but after looking at them closely, there just isnt enough meat in the ports to open it much more then they already are. Besides people who spend 5000 on porting usualy go with larger valve sizes to allow more airflow, and there isnt enough room in the heads for oversized valves. | ||
| jeff ryerson (Atheyg)
Junior Member Username: Atheyg Post Number: 194 Registered: 8-2002 |
More air into the motor is what gives the power increase Polish and port job should do about 10%-15%, where you will get the biggest gain is widening and polishing the throttle body on FI cars | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 434 Registered: 5-2002 |
350 HP @ 8500 sounds about right to me. I had a 2.8 porsche making 360 @8500 (on a dynojet)on pump gas. It required extensive welding on the heads and combustion chambers, dual plugs, ridiculous cams and 11:1 compression. I think I spent about 200 hours on the heads, so $5k would be cheap for that kind of work, then another $5k -$8k to get the other parts so you can use the high flow heads and make it run right. I don't think I would ever do it again, forced induction is the way to go if you're trying to get more than 20% or so increase | ||
| Dr Tommy Cosgrove (Vwalfa4re)
Member Username: Vwalfa4re Post Number: 867 Registered: 5-2001 |
I would like to hear Nick chime in on this... | ||
| arthur chambers (Art355)
Intermediate Member Username: Art355 Post Number: 1094 Registered: 6-2001 |
From what I've seen over the years, the problem with Ferrari 2v heads is that the bottom of the intake and exhaust ports is too close the combustion chamber. That means that the air on the way in must make too sharp a turn, and you end up with breathing only half of the intake valve. A way around that is to weld up the port, and make the shape of the intake into a D shape. That will widen the radius of the turn the air needs to make, and if there is enough side material to ensure that the area of the port is unchanged, if you can raise the floor of the port enough, you can make a 2v head flow as well or better than a 4v. If these guys are doing that, and have found how to keep the flow velocity up, then you probably can get pretty good increases in the power. 5k sounds about right for that kind of work. You would also need a revised camshaft to make all that work, along with a tuned exhaust. HOWEVER, you cannot get 350HP from a 2v, 3 liter engine at 8500 RPM without turbocharging. You can get 350 HP from a 3 liter engine, but you will have to turn it higher to get that power. I bet they got those numbers on a Dynojet, which are usually a little generous on its readings. Art | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 433 Registered: 5-2002 |
Read carefully too. The sight says the engines uses their heads, not that bolt on heads make 350 HP. The only way to shift the rpm band up like that is more durtation in the cams and when you do that you need a couple points more compression. I've see some pretty big HP increases from porting alone on some non-Ferrari engines that have really bad heads to start with, but Ferrari heads are quite good already. I would expect not more than 10% with 5% a better guess from porting alone. It is not where I would spend $5k to improve performance, the FI system is the problem, it doesn't flow and doesn't allow cams with enough duration to be used. Change to an EFI system and carb engine cam grind and you'll pick up 20-30 HP I would guess or just throw on a turbo or supercharger and gain 100 HP. | ||
| pete gorrell (Rufus)
New member Username: Rufus Post Number: 32 Registered: 2-2002 |
Note this guy is in the UK. Any FC members from Blighty know of him? | ||
| Jerry W. (Tork1966)
Member Username: Tork1966 Post Number: 560 Registered: 7-2001 |
If he is after work himself, why is he letting Nick advertise on his site? Is he farming the work out to Nick? | ||
| Dr Tommy Cosgrove (Vwalfa4re)
Member Username: Vwalfa4re Post Number: 865 Registered: 5-2001 |
Who is that guy? | ||
| Ken Ross (Kdross)
Member Username: Kdross Post Number: 285 Registered: 2-2002 |
There is a guy in the Phila, PA area that has done this to a 2V. For $5K he will somehow modify the head or do something like port and polish them. I understand that the results are substantial, but not 350hp. I am told that for your $5K a 2V will be slightly faster than a 308QV, so figure about 40hp-50hp increase. | ||
| Randall (Randall)
Junior Member Username: Randall Post Number: 157 Registered: 1-2003 |
Has anyone here actually done this to their car? This site: http://www.geocities.com/spperformancecentre/Ferrari-Power.html Says they can pull almost 350HP out of a 2v engine by altering the heads. That seems like a pretty big increase, so big I find it hard to believe. It doesn't mention any other alterations to the engine. If they can do it, it seems like a deal. |