Guest bumpercar240 Posted September 8, 2004 Share Posted September 8, 2004 Just wanted to ask your guys opinions on where to plug an external wastegate on the stock manifold and if it is even a good idea to do so. I've seen some pics with an external on the stock, but my C. Bell book says its not a good idea if the manifold is not equal legnth. Just wanted your opinions, TIA. Jon Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 8, 2004 Share Posted September 8, 2004 Why do you "need" an external Wastegate? JeffP went to 500HP and still had the stock wastegate actuator on the car. After changing to the external unit, he started wondering if he "needed" it at all! And in fact is considering bolcking it all off to check the performance of the car with his 600HP tune just to see if it was possible without all the money and fuss. See, he laments swapping to the External before even TRYING to make his HP number without it. So I would say unless you are headed north of 500HP, an internal will do you just fine, and save you considerable $$$ and Headaches! Quote Link to comment Share on other sites More sharing options...
Clifton Posted September 8, 2004 Share Posted September 8, 2004 Unless you are going to a full T4, I too would have to wonder why you would want to use an external wastegate. internals are cheap and easy to make adjustable and are dead accurate even at 20 psi. Externals tend to spike with the MBC's or you can use an expensive electric controller. I originaly pulled my wastegate exit off the number 6 port. Might not have been Corky approved but it worked fine. I ended up moving the motor back 2" and had to pull it from the bottom in the center of the manifold. To do again I would just run the wastegate under the turbo, but wanted easy access even though I have never needed to get to it. On my 7M I pulled it right behind the T4 flange I welded on and ran it below the turbo. 7M cast manifold Looking up from underneath the car. Quote Link to comment Share on other sites More sharing options...
auxilary Posted September 8, 2004 Share Posted September 8, 2004 I think you should keep an internal unit unless you absolutely need teh external (which I don't think you do). if you do decide to go external, it should be as close as possible to the turbo, and in the most direct flow of exhaust gas (ie. no 180* turns) Quote Link to comment Share on other sites More sharing options...
Guest bumpercar240 Posted September 9, 2004 Share Posted September 9, 2004 Tony, we went over this at the last Inland Empire monthly Z meet. I did what you said and read up on JeffP's website on zcar.com and it wasn't some ghetto rig'd junk yard turbo that you made it out to be or so I understood from you. You know him personally and you know what he's done under the hood. According to the website he switched the manifold and is now running 46mm tial wastegate and I'm trying to follow in his direction not so much as 600-+ hp but around 400-500hp and it would seem to me that external is the way to go as far as reliability when flogging the motor at a drift event and or SpeedTrial track event. I've seen pics of external wg on the stock manifold and was hoping to get away with not having to buy an aftermarket exh. manifold, but if I can't I will buy an aftermarket piece. So my question would be can I get away reliably with the stock manifold or should I purchase an aftermarket piece from a reputable source? and yes I'm planning on running a T4 of some sort, not determined yet, but those are just plans and plans can change. TIA. Jon Quote Link to comment Share on other sites More sharing options...
Guest bumpercar240 Posted September 9, 2004 Share Posted September 9, 2004 Thanks for the engine pics Clifton its got me thinkin'. Nice engine bay as well. Jon Quote Link to comment Share on other sites More sharing options...
Xander Posted September 9, 2004 Share Posted September 9, 2004 Guys, Keep in mind that the wastegate has nothing to do with maximum horsepower figures. You could run a t3/t4 without a wastegate at all and run 25 PSI or something like that. The wastegate is there to let you be able to run lower PSI even with a big turbo. I seriously doubt that the internal wastegate can vent off enough exhaust gas to let me set maximum boost at 10 PSI. you would get serious some boost creep. I for one don't want to run maximum boost ALL the time. comments anyone? Quote Link to comment Share on other sites More sharing options...
jgkurz Posted September 11, 2004 Share Posted September 11, 2004 All, the difference between an internal and external wastegate is boost stability. It has nothing to do with peak HP. I have an internal wastegated L6 making decent power and I struggle to have consistent boost throughout the RPM range. I have modified my internal WG extensively and it still doesn't work as well as a external type. If I had an unlimited budget I would go external in a second. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted September 11, 2004 Share Posted September 11, 2004 An external wastegate can help to produce power in a couple of ways that I can think of quickly if prouperly designed. 1. Better location to pull the waste gas from. 2. Can be divorsed and not run back into the exhaust system. This would help with flow of both the main system and the wastegate system. 3. Does not dump the waste gas back into the downpipe causing turbulance and reduced flow. Thats what I can think of while I'm at home on lunch. Having said all that I will proubly will run the internal wastegate for an increase of another 100hp or so from where I am now. Which should be in the high200's low 300rwhp range. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted September 11, 2004 Share Posted September 11, 2004 Quote Link to comment Share on other sites More sharing options...
v8dats Posted September 11, 2004 Share Posted September 11, 2004 man joel that is one beautiful piece of iron u got there!! cant wait to see it! Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted September 11, 2004 Share Posted September 11, 2004 You can't tell me this wastegate can't help improve flow over almost all internally gated waste gates. That's just beautiful man...... Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted September 11, 2004 Share Posted September 11, 2004 man joel that is one beautiful piece of iron u got there!!cant wait to see it! Did you get my last email? I had a bad day fri. and didn't get the manifold sent off to you. I promess it will go out to you on Mon... And... yes' date=' that w/g did help when I had it mated up with a T-61/ .58 P trim. The trick I think is that I had it venting with its own pipe to the atmo... [img']http://www.superkaos.com/phpbb/images/smiles/a.gif[/img] Quote Link to comment Share on other sites More sharing options...
v8dats Posted September 12, 2004 Share Posted September 12, 2004 hey joel thats not a problem actually i would rather wait till this hurricane blows over b4 u ship it 8) Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted September 12, 2004 Share Posted September 12, 2004 2. Can be divorsed and not run back into the exhaust system. This would help with flow of both the main system and the wastegate system. 3. Does not dump the waste gas back into the downpipe causing turbulance and reduced flow. And... yes' date=' that w/g did help when I had it mated up with a T-61/ .58 P trim. The trick I think is that I had it venting with its own pipe to the atmo... [/quote'] See what I mean. Practical experience here from Joel. Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted September 12, 2004 Share Posted September 12, 2004 I fought with boost creep/instability with the ford/turbonetics internal WG for a couple years. I solved the problem with a Tial 38mm external gate that is now bolted to my turbine housing. I bought a 5 bolt SS flange and bored out the WG hole to the same ID as 1.5" SS thinwall pipe. A 45 deg bend and a little piece of straight pipe and Voila - no more WG problems. With the 38mm gate - I can run any boost pressure without instability or creep. It will clear the stock intake manifold and I have it routed back into the DP, but you could run it open to the atmosphere. Having driven a friends GSXR1000 with a ball-bearing GT25 and an open dump, no way is that going to happen in my car. Even with a helmet on - it makes a pile of racket. We won't even mention his bosses 'Busa with 540 rwhp (GT3040). I can post pics if you like, but I am overseas for 5 more weeks, so it will be a while. It is a less-costly way to go external and involves less work, IMHO. Doug Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted September 12, 2004 Share Posted September 12, 2004 As far as noise goes, I honestly didn't hear any noticeable difference from my w/g being open vented. Maybe because of the stainless Borla exhaust, but I doubt it. It just wasn't any louder than normal to me... Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted September 12, 2004 Share Posted September 12, 2004 Well, on the bike it scared the crap out of me the first time it opened. Then again, the dump pipe is about 4 inches from the WG and it is right at your right toes. Actually - The bike just generally scared the crap out of me. 224 rwhp with no extended swingarm. It kind of re-calibrates your whole perception of what is quick. I owned a GPZ 750 Turbo back in the 80's - not even in the same league. Doug Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 12, 2004 Share Posted September 12, 2004 Jon, what I did was update you on his current thinking which isn't necessarily on the website. he "thought" he needed the external gate. SO after a $1200+ custom manifold, the cost of the gate, sevearl flanges, etc etc etc he's got it all together, and wonders if all the money was needed to be spent at all. I have no vested interest either way, I just wonder how much money is spent on all these projects that need thiss or that, when in reality, properly engineered pieces are replaced needlessly. I would also not say in any way I characterized JeffP's work as "ghetto" anything. Matter of fact, if anything it's overbuilt for the application, to ensure long term reliability. But taking his lead, and applying his already proven path, you can eliminate about $10,000 in development costs he went through. Which is the reason he has the website up there: so anybody can use his model, and simply bolt together a particular HP level using his experience as a guide. I also note you are now at 400 to 500HP level, instead of the 350 you mentioned that evening... Building to 300-350 is different than 450-500 in both materials, and costs involved. Quote Link to comment Share on other sites More sharing options...
speeder Posted September 13, 2004 Share Posted September 13, 2004 I had a rather large hybrid that I could not control boost creep by the normal internal wastegate porting and installation of an oversize flapper valve. I use an HKS EVC-EZ Boost controller. Finally went to a 40mm Turbonetics Racegate and now boost control is rock solid. I can hold a constant setting from 8psi (the basic wastegate spring - controlled boost) on up to 20+ with no spikes or creep. I've heard of some who have made internal wastegates work at higher power/ flow rates, but that task whupped my butt. Here's what mine looks like. Quote Link to comment Share on other sites More sharing options...
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