herbiemercman Posted January 26, 2020 Share Posted January 26, 2020 (edited) Hi Dudes, I had a fantastic NAT build with circa 400BHP and the torque to go with it, also it had a great spooling scream coming from the wastegate. So the stock head gasket,0.6 mm thick, failed on the no 1 cylinder and had to be replaced, very stressful job and expensive. I chose the TT thicker gasket at 1.3mm thick, six ply, much more robust and the stock ones are prone to failure. At the time i did not realize how much this change would compromise my engine's performance. The CR dropped from 10 to 1, to 9.5 to 1, this does not seem significant to the uninitiated like me, BUT i lost 25% of my BHP. If you are used to a certain power level, then the big power reduction is very noticeable. To restore the power i will have to shell out for bigger 550cc injectors, larger fuel pump and increase the wastegate boost spring, or buy an electronic boost controler, with labour and the re-mapping we are looking at big bucks. So if your head gasket fails and you only want to do the job once with the thicker 1.3mm gasket, then your looking at big bucks. The whole exercise has pissed me off, big time. Herbie. Edited January 26, 2020 by herbiemercman (see edit history) Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted January 26, 2020 Share Posted January 26, 2020 Top tip, do a GTE swap in the first place. Quote Link to comment Share on other sites More sharing options...
Mo Reviews Posted January 26, 2020 Share Posted January 26, 2020 I know someone who may sell their GTE, if you're interested... Quote Link to comment Share on other sites More sharing options...
TheTurtleshead Posted January 26, 2020 Share Posted January 26, 2020 Nothing wrong with a well executed NA-T build. Unfortunately I believe the OP was sold a dream about what he could expect for his money. Do it cheap, prepare to do it more than once! Quote Link to comment Share on other sites More sharing options...
sidewaysdan Posted January 26, 2020 Share Posted January 26, 2020 Herbie. Don't be to disheartened it’s not as bad as you may think.. you can get a set of 550 injectors on fleybay . Or maybe one of the lads on here maybe able to help.. a fuel pump will not set you back to much. I have a 300lph pump you can have for free as that will be fine fore 450+ hp Also you could just put a manual bleed valve on to adjust your boost. Also the map I would have thought will just need a tweak maybe a hrs or two to sort and setup and you will be back at or even better than before.. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted January 26, 2020 Author Share Posted January 26, 2020 (edited) Hi Turtleshead, Not sure where you got your believe info from? The build was great as promised, ran great for 3 years, it was my fault i had problems which i explained in my posts if you read them, the thicker head gasket was the problem, NOT the build it was good value for money, if you did the same to a top market build, the head gasket would cause a problem. I have found a way out of the problem, just adding improved fueling and more boost, i will also get benefits that the stage 1 did not give. Herbie. (The OP). Edited January 26, 2020 by herbiemercman (see edit history) Quote Link to comment Share on other sites More sharing options...
Mo Reviews Posted January 26, 2020 Share Posted January 26, 2020 Genuinely feel for you buddy. We've all been there and from my own experiences, it's not very pleasant. I'm doing some modifications at the moment and if I end up removing some of the aforementioned bits, I'll give you a shout. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted January 26, 2020 Author Share Posted January 26, 2020 Hi Dan, That is very good of you re the pump, the job now in hand is at an agreed price with parts, labour and a re-map. Herbie. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted January 26, 2020 Author Share Posted January 26, 2020 Hi Swampy & Adam, I have had my engine from new 42,000 miles back, so you can understand this is a good base for me, not a GTE, i just "fuc--d up" the stage 1 conversion with a head gasket mistake. Soon it will be sorted and i should end up with even better performance. Herbie. Quote Link to comment Share on other sites More sharing options...
Mo Reviews Posted January 26, 2020 Share Posted January 26, 2020 I'm not too clued up on the GE engines but I would imagine you would have needed to upgrade the head gasket at some point to handle the extra pressure, anyway... so don't beat yourself up too much bud, you did the right thing. Blowing your head gasket could have been catastrophic, losing a few ponies for a short while is a walk in the park by comparison. Quote Link to comment Share on other sites More sharing options...
Noz Posted January 26, 2020 Share Posted January 26, 2020 I don't really understand the issue. Adam's the only one who's admitted having no idea about GE engines. Hes also right. You risk power without changing the headgasket. Its been done but it's much higher risk. Everyone can wave the GTE flag but I dont really understand the issue. My NAt setup of 600hp has taught me only go the GTE route if you haven't got an NA. Otherwise you save money. But if I was going to do another project car. I'd make my life easier and go GTE in the first place and only due to components being cheaper and the setup being more ideal for 600hp. 25% power loss, Herb do you have a dyno curve to show this? I know you lose a bit of response but after my first NAt install when I got used to the power my perception changed and it felt slower not long after. Which is why everyone chases power. You've gone from 220hp to 400hp yet you're saying a drop in horsepower 25%. Before we all give you a shoulder to cry on mate is that a made up number or do you have a dyno showing rpm and hp rating. Where is your data. I fitted a TT gasket. Hardly noticed a difference. I have same compression as you. Ster clear of a GTE engine. Your need new harnesses. Ancillary components. Turbo manifolds. It's not just swap the long block. Its mega bucks. And they have a compression ratio even lower! Though a smaller turbo makes up for the difference. The compression ratio you have will be BETTER than a single turbo TT setup (typically unless they do a high compression engine build). So I dont understand your warning here mate? I dont get what you think you've screwed up? Does the car just feel delayed? A pump injectors and remap wont fix your problem. Itll only give you more power and not power low down. Thatll be fue to the tune itself. More fuel wont fix that IF its the problem. The parts you say you need dont give lower down response. The tune would be the important factor buddy. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted January 27, 2020 Author Share Posted January 27, 2020 (edited) Hi Noz, I am sorry i am having to be qualative and not quantative but i have not had a choice, most of my details have been supplied by the guy that did the build, Craig (RDR), also my boost gauge is only registering negative pressures. Following the head gasket job the and the reduction in CR, the only other issue, at the time was not being sure about the ignition timing, RDR said it was set at 8 degBTDC and the MAP takes care of it. So i noticed the reduction in performance and started enquiring on the site what i could do about it? The answers were bigger injectors 550cc, bigger fuel pump and increase the boost, and re-map, it made sense and i just spent a couple of weeks thinking about it, cost? who could do it,etc. Meanwhile i decided to change the stock exhaust system for a 3" Jap Parts free flow system, and the mechanic found the air pipe missing from the bottom of the wastegate and then the knott in the pipe. Craig DR said he wanted the pipe blocked at each end and was just running a wastegate spring gate at 12 PSI, he said the new exh would not affect the AFR and would not lean out, but he thought the exh would cause the wastegate to open too early and consequently reduce the boost considerably? Should i block off my pipe as per RDR? as it is now connected at both ends? I have looked at all the boost pipe connections and all look ok, could it be the problem all along is the wastegate loosing the boost.? What do you think? Herbie. Edited January 27, 2020 by herbiemercman (see edit history) Quote Link to comment Share on other sites More sharing options...
Mo Reviews Posted January 27, 2020 Share Posted January 27, 2020 I think you need to take your car back to the garage that built it. We can all sit here and try and remotely diagnose your issues but ultimately, these are all blind stabs in the dark. If you want your car fixed, I'd go back to the garage that built it and ask them to look at it... As Noz has confirmed, to achieve the power level you wanted to achieve, safely, you would have needed to replace your stock head gasket anyway. This will have lowered your compression and hopefully this is something your garage/tuner has/should accounted for. Quote Link to comment Share on other sites More sharing options...
Noz Posted January 27, 2020 Share Posted January 27, 2020 I still dont really understand what you're saying. Not sure if you're just frustrated or trying to explain yourself. But I'm finding a lot of your posts quite confusing I'm afraid. Make a small list of your issues and approach two options. 1. Take it back and resolve the issue with Craig. 2. Take it somewhere else and let them review it with your list. Stabs in the dark as Adam puts it, achieve nothing for you and speculation from others or yourself mate wont fix anything. Its guess work. Forum tuning is sadly unable to help. They are your only two options as I see it. I can recommend Whifbitz. Quote Link to comment Share on other sites More sharing options...
Style Posted January 27, 2020 Share Posted January 27, 2020 If your boost gauge isn't reading positive pressure then you may just have a major boost leak (disconnected intercooler pipe or something) which would explain the feeling of lost power. Make sure all your pipes from the turbo to the intake manifold are connected and check for boost leaks. A quick test would be to have the car running and cover the turbo intake with a hard back book or something, blocking off the air supply. If the car doesn't stall, it's getting air supply from somewhere else and it's a boost leak. Could literally be a 5 minute fix that saves your car. Return your wastegate hoses to what RDR had it as (in a knot by the sounds) and you're fine again. Quote Link to comment Share on other sites More sharing options...
Suprakeith Posted January 27, 2020 Share Posted January 27, 2020 Just out of interest what head bolts did you use? Quote Link to comment Share on other sites More sharing options...
Shane Posted January 27, 2020 Share Posted January 27, 2020 If your boost gauge isn't reading positive pressure then you may just have a major boost leak (disconnected intercooler pipe or something) which would explain the feeling of lost power. Make sure all your pipes from the turbo to the intake manifold are connected and check for boost leaks. A quick test would be to have the car running and cover the turbo intake with a hard back book or something, blocking off the air supply. If the car doesn't stall, it's getting air supply from somewhere else and it's a boost leak. Could literally be a 5 minute fix that saves your car. Return your wastegate hoses to what RDR had it as (in a knot by the sounds) and you're fine again. Exactly this. If your gauge isn't showing boost above atmosphere then your car will feel very different. Before you go too deep into head gasket and CR issues, get to the bottom of why it's not not boosting. You may have a pleasant, easy fix ahead! Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted January 28, 2020 Author Share Posted January 28, 2020 Hi Noz and Adam, I realize you are right re take car to a qualified tuner, they are all many miles away and Craig RDR is 500 miles there and back, you also have to leave the car for a few weeks. This is why i must bottom whether i have a boost issue like the last two posts are telling me. I accept i have been all over the place with the problem but that is how it has unfolded. I am grateful for your help, and hope you can see i must soldier on. I do have a final solution backup in place, recently agreed with Craig RDR, if i need it? Hi Style and Shane, Thank you for your comments, i will try the turbo idea. Hi Suprakeith, I purchased new HT cylinder head bolts. Herbie. Quote Link to comment Share on other sites More sharing options...
Noz Posted January 28, 2020 Share Posted January 28, 2020 Sounds like you have a boost leak. Zero boost would sound like a drop in power. Rather than a compression issue. Check all your intercooler couples and small vacuum hosing. Quote Link to comment Share on other sites More sharing options...
Suprakeith Posted January 28, 2020 Share Posted January 28, 2020 Ah ok reason I asked is cause I use stock n/a head gasket and I went with the ARP studs to prevent movement, it may not be down to head gasket being too thin or weak it could be under that under heavy load the head is lifting every so tiny and that has slowly caused the head gasket to wear and fail, I know a lot of na-t guys running over 400bhp with stock block and head gasket, but using ARP head studs and none of them have had any issues with gasket at all and few of them been like that for over 5years with out single issue. Just thought worth mentioning to try help out bud Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted January 28, 2020 Author Share Posted January 28, 2020 Maybe i should have retained the 0.6mm gasket and consequently would have retained my CR and performance, however at the time i was so pissed off with the gasket failure, pluming, water loss, overheating etc., that i wanted something to stop this happening again, which was the 5 laminate 1.3mm robust gasket. To be honest i like having this back up, as the replacement gasket job is a nightmare and £1,000 DIY job. I have still not found out what the true performance loss is? as many members in good faith give different quotes on this, i can not say until i sort out my boost issues. They say if you do not get problems you will not learn, BUT i would sooner not have the problems. lol. Herbie. Quote Link to comment Share on other sites More sharing options...
Noz Posted January 28, 2020 Share Posted January 28, 2020 Your compression ratio in my opinion has zero to do with any of your issues. Put the forum down... go find your boost leak mate! Less pondering more pipe checking! Quote Link to comment Share on other sites More sharing options...
Mk4Gaz Posted January 28, 2020 Share Posted January 28, 2020 Your compression ratio in my opinion has zero to do with any of your issues. Put the forum down... go find your boost leak mate! Less pondering more pipe checking!This! Any decent tuning garage can perform a boost leak test if you can't do it yourself Quote Link to comment Share on other sites More sharing options...
Shane Posted January 29, 2020 Share Posted January 29, 2020 Deffinitely! If your gauge is telling you that it's not producing boost then get that sorted first. Worth mentioning also that now you have reduced the CR a little, driving with no boost will feel even worse than it would have done with your original CR. So in other words the car is going to feel even slower. Get some boost into your life and you may well be able to forget the whole HG and CR thing. Quote Link to comment Share on other sites More sharing options...
walkerstrider Posted January 29, 2020 Share Posted January 29, 2020 Ah ok reason I asked is cause I use stock n/a head gasket and I went with the ARP studs to prevent movement, it may not be down to head gasket being too thin or weak it could be under that under heavy load the head is lifting every so tiny and that has slowly caused the head gasket to wear and fail, I know a lot of na-t guys running over 400bhp with stock block and head gasket, but using ARP head studs and none of them have had any issues with gasket at all and few of them been like that for over 5years with out single issue. Just thought worth mentioning to try help out bud I had stock bolts when I first built mine, head gasket blew only after wastegate failed and hit about 2 bar of boost! Changed gasket for stock na and used arp head bolts Now running over 400hp no issues Quote Link to comment Share on other sites More sharing options...
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