Help! 89 2.5t running on 86 GLHS electronics....

[ShadowFromHell]

I've been driving my dads rampage that has a 89 2.5 t1 motor. All stock, with a mitsu turbo. It is a auto, with a GLHS IC. It is running a GLHS MP computer (I THINK, I know it is a MP unit). It is running +20 injectors. I have the timing set at 8 degree's. Boost is set to 14psi with a MBC. Now, Ive always thought dropping the timing from 12 to 8, and running +20's was the solution to running a 2.5 on a 2.2 cal. I do know the MP units do run leaner then a stock T2 LM.

The problem I am having is it is having "mid boost" knock. I know this, because I can hear it. Once it gets to full boost it goes away, but that may be due to the ECU pulling even more timing. I have a scanner to check knock, but that takes two people and I haven't had a chance to check it.

So what do I need to do to fix this. Has anyone ran this setup and had it work without the knock? I'd like to know before I go looking elsewhere for the problem, like the fuel system itself.

So has anyone else ran this type of setup without problems? I know it needs a cal to be correct, and that is in the plans. But it is not in the budget right now.

Thanks
Dustin

[turbovanman²]

Run premium, and or add some Xylene or Toluene to each tank, retard the timing more.

A cal from www.boostbutton.com is cheaper and easier than 4 ashtray's,

[ShadowFromHell]

Im currently running premium. I run it all my turbo cars . I was thinking of adding a AFR and adding a couple pounds, but Im also wondering if it doesnt have a weak pump/bad fuel filter. I really need to put my FPR gauge on it and drive it under load I guess.

I do plan on getting a 3bar cal for it (its my dads, but I am going to buy it from him) down the road. But, I want to add the 20g (and a few other things) before I do that, right now I would just like to get it running right at "stock" specs.

I MAY have a stock 87 daytona T2 LM in the garage. I think the rampage already has the under hood map. If it does, is the 87 T2 LM plug and play?

[x.Gen]

read my thread on the ostrich from early this year.

I converted to a 2.5 CB (last year I think), and had briefly run it on my MP II GLHS with +20's. I had backed down the timing quite a bit, I think the majority of the time I was actually running 6'. I wasn't datalogging at the time, so I can't say for sure it was knock - but I was NOT comfortable leaving the setup and decided it was time to come out of the dark ages. after much reading (there actually isn't a lot out there anymore on this cal/LM cals, since everyone seems to be running a vendor cal or turbonator these days), I realized what a bad idea it was running that setup, regardless of how many people said they ran it successfully. very glad I did it. when you read about pin placement on the 2.5 pistons, and then look at the actual timing curves - if you know enough about these engines (stock), no rational person would run it permanently like that. not without expecting a rebuild sooner than would otherwise be necessary.

the +20's are a weak band-aid for a festering wound on that combo. if you plan on running near/over 15 psi, you are begging for trouble if you ask me. I've fine tuned all the bugs out of the cal (I did use the MP as a base to tune from, and tweaked as I went) and the car is a pretty serious animal now, but well behaved where it matters (start-up/idle/coasting decel). no strip time to brag about, but after getting settled with the tune, had a run on open (4 lane) highway from 45 up against a 370z and mazda speed 3 or whatever they are called, at the same time - needless to say I absolutely destroyed them, it was hilarious. 2.5, +20's, stock turbo, .63 turbine, 3" SV and exhaust, no cat. had it set at about 15-16 psi when I did that. no exaggeration, it wasn't even close. that was the one time I let the whip really crack; I'm pretty conservative otherwise.

get a cal for it. get a garret while you're at it. could sell you a chip with my cal if you wanted, but your better off learning how to tune on your own in the long run. don't leave it like that. my .02.

[x.Gen]

just premium isn't enough to compensate for the MP's aggressive timing curves. Simon is right, you need a serious increase in octane for that. like I said, the timing curves are far too aggressive for a 2.5 without a bump in octane. I'd be moving the cal up the priority ladder if I were you, it is cheaper in the long run.

[ShadowFromHell]

Now, Do you consider it a band aid due to the timing maps being so far off?

[ShadowFromHell]

Also.. I dont know much about the cals, but are the timing maps different from a 87 T2 cal to a 86 MP cal? Would it be worth my time to swap in the 87 T2 cal? I thought I had read somewhere once that the only difference was that the MP cal ran leaner, but I could be wrong.

[turbovanman²]

Also.. I dont know much about the cals, but are the timing maps different from a 87 T2 cal to a 86 MP cal? Would it be worth my time to swap in the 87 T2 cal? I thought I had read somewhere once that the only difference was that the MP cal ran leaner, but I could be wrong.

86 will be a milder setup, IIRC, the T2 has a bit more timing.

Seriously, get a stock 2.5 cal made, then you can easily have it changed for like $25 down the road, it really is cheaper then a rebuild.

[ShadowFromHell]

Problem is Simon I haven't worked in 6 months. I am having the joy of fighting with LnI over my back problems. So buying a cal isn't a option. I guess if have to I will retard the timing more and maybe drop the boost. Ive been driving the rampage because my neon is so low that its hard for me to get in and out of. The rampage is about the perfect height.

Its running a 86 GLHS MP computer, not a 86 MP T1 BTW

[x.Gen]

I do know the MP units do run leaner then a stock T2 LM.

The problem I am having is it is having "mid boost" knock. I know this, because I can hear it.

I haven't compared the fuel curves in a while, but the MP II ADDS fuel (although it is mostly up top). IT IS THE TIMING CURVES making it knock. race gas is the only hope for it without a cal. listen to Simon on this one.

Im currently running premium. I run it all my turbo cars . I was thinking of adding a AFR and adding a couple pounds, but Im also wondering if it doesnt have a weak pump/bad fuel filter. I really need to put my FPR gauge on it and drive it under load I guess.

I MAY have a stock 87 daytona T2 LM in the garage. I think the rampage already has the under hood map. If it does, is the 87 T2 LM plug and play?

diagnose your fuel system ASAP. even a stock T2 LM has the WRONG TIMING CURVES for a 2.5. will it work? with pin changes in the harness, but you'll still have a knock issue. 2.2 curves are aggressive down low, just where you don't want it on a 2.5.

think about this: you can hear it knocking. unless your father is a smoker in need of a couple ash trays for the garage - GET A CAL! listen to Simon, and me on this. a cal is way cheaper than a rebuild.

[x.Gen]

Now, Do you consider it a band aid due to the timing maps being so far off?

yes!!!

[ShadowFromHell]

I turned the timing down to 4 degree's and the knock is almost gone, but it completely neutered it. It currently had champion 9's, I know there is better plug options out there now, would running the NGK's or the really cold autolites help?

It needs a cal badly. Thing is, with a 3 bar and 18psi even with the mitsu this thing is gonna SCOOT!

[Darkapollo]

18psi on a mitsu is going to do damage on its own..

[turbovanman²]

I turned the timing down to 4 degree's and the knock is almost gone, but it completely neutered it. It currently had champion 9's, I know there is better plug options out there now, would running the NGK's or the really cold autolites help?

It needs a cal badly. Thing is, with a 3 bar and 18psi even with the mitsu this thing is gonna SCOOT!

Then run some Toluene or Xylene, mixed 3 parts gas to 1 part of those, its 9 FULL octane points. Home Depot etc carry it.

[GLHNSLHT2]

I haven't compared the fuel curves in a while, but the MP II ADDS fuel (although it is mostly up top). IT IS THE TIMING CURVES making it knock. race gas is the only hope for it without a cal. listen to Simon on this one.
diagnose your fuel system ASAP. even a stock T2 LM has the WRONG TIMING CURVES for a 2.5. will it work? with pin changes in the harness, but you'll still have a knock issue. 2.2 curves are aggressive down low, just where you don't want it on a 2.5.

think about this: you can hear it knocking. unless your father is a smoker in need of a couple ash trays for the garage - GET A CAL! listen to Simon, and me on this. a cal is way cheaper than a rebuild.

I agree with all of this other than the fuel curves. THe MP stage 2 pulls fuel out of the WOT curve above a certain boost level.

I turned the timing down to 4 degree's and the knock is almost gone, but it completely neutered it. It currently had champion 9's, I know there is better plug options out there now, would running the NGK's or the really cold autolites help?

It needs a cal badly. Thing is, with a 3 bar and 18psi even with the mitsu this thing is gonna SCOOT!

No colder plugs won't help. A stock 87 T2 cal won't help either. If it's your dads car then why doesn't he pony up the cash for a correct calibration?

18psi on a mitsu is going to do damage on its own..

+1 to that. I wouldn't run anymore than 12 on mits and even then that's pushing it IMO.

[ShadowFromHell]

He isn't going to buy a cal, because he has lost ALL interest in it. He hasn't drove it in well over a year. I am going to buy it from him, but just cant financially right now. Next spring I will have the money. So, its probably going to sit until then, unless I have to move something (sold my truck).

Or maybe I could put a set of +40's in it and some E85? lol.

[1966 dart wagon]

if you wanna run e85 i would just go bigger then 40+s, i have them and am at about the limit with 20psi or so, I had to turn my base fuel pressure up to use it. Plus if your going that route, I would suggest doing your own cals IMO

[ShadowFromHell]

I was semi joking about the E85, the reason I said +40's is I have a set . Next spring when I buy it, Ill be getting a 3 bar call to use the +40's, a G-head, fmic, and 20g turbo. Hopefully will have built a new intake mani by then.

[x.Gen]

I agree with all of this other than the fuel curves. THe MP stage 2 pulls fuel out of the WOT curve above a certain boost level.

that's why I qualified it, been a while since I compared them - but the cal is anything but lean, as he thought. tried to stress the importance of the cal needing matching...too many people over the years wrote posts that lead me to believe it was a perfectly compatible match. that isn't what I would tell anyone who asked me. I'm glad he is not going to run it for a while, that's a better choice....

I was semi joking about the E85, the reason I said +40's is I have a set . Next spring when I buy it, Ill be getting a 3 bar call to use the +40's, a G-head, fmic, and 20g turbo. Hopefully will have built a new intake mani by then.

you've got +40's and need a cal. that mitsu isn't a great idea for more than a 2-bar would cover anyhow, as you're hearing...sounds like your +20's will hold for a while. I've been looking for a set of 'affordable' +40's for a while (too broke to justify a new set right away, and keep missing deals). PM me if you wanna talk a deal, I'll help you with your cal and cash flow issue